nRF905 - Nordic VLSI - Product.Network

PRODUCT SPECIFICATION

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 1 of 42 June 2006

FEATURES

APPLICATIONS

• True single chip GFSK transceiver in a small

32-pin package (32L QFN 5x5mm)

• ShockBurst™ mode for low power operation

• Power supply range 1.9 to 3.6 V

• Multi channel operation – ETSI/FCC

Compatible

• Channel switching time <650µs

• Extremely low cost Bill of Material (BOM)

• No external SAW filter

• Adjustable output power up to 10dBm

• Carrier detect for "listen before transmit"

protocols

• Data Ready signal when a valid data packet

is received or transmitted

• Address Match for detection of incoming

packet

• Automatic retransmission of data packet

• Automatic CRC and preamble generation

• Low supply current (TX), typical 9mA

@ -10dBm output power

• Low supply current (RX), typical 12.5mA

• Wireless data communication

• Alarm and security systems

• Home Automation

• Remote control

• Surveillance

• Automotive

• Telemetry

• Industrial sensors

• Keyless entry

• Toys

GENERAL DESCRIPTION

nRF905 is a single-chip radio transceiver for the 433/868/915 MHz ISM band. The

transceiver consists of a fully integrated frequency synthesiser, receiver chain with

demodulator, a power amplifier, a crystal oscillator and a modulator. The

ShockBurstTM feature automatically handles preamble and CRC. Configuration is

easily programmable by use of the SPI interface. Current consumption is very low, in

transmit only 9mA at an output power of -10dBm, and in receive mode 12.5mA. Built

in power down modes makes power saving easily realizable.

QUICK REFERENCE DATA

Parameter Value Unit

Minimum supply voltage 1.9 V

Maximum transmit output power 10 dBm

Data rate 50 kbps

Supply current in transmit @ -10dBm output power 9 mA

Supply current in receive mode 12.5 mA

Temperature range -40 to +85 °C

Typical Sensitivity -100 dBm

Supply current in power down mode 2.5

µΑ

Table 1 nRF905 quick reference data.

Single chip 433/868/915 MHz Transceiver nRF905

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 2 of 42 June 2006

ORDERING INFORMATION

Type Number Description Version

nRF905 IC 32L QFN 5x5mm -

nRF905-EVKIT 433 Evaluation kit 433MHz 1.0

nRF905-EVKIT 868/915 Evaluation kit 868/915MHz 1.0

Table 2 nRF905 ordering information.

BLOCK DIAGRAM

SPI

interface

ShockBurst

Demod

Dataslicer

Address

decode

CRC code/

decode

GFSK

filter

RX - reg.

Config-reg.

TX - reg.

TX - addr.

PA

LNA

IF BBF

Frequency

Synthesiser

Voltage

regulators Crystal

oscillator

MOSI (11)

MISO (10)

SCK (12)

CSN (13)

TRX_CE (1)

PWR_UP (2)

TX_EN (32)

CD (6)

AM (7)

DR (8)

uPCLK (3)

XC1 (14)

XC2 (15)

ANT1 (20)

ANT2 (21)

VDD_PA (19)

VSS (5)

VSS (16)

VSS (18)

VSS (22)

VSS (24)

VSS (27)

VSS (28)

VSS (29)

VSS (30)

VDD (4)

VDD (17)

VDD (25)

DVDD_1V2 (31)

IREF (23)

Manchester

encoder/

decoder

VSS (26)

VSS (9)

Figure 1 nRF905 with external components.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 3 of 42 June 2006

TABLE OF CONTENTS

1 Pin Functions.................................................................................................................... 4

2 Pin Assignment................................................................................................................. 5

3 Electrical Specifications ................................................................................................... 6

4 Current Consumption........................................................................................................ 8

5 Modes of Operation.......................................................................................................... 9

5.1 Active Modes........................................................................................................... 9

5.2 Power Saving Modes ............................................................................................... 9

5.3 nRF ShockBurst™ Mode......................................................................................... 9

5.4 Typical ShockBurst

TM

TX...................................................................................... 10

5.5 Typical ShockBurst

TM

RX ..................................................................................... 12

5.6 Power Down Mode ................................................................................................ 14

5.7 Standby Mode........................................................................................................ 14

6 Device Configuration...................................................................................................... 15

6.1 SPI Register Configuration.................................................................................... 15

6.2 SPI Instruction Set ................................................................................................. 16

6.3 SPI Timing............................................................................................................. 17

6.4 RF – Configuration Register Description .............................................................. 19

6.5 Register Contents................................................................................................... 20

7 Important Timing Data................................................................................................... 21

7.1 Device Switching Times........................................................................................ 21

7.2 ShockBurst

TM

TX timing ....................................................................................... 21

7.3 ShockBurstTM RX timing..................................................................................... 22

7.4 Preamble ................................................................................................................ 22

7.5 Time On Air........................................................................................................... 23

8 Peripheral RF Information.............................................................................................. 24

8.1 Crystal Specification.............................................................................................. 2 4

8.2 External Clock Reference ...................................................................................... 24

8.3 Microprocessor Output Clock................................................................................ 24

8.4 Antenna Output...................................................................................................... 25

8.5 Output Power Adjustment...................................................................................... 25

8.6 Modulation............................................................................................................. 25

8.7 Output Frequency................................................................................................... 26

8.8 PCB Layout and Decoupling Guidelines............................................................... 27

9 nRF905 features.............................................................................................................. 28

9.1 Carrier Detect......................................................................................................... 28

9.2 Address Match ....................................................................................................... 28

9.3 Data Ready............................................................................................................. 28

9.4 Auto Retransmit..................................................................................................... 29

9.5 RX Reduced Power Mode...................................................................................... 29

10 Package Outline.......................................................................................................... 30

10.1 Package marking.................................................................................................... 31

11 Application Examples ................................................................................................ 32

11.1 Differential Connection to a Loop Antenna........................................................... 32

11.2 PCB Layout Example; Differential Connection to a Loop Antenna...................... 33

11.3 Single ended connection to 50Ω antenna............................................................... 34

11.4 PCB Layout Example; Single Ended Connection to 50Ω Antenna....................... 3 6

12 Absolute Maximum Ratings....................................................................................... 38

13 Glossary of Terms...................................................................................................... 39

14 Definitions.................................................................................................................. 40

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 4 of 42 June 2006

1 PIN FUNCTIONS

Pin Name Pin function Description

1 TRX_CE Digital input Enables chip for receive and transmit

2 PWR_UP Digital input Power up chip

3 uPCLK Clock output Output clock, divided crystal oscillator full-swing clock

4 VDD Power Power supply (+3V DC)

5 VSS Power Ground (0V)

6 CD Digital output Carrier Detect

7 AM Digital output Address Match

8 DR Digital output Receive and transmit Data Ready

9 VSS Power Ground (0V)

10 MISO SPI - interface SPI output

11 MOSI SPI - interface SPI input

12 SCK SPI - Clock SPI clock

13 CSN SPI - enable SPI enable, active low

14 XC1 Analog Input Crystal pin 1/ External clock reference pin

15 XC2 Analog Output Crystal pin 2

16 VSS Power Ground (0V)

17 VDD Power Power supply (+3V DC)

18 VSS Power Ground

19 VDD_PA Power output Positive supply (1.8V) to nRF905 power amplifier

20 ANT1 RF Antenna interface 1

21 ANT2 RF Antenna interface 2

22 VSS Power Ground (0V)

23 IREF Analog Input Reference current

24 VSS Power Ground (0V)

25 VDD Power Power supply (+3V DC)

26 VSS Power Ground (0V)

27 VSS Power Ground (0V)

28 VSS Power Ground (0V)

29 VSS Power Ground (0V)

30 VSS Power Ground (0V)

31 DVDD_1V2 Power Low voltage positive digital supply output for de-coupling

32 TX_EN Digital input TX_EN=”1”TX mode, TX_EN=”0”RX mode

Table 3 nRF905 pin function.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 5 of 42 June 2006

2 PIN ASSIGNMENT

Figure 2 nRF905 pin assignment (top view) for a 32L QFN 5x5 package.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 6 of 42 June 2006

3 ELECTRICAL SPECIFICATIONS

Conditions: VDD = +3V VSS = 0V, TEMP = -40ºC to +85ºC (typical +27ºC)

Symbol Parameter (condition) Notes

Min. Typ. Max. Units

Operating conditions

VDD

Supply voltage 1.9 3.6 V

TEMP Operating temperature -40 85 ºC

Digital input/output

V

IH

HIGH level input voltage 0.7·VDD VDD

V

IL

LOW level input voltage VSS 0.3·VDD

V

Ci

Pin capacitance 5 pF

Ii

L

Pin leakage current 1) ±10 nA

V

OH

HIGH level output voltage (I

OH

=-0.5mA) VDD-0.3 VDD

V

OL

LOW level output voltage (I

OL

=0.5mA) VSS 0.3 V

General electrical specification

I

stby_eclk

Supply current in standby, uCLK enabled 2) 100 µA

I

stby_dclk

Supply current in standby, uCLK disabled 3) 12.5 µA

I

PD

Supply current in power down mode 4) 2.5 µA

I

SPI

Supply current in SPI programming 5) 20 µA

General RF conditions

f

OP

Operating frequency 6) 430 928 MHz

f

XTAL

Crystal frequency 7) 4 20 MHz

∆f Frequency deviation ±42 ±50 ±58 kHz

BR

Data rate 8) 50 kbps

f

CH433

Channel spacing for 433MHz band 100 kHz

f

CH868/915

Channel spacing for 868/915MHz band 200 kHz

Transmitter operation

P

RF10

Output power 10dBm setting 9) 7 10 11 dBm

P

RF6

Output power 6dBm setting 9) 3 6 9 dBm

P

RF-2

Output power –2dBm setting 9) -6 -2 2 dBm

P

RF-10

Output power -10dBm setting 9) -14 -10 -6 dBm

P

BW_-16

-16dBc bandwidth for modulated carrier 8) 173 kHz

P

BW_-24

-24dBc bandwidth for modulated carrier 8) 222 kHz

P

BW_-32

-32dBc bandwidth for modulated carrier 8) 238 kHz

P

BW_-36

-36dBc bandwidth for modulated carrier 8) 313 kHz

P

RF1

1

st

adjacent channel transmit power 10) -27 dBc

P

RF2

2

nd

adjacent channel transmit power 10) -54 dBc

I

TX10dBm

Supply current @ 10dBm output power 30

mA

I

TX-10dBm

Supply current @ -10dBm output power 9

mA

Receiver operation

I

RX

Supply current in receive mode 12.5 mA

RX

SENS

Sensitivity at 0.1%BER -100 dBm

RX

MAX

Maximum received signal 0 dBm

C/I

CO

C/I Co-channel 11) 13 dB

C/I

1ST

1

st

adjacent channel selectivity C/I 200kHz 11) -7 dB

C/I

2ND

2

nd

adjacent channel selectivity C/I 400kHz 11) -16 dB

C/I

+1M

Blocking at +1MHz 11) -40 dB

C/I

-1M

Blocking at -1MHz 11) -50 dB

C/I

-2M

Blocking at -2MHz 11) -63 dB

C/I

+5M

Blocking at +5MHz 11) -70 dB

C/I

-5M

Blocking at -5MHz 11) -65 dB

C/I

+10M

Blocking at +10MHz 11) -69 dB

C/I

-10M

Blocking at -10MHz 11) -67 dB

C/I

IM

Image rejection 11) -36 dB

Table 4 nRF905 electrical specifications.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 7 of 42 June 2006

1) Max value determined by design and characterization testing.

2) Output frequency is 4MHz load of external clock pin is 5pF, Crystal is 4MHz.

3) Crystal is 4MHz.

4) Pin voltages are VSS or VDD.

5) Chip in power down, SPI_SCK frequency is 1MHz.

6) Operates in the 433, 868 and 915 MHz ISM band.

7) The crystal frequency may be chosen from 5 different values (4, 8, 12, 16, and 20MHz)

8) Data is Manchester-encoded before GFSK modulation.

9) Optimum load impedance, please see peripheral RF information.

10) Channel width and channel spacing is 200kHz.

11) Channel Level +3dB over sensitivity, interfering signal a standard CW, image lies 2MHz above wanted.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 8 of 42 June 2006

4 CURRENT CONSUMPTION

MODE CRYSTAL

FREQ. [MHZ] OUTPUT

CLOCK

FREQ. [MHZ]

TYPICAL

CURRENT

Power Down 16 OFF 2.5 uA

Standby 4 OFF 12 uA

Standby 8 OFF 25 uA

Standby 12 OFF 27 uA

Standby 16 OFF 32 uA

Standby 20 OFF 46 uA

Standby 4 0.5 110 uA

Standby 8 0.5 125 uA

Standby 12 0.5 130 uA

Standby 16 0.5 135 uA

Standby 20 0.5 150 uA

Standby 4 1 130 uA

Standby 8 1 145 uA

Standby 12 1 150 uA

Standby 16 1 155 uA

Standby 20 1 170 uA

Standby 4 2 170 uA

Standby 8 2 185 uA

Standby 12 2 190 uA

Standby 16 2 195 uA

Standby 20 2 210 uA

Standby 4 4 260 uA

Standby 8 4 275 uA

Standby 12 4 280 uA

Standby 16 4 285 uA

Standby 20 4 300 uA

Rx @ 433 16 OFF 12.2 mA

Rx @ 868/915 16 OFF 12.8 mA

Reduced Rx 16 OFF 10.5 mA

Tx @ 10dBm 16 OFF 30 mA

Tx @ 6dBm 16 OFF 20 mA

Tx @ -2dBm 16 OFF 14 mA

Tx @ -10dBm 16 OFF 9 mA

Conditions: VDD = 3.0V, VSS = 0V, TA = 27ºC,

Load capacitance of external clock = 13pF, Crystal load capacitance = 12pF

Table 5 nRF905 current consumption.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 9 of 42 June 2006

5 MODES OF OPERATION

The nRF905 has two active (RX/TX) modes and two power-saving modes

5.1 Active

Modes

• ShockBurst™ RX

• ShockBurst™ TX

5.2 Power Saving Modes

• Power down and SPI - programming

• Standby and SPI - programming

The nRF905 mode is decided by the settings of TRX_CE, TX_EN and PWR_UP.

PWR_UP TRX_CE TX_EN Operating Mode

0 X X Power down and SPI – programming

1 0 X Standby and SPI – programming

1 X 0 Read data from RX register

1 1 0 Radio Enabled - ShockBurstTM RX

1 1 1 Radio Enabled - ShockBurstTM TX

Table 6 nRF905 operational modes.

5.3 nRF ShockBurst™ Mode

The nRF905 uses the Nordic Semiconductor ASA ShockBurst™ feature.

ShockBurstTM makes it possible to use the high data rate offered by the nRF905

without the need of a costly, high-speed micro controller (MCU) for data

processing/clock recovery. By placing all high speed signal processing related to RF

protocol on-chip, the nRF905 offers the application micro controller a simple SPI

interface, the data rate is decided by the interface-speed the micro controller itself sets

up. By allowing the digital part of the application to run at low speed, while

maximizing the data rate on the RF link, the nRF905 ShockBurst™ mode reduces the

average current consumption in applications. In ShockBurstTM RX, Address Match

(AM) and Data Ready (DR) notifies the MCU when a valid address and payload is

received respectively. In ShockBurstTM TX, the nRF905 automatically generates

preamble and CRC. Data Ready (DR) notifies the MCU that the transmission is

completed. All together, this means reduced memory demand in the MCU resulting in

a low cost MCU, as well as reduced software development time.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 10 of 42 June 2006

5.4 Typical ShockBurstTM TX

1. When the application MCU has data for a remote node, the address of the

receiving node (TX-address) and payload data (TX-payload) are clocked

into nRF905 via the SPI interface. The application protocol or MCU sets

the speed of the interface.

2. MCU sets TRX_CE and TX_EN high, this activates a nRF905

ShockBurst™ transmission.

3. nRF905 ShockBurst™:

• Radio is automatically powered up.

• Data packet is completed (preamble added, CRC calculated).

• Data packet is transmitted (100kbps, GFSK, Manchester-encoded).

• Data Ready is set high when transmission is completed.

4. If AUTO_RETRAN is set high, the nRF905 continuously retransmits the

packet until TRX_CE is set low.

5. When TRX_CE is set low, the nRF905 finishes transmitting the outgoing

packet and then sets itself into standby mode.

If TX_EN is set low while TRX_CE is kept high, the nRF905 finishes transmitting

the outgoing packet and then enter RX-mode in the channel already programmed in

the RF-CONFIG register.

The ShockBurstTM mode ensures that a transmitted packet that has started always

finishes regardless of what TRX_EN and TX_EN is set to during transmission. The

new mode is activated when the transmission is completed. Please see subsequent

chapters for detailed timing

For test purposes such as antenna tuning and measuring output power it is possible to

set the transmitter so that a constant carrier is produced. To do this TRX_CE must be

maintained high instead of being pulsed. In addition Auto Retransmit should be

switched off. After the burst of data has been sent then the device will continue to

send the unmodulated carrier.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 11 of 42 June 2006

SPI - programming

uController loading ADDR

and PAYLOAD data

(Configuration register if

changes since last TX/RX)

NO

YES

nRF ShockBurst TX

Generate CRC and preamble

Sending package

DR is set high when completed

Transmitter is

powered up

TRX_CE

= HI ?

AUTO_

RETRAN

= HI ?

YES

NO

YES

NO

ADDR PAYLOAD

Data Package

Bit in configuration

register

TRX_CE

= HI ?

Radio in Standby

TX_EN = HI

PWR_UP = HI

TRX_CE = LO

ADDR PAYLOAD CRC

Pre-

amble

DR is

set low

after pre-

amble

Figure 3 Flowchart ShockBurstTM transmit of nRF905.

NB: DR is set low under the following conditions after it has been set high:

• If TX_EN is set low

• If PWR_UP is set low

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 12 of 42 June 2006

5.5 Typical ShockBurstTM RX

1. ShockBurstTM RX is selected by setting TRX_CE high and TX_EN low.

2. After 650µs nRF905 is monitoring the air for incoming communication.

3. When the nRF905 senses a carrier at the receiving frequency, Carrier

Detect (CD) pin is set high.

4. When a valid address is received, Address Match (AM) pin is set high.

5. When a valid packet has been received (correct CRC found), nRF905

removes the preamble, address and CRC bits, and the Data Ready (DR)

pin is set high.

6. MCU sets the TRX_CE low to enter standby mode (low current mode).

7. MCU can clock out the payload data at a suitable rate via the SPI interface.

8. When all payload data is retrieved, nRF905 sets Data Ready (DR) and

Address Match (AM) low again.

9. The chip is now ready for entering ShockBurstTM RX, ShockBurstTM TX or

power down mode.

If TX_EN is set high while TRX_CE is kept high, the nRF905 would enter

ShockBurstTMTX and start a transmission according to the present contents in the SPI-

registers.

If TRX_CE or TX_EN is changed during an incoming packet, the nRF905 changes

mode immediately and the packet is lost. However, if the MCU is sensing the Address

Match (AM) pin, it knows when the chip is receiving an incoming packet and can

therefore decide whether to wait for the Data Ready (DR) signal or enter a different

mode.

To avoid spurious address matches it is recommended that the address length be 24

bits or higher in length. Small addresses such as 8 or 16 bits can often lead to

statistical failures due to the address being repeated as part of the data packet. This

can be avoided by using a longer address.

Each byte within the address should be unique. Repeating bytes within the address

reduces the effectiveness of the address and increases its susceptibility to noise hence

increasing the packet error rate. The address should also have several level shifts (i.e.

10101100) to reduce the statistical effect of noise and hence reduce the packet error

rate.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 13 of 42 June 2006

Figure 4 Flowchart ShockBurstTM receive of nRF905.

NO

YES

Receiver is

powered up

NO

YES

Receiving

data

Receiver

Sensing for incomming data

CD is set high if carrier

AM is set

high

NO

DR high is

set high

Radio enters

STBY

MCU clocks out payload via

the SPI interface

DR and AM are

set low

YES

NO

AM is set low

Radio in Standby

TX_EN = LO

PWR_UP = HI

TRX_CE

= HI ?

Correct

ADDR?

Correct

CRC?

TRX_CE

= HI ?

PAYLOAD

Data Package

ADDR PAYLOAD CRC

Pre-

amble

RX Remains

On

MCU clocks out payload via

the SPI interface

DR and AM are

set low

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 14 of 42 June 2006

5.6 Power Down Mode

In power down the nRF905 is disabled with minimal current consumption, typically

less than 2.5µA. When entering this mode the device is not active which will

minimize average current consumption and maximizing battery lifetime. The

configuration word content is maintained during power down.

5.7 Standby Mode

Standby mode is used to minimize average current consumption while maintaining

short start up times to ShockBurstTM RX and ShockBurstTM TX. In this mode part of

the crystal oscillator is active. Current consumption is dependent on crystal frequency,

Ex: IDD= 12µA @4MHz and IDD =46µA @20MHz. If the uP-clock (pin 3) of nRF905

is enabled, current consumption increases and is dependent on the load capacitance

and frequency. The configuration word content is maintained during standby.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 15 of 42 June 2006

6 DEVICE CONFIGURATION

All configuration of the nRF905 is via the SPI interface. The interface consists of five

registers; a SPI instruction set is used to decide which operation shall be performed.

The SPI interface can be activated in any mode however Nordic Semiconductor ASA

recommends the chip be in standby or power down mode.

6.1 SPI Register Configuration

The SPI interface consists of five internal registers. A register read-back mode is

implemented to allow verification of the register contents.

TX-PAYLOAD

EN

DTA

CLK

I/O-reg

CSN

MOSI

MISO

SCK

RF - CONFIGURATION

REGISTER

EN

DTA

CLK

TX-ADDRESS

EN

DTA

CLK

RX-PAYLOAD

EN

DTA

CLK

STATUS-REGISTER

EN

DTA

CLK

Figure 5 SPI – interface and the five internal registers.

Status – Register

Register contains status of Data Ready (DR) and Address Match (AM).

RF – Configuration Register

Register contains transceiver setup information such as frequency and output power

ext.

TX – Address

Register contains address of target device. How many bytes used is set in the

configuration register.

TX – Payload

Register containing the payload information to be sent in a ShockBurst TM packet.

How many bytes used is set in the configuration register.

RX – Payload

Register containing the payload information derived from a received valid

ShockBurst TM packet. How many bytes used is set in the configuration register. Valid

data in the RX-Payload register is indicated with a high Date Ready (DR) signal.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 16 of 42 June 2006

6.2 SPI Instruction Set

The available commands to be used on the SPI interface is shown below. Whenever

CSN is set low the interface expects an instruction. Every new instruction must be

started by a high to low transition on CSN.

Instruction set for the nRF905 SPI Serial Interface

Instruction Name Instruction

Format Operation

W_CONFIG

(WC) 0000 AAAA Write Configuration-register. AAAA indicates which byte

the write operation is to be started from. Number of bytes

depends on start address AAAA.

R_CONFIG

(RC) 0001 AAAA Read Configuration-register. AAAA indicates which byte

the read operation is to be started from. Number of bytes

depends on start address AAAA.

W_TX_PAYLOAD

(WTP) 0010 0000 Write TX-payload: 1 – 32 bytes. A write operation will

always start at byte 0.

R_TX_PAYLOAD

(RTP) 0010 0001 Read TX-payload: 1 – 32 bytes. A read operation will

always start at byte 0.

W_TX_ADDRESS

(WTA) 0010 0010 Write TX-address: 1 – 4 bytes. A write operation will

always start at byte 0.

R_TX_ADDRESS

(RTA) 0010 0011 Read TX-address: 1 – 4 bytes. A read operation will

always start at byte 0

R_RX_PAYLOAD

(RRP) 0010 0100 Read RX-payload: 1 – 32 bytes. A read operation will

always start at byte 0.

CHANNEL_CONFIG

(CC) 1000 pphc

cccc cccc Special command for fast setting of CH_NO,

HFREQ_PLL and PA_PWR in the CONFIGURATION

REGISTER. CH_NO= ccccccccc, HFREQ_PLL = h

PA_PWR = pp

STATUS REGISTER N.A. The content of the status-register (S[7:0]) will always be

read to MISO after a high to low transition on CSN as

shown in Figure 6 and 7.

Table 7 Instruction set for the nRF905 SPI interface.

A read or a write operation may operate on a single byte or on a set of succeeding

bytes from a given start address defined by the instruction. When accessing

succeeding bytes one will read or write MSB of the byte with the smallest byte

number first.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 17 of 42 June 2006

6.3 SPI Timing

The interface supports SPI mode 0. SPI operation and timing is given in Figure 6 to

Figure 8 and in Table 8. The device must be in one of the power saving modes for the

configuration registers to be read or written to.

C7 C6 C5 C4 C3 C2 C1 C0

S7 S6 S5 S4 S3 S2 S1 S0 D7 D6 D5 D4 D3 D2 D1 D0 D 1 5

D1 4

D1 3

D1 2

D1 1

D1 0

D9 D8

CSN

SCK

MOSI

MISO

Figure 6 SPI read operation.

C 7 C 6 C5 C 4 C3 C2 C 1 C0 D7 D6 D 5 D4 D 3 D2 D 1 D0 D1 5 D1 4 D 1 3 D 1 2 D 1 1 D 1 0 D9 D 8

S7 S6 S5 S4 S3 S2 S1 S0

CSN

SCK

MOSI

MISO

Figure 7 SPI write operation.

C7 C6 C0

S7 S0

TcdzTcdTcsd

Tdh

Tdc

TcchTclTclTchTcc Tch

TcwhTcwh

CSN

SCK

MOSI

MISO

Figure 8 SPI NOP timing diagram.

PRODUCT SPECIFICATION

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Revision: 1.4 Page 18 of 42 June 2006

PARAMETER SYMBOL MIN MAX UNITS

Data to SCK Setup Tdc 5 ns

SCK to Data Hold Tdh 5 ns

CSN to Data Valid Tcsd 45 ns

SCK to Data Valid Tcd 45 ns

SCK Low Time Tcl 40 ns

SCK High Time Tch 40 ns

SCK Frequency Tsck DC 10 MHz

SCK Rise and Fall Tr,Tf 100 ns

CSN to SCK Setup Tcc 5 ns

SCK to CSN Hold Tcch 5 ns

CSN Inactive time Tcwh 500 ns

CSN to Output High Z Tcdz 45 ns

Table 8 SPI timing parameters (Cload = 10pF).

PRODUCT SPECIFICATION

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Revision: 1.4 Page 19 of 42 June 2006

6.4 RF – Configuration Register Description

Parameter Bitwidth Description

CH_NO 9 Sets center freq. together with HFREQ_PLL (default = 001101100

b

= 108

d

).

f

RF

= ( 422.4 + CH_NO

d

/10)*(1+HFREQ_PLL

d

) MHz

HFREQ_

PLL 1 Sets PLL in 433 or 868/915 MHz mode (default = 0).

'0' – Chip operating in 433MHz band

'1' – Chip operating in 868 or 915 MHz band

PA_PWR 2 Output power (default = 00).

'00' -10dBm

'01' -2dBm

'10' +6dBm

'11' +10dBm

RX_RED_

PWR 1 Reduces current in RX mode by 1.6mA. Sensitivity is reduced (default = 0).

'0' – Normal operation

'1' – Reduced power

AUTO_

RETRAN 1 Retransmit contents in TX register if TRX_CE and TXEN are high (default = 0).

'0' – No retransmission

'1' – Retransmission of data packet

RX_AFW 3 RX-address width (default = 100).

'001' – 1 byte RX address field width

'100' – 4 byte RX address field width

TX_AFW 3 TX-address width (default = 100).

'001' – 1 byte TX address field width

'100' – 4 byte TX address field width

RX_PW 6 RX-payload width (default = 100000).

'000001' – 1 byte RX payload field width

'000010' – 2 byte RX payload field width

.

'100000' – 32 byte RX payload field width

TX_PW 6 TX-payload width (default = 100000).

'000001' – 1 byte TX payload field width

'000010' – 2 byte TX payload field width

.

'100000' – 32 byte TX payload field width

RX_

ADDRESS 32 RX address identity. Used bytes depend on RX_AFW (default = E7E7E7E7

h

).

UP_CLK_

FREQ 2 Output clock frequency (default = 11).

'00' – 4MHz

'01' – 2MHz

'10' – 1MHz

'11' – 500kHz

UP_CLK_

EN 1 Output clock enable (default = 1).

'0' – No external clock signal available

'1' – External clock signal enabled

XOF 3 Crystal oscillator frequency. Must be set according to external crystal resonant-

frequency (default = 100).

'000' – 4MHz

'001' – 8MHz

'010' – 12MHz

'011' – 16MHz

'100' – 20MHz

CRC_EN 1 CRC – check enable (default = 1).

'0' – Disable

'1' – Enable

CRC_

MODE 1 CRC – mode (default = 1).

'0' – 8 CRC check bit

'1' – 16 CRC check bit

Table 9 Configuration-register description.

PRODUCT SPECIFICATION

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Revision: 1.4 Page 20 of 42 June 2006

6.5 Register Contents

RF-CONFIG_REGISTER (R/W)

Byte # Content bit[7:0], MSB = bit[7] Init value

0 CH_NO[7:0]

0110_1100

1 bit[7:6] not used, AUTO_RETRAN, RX_RED_PWR, PA_PWR[1:0],

HFREQ_PLL, CH_NO[8]

0000_0000

2 bit[7] not used, TX_AFW[2:0] , bit[3] not used, RX_AFW[2:0]

0100_0100

3 bit[7:6] not used, RX_PW[5:0]

0010_0000

4 bit[7:6] not used, TX_PW[5:0]

0010_0000

5 RX_ADDRESS (device identity) byte 0

E7

6 RX_ADDRESS (device identity) byte 1

E7

7 RX_ADDRESS (device identity) byte 2

E7

8 RX_ADDRESS (device identity) byte 3

E7

9 CRC_MODE,CRC_EN, XOF[2:0], UP_CLK_EN, UP_CLK_FREQ[1:0]

1110_0111

TX_PAYLOAD (R/W)

Byte # Content bit[7:0], MSB = bit[7] Init value

0 TX_PAYLOAD[7:0]

X

1 TX_PAYLOAD[15:8]

X

- -

X

- -

X

30 TX_PAYLOAD[247:240]

X

31 TX_PAYLOAD[255:248]

X

TX_ADDRESS (R/W)

Byte # Content bit[7:0], MSB = bit[7] Init value

0 TX_ADDRESS[7:0]

E7

1 TX_ADDRESS[15:8]

E7

2 TX_ADDRESS[23:16]

E7

3 TX_ADDRESS[31:24]

E7

RX_PAYLOAD (R)

Byte # Content bit[7:0], MSB = bit[7] Init value

0 RX_PAYLOAD[7:0]

X

1 RX_PAYLOAD[15:8]

X

-

X

-

X

30 RX_PAYLOAD[247:240]

X

31 RX_PAYLOAD[255:248]

X

STATUS_REGISTER (R)

Byte # Content bit[7:0], MSB = bit[7] Init value

0

AM, bit [6] not used, DR, bit [0:4] not used X

Table 10 RF register contents.

The length of all registers is fixed. However, the bytes in TX_PAYLOAD,

RX_PAYLOAD, TX_ADDRESS and RX_ADDRESS used in ShockBurst TM RX/TX

are set in the configuration register. Register content is not lost when the device enters

one of the power saving modes.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

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Revision: 1.4 Page 21 of 42 June 2006

7 IMPORTANT TIMING DATA

The following timing must be obeyed during nRF905 operation.

7.1 Device Switching Times

nRF905 timing Max.

PWR_DWN  ST_BY mode 3 ms

STBY  TX ShockBurst™ 650 µs

STBY  RX ShockBurst™ 650 µs

RX ShockBurst™  TX ShockBurst™ 550 1µs

TX ShockBurst™  RX ShockBurst™ 550 1µs

Notes to table:

1) RX to TX or TX to RX switching is available without re-programming of the RF

configuration register. The same frequency channel is maintained.

Table 11 Switching times for nRF905.

7.2 ShockBurstTM TX timing

M O S I

C S N

P W R _ U P

T X _ E N

T R X _ C E

T X D A TA

T IM E

T 0 = R a d io E na bled

T 1 = T 0+ 10 uS M in im u m T R X _C E p u lse

T 2 = T 0 + 6 50 u S.S ta rt of T X D ata tra n s m issio n

T 3 = E nd of D a ta P a cke t, e nte r S tan d b y m od e

P ro g ra m m ing of

C on fig u ra tio n R eg is te r

an d T X D a ta R egis ter

T 0 T 1 T 2 T 3

T ra ns m itte d D ata 10 0 kb p s

M an ch e ste r E nc o d ed

Figure 9 Timing diagram for standby to transmit.

After a data packet has finished transmitting the device will automatically enter

Standby mode and wait for the next pulse of TRX_CE. If the Auto Re-Transmit

function is enabled the data packet will continue re-sending the same data packet until

TRX_CE is set low.

PRODUCT SPECIFICATION

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Revision: 1.4 Page 22 of 42 June 2006

7.3 ShockBurstTM RX timing

P W R _ U P

T X _ E N

T R X _ C E

R X D A TA

T IM E

A M

D R

C D

T 0 = R e ce iv e r E n a ble d -L is te nin g fo r D a ta

T 1 = C a rrie r D e te ct fin ds a c arrie r

T 2 = A M - C o rre c t A d d re s s F o u n d

T 3 = D R - D ata p ac k et w ith c o rre c t A d d re ss /C R C

6 5 0 u S to e n te r R X

m o d e fro m

T R X _ C E b ein g s e t

h ig h.

T 0 T 1 T 2 T 3

650uS

Figure 10 Timing diagram for standby to receiving.

After the Data Ready (DR) has been set high a valid data packet is available in the RX

data register. This may be clocked out in RX mode or standby mode. After the data

has been clocked out via the SPI interface the Data Ready (DR) and Address Match

(AM) pins are reset to low.

The RX register is reset if the PWR_UP pin is taken low or if the device is switched

into TX mode i.e. TXEN is taken high. This will also results in the Data Ready(DR)

and Address Match (AM) pins being reset to low.

7.4 Preamble

In each data-packet transmitted by the nRF905 a preamble is added automatically.

The preamble is a predefined bit-sequence used to adjust the receiver for optimal

performance. A ten-bit sequence is used as preamble in nRF905. The length of the

preamble, tpreamble, is then 200µs.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

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Revision: 1.4 Page 23 of 42 June 2006

7.5 Time On Air

The time-on-air is the sum of the radio start-up time and the data-packet length. The

length of the preamble, address field, payload and CRC-checksum give the data-

packet length while the radio start-up time is given in Table 11. While preamble

length and start-up time are fixed the user sets the other parameters in the RF-

configuration register. The below equation shows how to calculate TOA

BR

NNN

ttTOA CRCpayloadaddress

preamblestartup ++

++=

tstartup and tpreamble are RF-start-up time and preamble time respectively. Naddress, Npayload

and NCRC are numbers of bits in the address, payload and CRC-checksum while BR is

the bitrate, which is equal to 50kbps.

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Revision: 1.4 Page 24 of 42 June 2006

8 PERIPHERAL RF INFORMATION

8.1 Crystal Specification

Tolerance includes initially accuracy and tolerance over temperature and aging.

Frequency CL ESR C0max Tolerance @

868/915 MHz Tolerance @

433 MHz

4MHz 8pF – 16pF 150Ω 7.0pF ±30ppm ±60ppm

8MHz 8pF – 16pF 100Ω 7.0pF ±30ppm ±60ppm

12MHz 8pF – 16pF 100Ω 7.0pF ±30ppm ±60ppm

16MHz 8pF – 16pF 100Ω 7.0pF ±30ppm ±60ppm

20MHz 8pF – 16pF 100Ω 7.0pF ±30ppm ±60ppm

Table 12 Crystal specification of nRF905.

To achieve a crystal oscillator solution with low power consumption and fast start-up

time, it is recommended to specify the crystal with a low value of crystal load

capacitance. Specifying a lower value of crystal parallel equivalent capacitance,

Co=1.5pF is also good, but this can increase the price of the crystal itself. Typically

Co=1.5pF at a crystal specified for Co_max=7.0pF.

The crystal load capacitance, CL, is given by:

22221111

21

'',

''

IPCBIPCBL

CCCCandCCCCwhere

CC

C++=++=

+

⋅

=

C1 and C2 are 0603 SMD capacitors as shown in the application schematics. CPCB1 and

CPCB2 are the layout parasitic on the circuit board. CI1 and CI2 are the capacitance seen

into the XC1 and XC2 pin respectively; the value is typical 1pF.

8.2 External Clock Reference

An external reference clock, such as a MCU clock, may be used instead of a crystal.

The clock signal should be applied directly to the XC1 pin, the XC2 pin can be left

high impedance. When operating with an external clock instead of a crystal the clock

must be applied in standby mode to achieve low current consumption. If the device is

set into standby mode with no external clock or crystal then the current consumption

will increase up to a maximum of 1mA.

8.3 Microprocessor Output Clock

By default a microprocessor clock output is provided. Providing an output clock will

increase the current consumption in standby mode. The current consumption in

standby will depend on frequency and load of external crystal, frequency of output

clock and capacitive load of the provided output clock. Typical current consumption

values are found in Table 5.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

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Revision: 1.4 Page 25 of 42 June 2006

8.4 Antenna Output

The “ANT1 & ANT2” output pins provide a balanced RF output to the antenna. The

pins must have a DC path to VDD_PA, either via a RF choke or via the center point

in a dipole antenna. The load impedance seen between the ANT1/ANT2 outputs

should be in the range 200-700Ω. The optimum differential load impedance at the

antenna ports is given as:

900MHz 225Ω+j210

430MHz 300Ω+j100

A low load impedance (for instance 50Ω) can be obtained by fitting a simple

matching network or a RF transformer (balun). Further information regarding balun

structures and matching networks may be found in the Application Examples chapter.

8.5 Output Power Adjustment

The power amplifier in nRF905 can be programmed to four different output power

settings by the configuration register. By reducing output power, the total TX current

is reduced.

Power setting RF output power DC current consumption

00 -10 dBm 9.0 mA

01 -2 dBm 14.0 mA

10 6 dBm 20.0 mA

11 10 dBm 30.0 mA

Conditions: VDD = 3.0V, VSS = 0V, TA = 27ºC, Load impedance = 400 Ω.

Table 13 RF output power setting for the nRF905.

8.6 Modulation

The modulation of nRF905 is Gaussian Frequency Shift Keying (GFSK) with a data-

rate of 100kbps. Deviation is ±50kHz. GFSK modulation results in a more bandwidth

effective transmission-link compared with ordinary FSK modulation.

The data is internally Manchester encoded (TX) and Manchester decoded (RX). That

is, the effective symbol-rate of the link is 50kbps. By using internally Manchester

encoding, no scrambling in the microcontroller is needed.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

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Revision: 1.4 Page 26 of 42 June 2006

8.7 Output Frequency

The operating RF-frequency of nRF905 is set in the configuration register by CH_NO

and HFREQ_PLL. The operating frequency is given by:

MHzPLLHFREQNOCHf

OP

)_1())10/_(4.422(

+

⋅

+

=

When HFREQ_PLL is ‘0’ the frequency resolution is 100kHz and when it is ‘1’ the

resolution is 200kHz.

The application operating frequency has to be chosen to apply with the Short Range

Devise regulation in the area of operation.

Operating frequency HFREQ_PLL CH_NO

430.0 MHz [0] [001001100]

433.1 MHz [0] [001101011]

433.2 MHz [0] [001101100]

434.7 MHz [0] [001111011]

862.0 MHz [1] [001010110]

868.2 MHz [1] [001110101]

868.4 MHz [1] [001110110]

869.8 MHz [1] [001111101]

902.2 MHz [1] [100011111]

902.4 MHz [1] [100100000]

927.8 MHz [1] [110011111]

Table 14 Examples of real operating frequencies.

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Revision: 1.4 Page 27 of 42 June 2006

8.8 PCB Layout and Decoupling Guidelines

nRF905 is an extremely robust RF device due to internal voltage regulators and

requires the minimum of RF layout protocols. However the following design rules

should still be incorporated into the layout design.

A PCB with a minimum of two layers including a ground plane is recommended for

optimum performance. The nRF905 DC supply voltage should be decoupled as close

as possible to the VDD pins with high performance RF capacitors. It is preferable to

mount a large surface mount capacitor (e.g. 4.7µF tantalum) in parallel with the

smaller value capacitors. The nRF905 supply voltage should be filtered and routed

separately from the supply voltages of any digital circuitry.

Long power supply lines on the PCB should be avoided. All device grounds, VDD

connections and VDD bypass capacitors must be connected as close as possible to the

nRF905 IC. For a PCB with a topside RF ground plane, the VSS pins should be

connected directly to the ground plane. For a PCB with a bottom ground plane, the

best technique is to place via holes as close as possible to the VSS pins. A minimum

of one via hole should be used for each VSS pin.

Full swing digital data or control signals should not be routed close to the crystal or

the power supply lines.

A fully qualified RF-layout for the nRF905 and its surrounding components,

including antennas and matching networks, can be downloaded from

www.nordicsemi.no.

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Revision: 1.4 Page 28 of 42 June 2006

9 nRF905 FEATURES

9.1 Carrier Detect.

When the nRF905 is in ShockBurst TM RX, the Carrier Detect (CD) pin is set high if a

RF carrier is present at the channel the device is programmed to. This feature is very

effective to avoid collision of packets from different transmitters operating at the

same frequency. Whenever a device is ready to transmit it could first be set into

receive mode and sense whether or not the wanted channel is available for outgoing

data. This forms a very simple listen before transmit protocol. Operating Carrier

Detect (CD) with Reduced RX Power mode is an extremely power efficient RF

system. Typical Carrier Detect level (CD) is typically 5dB lower than sensitivity, i.e.

if sensitivity is –100dBm then the Carrier Detect function will sense a carrier wave as

low as –105dBm. Below –105dBm the Carrier Detect signal will be low, i.e. 0V.

Above –95dBm the Carrier Detect signal will be high, i.e. Vdd. Between

approximately -95 to -105 the Carrier Detect Signal will toggle.

9.2 Address Match

When the nRF905 is in ShockBurst TM RX mode, the Address Match (AM) pin is set

high as soon as an incoming packet with an address that is identical with the device’s

own identity is received. With the Address Match pin the controller is alerted that the

nRF905 is receiving data actually before the Data Ready (DR) signal is set high. If the

Data Ready (DR) pin is not set high i.e. the CRC is incorrect then the Address Match

(AM) pin is reset to low at the end of the received data packet. This function can be

very useful for an MCU. If Address Match (AM) is high then the MCU can make a

decision to wait and see if Data Ready (DR) will be set high indicating a valid data

packet has been received or ignore that a possible packet is being received and switch

modes.

9.3 Data Ready

The Data Ready (DR) signal makes it possible to largely reduce the complexity of the

MCU software program.

In ShockBurst TM TX, the Data Ready (DR) signal is set high when a complete packet

is transmitted, telling the MCU that the nRF905 is ready for new actions. It is reset to

low at the start of a new packet transmission or when switched to a different mode i.e.

receive mode or standby mode.

In ShockBurst TM TX Auto Retransmit the Data Ready (DR) signal is set high at the

beginning of the pre-amble and is set low at the end of the preamble. The Data Ready

(DR) signal therefore pulses at the beginning of each transmitted data packet.

In ShockBurst TM RX, the signal is set high when nRF905 has received a valid packet,

i.e. a valid address, packet length and correct CRC. The MCU can then retrieve the

payload via the SPI interface. The Data Ready (DR) pin is reset to low once the data

has been clocked out of the data buffer or the device is switched to transmit mode.

PRODUCT SPECIFICATION

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Revision: 1.4 Page 29 of 42 June 2006

9.4 Auto Retransmit

One way to increase system reliability in a noisy environment or in a system without

collision control is to transmit a packet several times. This is easily accomplished with

the Auto Retransmit feature in nRF905. By setting the AUTO_RETRAN bit to “1” in

the configuration register, the circuit keeps sending the same data packet as long as

TRX_CE and TX_EN are high. As soon as TRX_CE is set low the device will finish

sending the packet it is currently transmitting and then return to standby mode.

9.5 RX Reduced Power Mode

To maximize battery lifetime in application where the nRF905 high sensitivity is not

necessary; nRF905 offers a built in reduced power mode. In this mode, the receive

current consumption reduces from 12.5mA to only 10.5mA. The sensitivity is reduced

to typical –85dBm, ±10dB. Some degradation of the nRF905 blocking performance

should be expected in this mode. The reduced power mode is an excellent option

when using Carrier Detect to sense if the wanted channel is available for outgoing

data.

PRODUCT SPECIFICATION

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Revision: 1.4 Page 30 of 42 June 2006

10 PACKAGE OUTLINE

nRF905 uses the QFN 32L 5x5 green package with a mat tin finish. Dimensions are in

mm. Recommended soldering reflow profile can be found in application note

nAN400-08, QFN soldering reflow guidelines, www.nordicsemi.no.

+

Package Type A A1 A2 b D E e J K L

QFN32

(5x5 mm) Min

typ.

Max

0.8

0.9

0.0

0.05

0.65

0.69

0.18

0.23

0.3

5 BSC

0.5 BSC 3.2

3.3

3.4

3.2

3.3

3.4

0.3

0.4

0.5

Figure 11 nRF905 package outline.

PRODUCT SPECIFICATION

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Revision: 1.4 Page 31 of 42 June 2006

10.1 Package marking

Figure 12 nRF905 package marking layout

Abbreviations:

DDDDDD – Product number, e.g. 905

B Build Code, i.e. unique code for silicon revision, production site,

package type and test platform

X – "X" grade, i.e. Engineering Samples (optional)

YY – 2 digit Year number

WW – 2 digit Week number

LL – 2 letter wafer lot number code

n

R

F

B

X

D

Y

W

L

PRODUCT SPECIFICATION

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Revision: 1.4 Page 32 of 42 June 2006

11 APPLICATION EXAMPLES

11.1 Differential Connection to a Loop Antenna

C2

22pF

0603

C6

4.7nF

0603

C5

33pF

0603

R2

22K

0603

C7

10nF

0603

VDD

C1

22pF

0603

R1

1M

X1

16 MHz

TRX_CE

1VSS 24

VSS 18

VDD 17

VSS

16

PWR_UP

2

uPCLK

3

VDD

4

VSS

5

CD

6

AM

7

DR

8

VSS

9

MISO

10

MOSI

11

SCK

12

XC2

15 XC1

14 CSN

13

VDD_PA 19

ANT1 20

ANT2 21

VSS 22

IREF 23

nRF905

VDD 25

VSS 26

VSS 27

VSS 28

VSS 29

VSS 30

DVDD_1V2 31

TXEN 32

U1

nRF905

VDD

C4

3.3nF

0603

C8

33pF

0603

VDD

TXEN

TRX_CE

PWR_UP

CD

AM

DR

SPI_MISO

SPI_MOSI

SPI_SCK

SPI_CSN

uPCLK

C3

180pF

C10

6.8pF

C11

4.7pF

aaaaaaaa

J1

Loop Antenna, 433MHz

35x20mm

C9

3.9pF

aaaaaaaa

C12

27pF

C13

27pF

Figure 13 nRF905 Application schematic, differential connection to a loop antenna

(433MHz).

Component Description Size Value Tol. Units

C1 NP0 ceramic chip capacitor, (Crystal oscillator) 0603 22 ±5% pF

C2 NP0 ceramic chip capacitor, (Crystal oscillator) 0603 22 ±5% pF

C3 NP0 ceramic chip capacitor, (PA supply decoupling) 0603 180 ±5% pF

C4 X7R ceramic chip capacitor, (PA supply decoupling) 0603 3.3 ±10% nF

C5 NP0 ceramic chip capacitor, (Supply decoupling) 0603 33 ±5% pF

C6 X7R ceramic chip capacitor, (Supply decoupling) 0603 4.7 ±10% nF

C7 X7R ceramic chip capacitor, (Supply decoupling) 0603 10 ±10% nF

C8 NP0 ceramic chip capacitor, (Supply decoupling) 0603 33 ±5% pF

C9 NP0 ceramic chip capacitor, (Antenna tuning) 0603 3.9 ±0.1 pF

C10 NP0 ceramic chip capacitor, (Antenna tuning)

0603 6.8 ±0.1 pF

C11 NP0 ceramic chip capacitor, (Antenna tuning)

0603 4.7 ±0.1 pF

C12 NP0 ceramic chip capacitor, (Antenna tuning) 0603 27 ±5% pF

C13 NP0 ceramic chip capacitor, (Antenna tuning) 0603 27 ±5% pF

R1 0.1W chip resistor, (Crystal oscillator bias) 0603 1 ±5% MΩ

R2 0.1W chip resistor, (Reference bias)

0603 22 ±1% kΩ

U1 nRF905 Transceiver QFN32L/5x5

X1 Crystal, C

L

= 12pF LxWxH =

4.0x2.5x0.8 16 ±60ppm MHz

Table 15 Recommended external components, differential connection to a loop

antenna (433MHz).

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 33 of 42 June 2006

11.2 PCB Layout Example; Differential Connection to a Loop Antenna

Figure 14 shows a PCB layout example for the application schematic in Figure 13. A

double-sided FR-4 board of 1.6mm thickness is used. This PCB has a ground plane on

the bottom layer. Additionally, there are ground areas on the component side of the

board to ensure sufficient grounding of critical components. A large number of via

holes connect the top layer ground areas to the bottom layer ground plane. There is no

ground plane beneath the antenna.

a) Top silk screen

No components in bottom layer

b) Bottom silk screen

c) Top view

d) Bottom view

Figure 14 PCB layout example for nRF905, differential connection to a loop antenna.

A fully qualified RF-layout for the nRF905 and its surrounding components,

including antennas and matching networks, can be downloaded from

www.nordicsemi.no.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 34 of 42 June 2006

11.3 Single ended connection to 50Ω

ΩΩ

Ω antenna

C2

22pF

C6

4.7nF

C5

33pF

R2

22K

C7

10nF

VDD

C1

22pF

R1

1M

X1

16 MHz

TRX_CE

1VSS 24

VSS 18

VDD 17

VSS

16

PWR_UP

2

uPCLK

3

VDD

4

VSS

5

CD

6

AM

7

DR

8

VSS

9

MISO

10

MOSI

11

SCK

12

XC2

15 XC1

14 CSN

13

VDD_PA 19

ANT1 20

ANT2 21

VSS 22

IREF 23

nRF905

VDD 25

VSS 26

VSS 27

VSS 28

VSS 29

VSS 30

DVDD_1V2 31

TXEN 32

U1

nRF905

VDD

L1

12nH

C3

180pF

C11

Optional

C12

6.8pF

L3

39nH

L2

39nH

C9

18pF

C10

18pF

C4

3.3nF

C8

33pF

VDD

C13

Optional

50 ohm RF I/O

TXEN

TRX_CE

PWR_UP

CD

AM

DR

SPI_MISO

SPI_MOSI

SPI_SCK

SPI_CSN

uPCLK

aaaaaaaa

Figure 15 433MHz operating nRF905 Application schematic, single ended connection

to 50Ω antenna by using a differential to single ended matching network.

Figure 16 868-915MHz operating nRF905 Application schematic, single ended

connection to 50Ω antenna by using a differential to single ended matching network.

It is recommended to add pull up or pull down resistors on signals that can enter a

floating state. For the nRF905 it is recommended to have pull up on the CSN signal

and pull down on the MOSI and SCK signal.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 35 of 42 June 2006

Component Description Size Value Tol. Units

C1 NP0 ceramic chip capacitor, (Crystal oscillator) 0603 22 ±5% pF

C2 NP0 ceramic chip capacitor, (Crystal oscillator) 0603 22 ±5% pF

C3 NP0 ceramic chip capacitor, (PA supply decoupling)

@ 433MHz

@ 868MHz

@ 915MHz

0603

180

33

±5% pF

C4 X7R ceramic chip capacitor, (PA supply decoupling) 0603 3.3 ±10% nF

C5 NP0 ceramic chip capacitor, (Supply decoupling) 0603 33 ±5% pF

C6 X7R ceramic chip capacitor, (Supply decoupling) 0603 4.7 ±10% nF

C7 X7R ceramic chip capacitor, (Supply decoupling) 0603 10 ±10% nF

C8 NP0 ceramic chip capacitor, (Supply decoupling) 0603 33 ±5% pF

C9 NP0 ceramic chip capacitor, (Impedance matching)

@ 433MHz

@ 868MHz

@ 915MHz

0603

18

5.6

±5%

<±0.25pF

pF

C10 NP0 ceramic chip capacitor, (Impedance matching)

@ 433MHz

@ 868MHz

@ 915MHz

0603

18

5.6

±5%

<±0.25pF

pF

C11 NP0 ceramic chip capacitor, (Impedance matching) 0603 Not fitted pF

C12 NP0 ceramic chip capacitor, (Impedance matching)

@ 433MHz

@ 868MHz

@ 915MHz

0603

6.8

22

±5%

pF

C13 NP0 ceramic chip capacitor, (Impedance matching)

@ 433MHz

@ 868MHz

@ 915MHz

0603

Not fitted

4.7

<±0.25pF

pF

L1 Chip inductor, (Impedance matching)

@ 433MHz: SRF> 433MHz

@ 868MHz: SRF> 868MHz

@ 915MHz: SRF> 915MHz

0603

12

±5% nH

L2 Chip inductor, (Impedance matching)

@ 433MHz: SRF> 433MHz

@ 868MHz: SRF> 868MHz

@ 915MHz: SRF> 915MHz

0603

39

10

±5%

nH

L3 Chip inductor, (Impedance matching)

@ 433MHz: SRF> 433MHz

@ 868MHz: SRF> 868MHz

@ 915MHz: SRF> 915MHz

0603

39

12

±5%

nH

R1 0.1W chip resistor, (Crystal oscillator bias) 0603 1 ±5% MΩ

R2 0.1W chip resistor, (Reference bias)

0603 22 ±1% kΩ

U1 nRF905 Transceiver QFN32L/5x5

X1 Crystal, C

L

= 12pF LxWxH =

4.0x2.5x0.8 16 ±30ppm MHz

Table 16 Recommended external components, single ended connection to 50Ω

antenna.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 36 of 42 June 2006

11.4 PCB Layout Example; Single Ended Connection to 50Ω

ΩΩ

Ω Antenna

Figure 17 shows a PCB layout example for the application schematic in Figure 15 and

Figure 18 shows a PCB layout example for the application schematic in Figure 16. A

double-sided FR-4 board of 1.6mm thickness is used. This PCB has a ground plane on

the bottom layer. Additionally, there are ground areas on the component side of the

board to ensure sufficient grounding of critical components. A large number of via

holes connect the top layer ground areas to the bottom layer ground plane.

a) Top silk screen

No components in bottom layer

b) Bottom silk screen

c) Top view

d) Bottom view

Figure 17 PCB layout example for 433MHz operation nRF905, single ended

connection to 50Ω antenna by using a differential to single ended matching network.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 37 of 42 June 2006

a) Top silk screen

No components in bottom layer

b) Bottom silk screen

c) Top view

d) Bottom view

Figure 18 PCB layout example for 868-915MHz operation nRF905, single ended

connection to 50Ω antenna by using a differential to single ended matching network.

A fully qualified RF-layout for the nRF905 and its surrounding components,

including antennas and matching networks, can be downloaded from

www.nordicsemi.no.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 38 of 42 June 2006

12 ABSOLUTE MAXIMUM RATINGS

Supply Voltages

VDD.............................. - 0.3V to + 3.6V

VSS.....................................................0V

Input Voltage

VI..........................- 0.3V to VDD + 0.3V

Output Voltage

VO.........................- 0.3V to VDD + 0.3V

Total Power Dissipation

PD (TA=85°C)................................200mW

Temperatures

Operating temperature ........................................... - 40°C to + 85°C

Storage temperature..............................................- 40°C to + 125°C

Note: Stress exceeding one or more of the limiting values may cause permanent

damage to the device.

ATTENTION!

Electrostatic sensitive device.

Observe precaution for handling.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 39 of 42 June 2006

13 GLOSSARY OF TERMS

Term Description

ADC Analog to Digital Converter

AM Address Match

CD Carrier Detect

CLK Clock

CRC Cyclic Redundancy Check

DR Data Ready

GFSK Gaussian Frequency Shift Keying

ISM Industrial-Scientific-Medical

kSPS kilo Samples per Second

MCU Micro Controller Unit

PWR_DWN Power Down

PWR_UP Power Up

RX Receive

SPI Serial Programmable Interface

CSN SPI Chip Select Not

MISO SPI Master In Slave Out

MOSI SPI Master Out Slave In

SCK SPI Serial Clock

SPS Samples per Second

STBY Standby

TRX_EN Transmit/Receive Enable

TX Transmit

TX_EN Transmit Enable

Table 17 Glossary of terms.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 40 of 42 June 2006

14 DEFINITIONS

Product Specification Identification Product Status Definition

Objective Product Specification Planned or Under Development. This specification contains

the design objectives for product development.

nRF: Specifications may change in any manner without

notice.

Preliminary Product Specification Engineering Samples and Pre Production series. This

specification contains preliminary data.

nRF: Nordic Semiconductor reserves the right to make

changes at any time without notice in order to improve design

and supply the best possible product.

Product Specification The product is qualified for production. Changes will be

notified according to industry standard criteria for

Product/Process Change Notifications.

Obsolete Product Specification Not In Production. This specification contains specifications

on a product that has been discontinued by Nordic

Semiconductor. The specification is printed for reference

information only.

Table 18 Product status definitions

Nordic Semiconductor ASA reserves the right to make changes without further notice

to the product to improve reliability, function or design. Nordic Semiconductor does

not assume any liability arising out of the application or use of any product or circuits

described herein.

LIFE SUPPORT APPLICATIONS

These products are not designed for use in life support appliances, devices, or systems

where malfunction of these products can reasonably be expected to result in personal

injury. Nordic Semiconductor ASA customers using or selling these products for use

in such applications do so at their own risk and agree to fully indemnify Nordic

Semiconductor ASA for any damages resulting from such improper use or sale.

Product specification revision date: 23.06.2006

Datasheet order code: 230606nRF905

written permission of the copyright holder.

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 41 of 42 June 2006

YOUR NOTES

PRODUCT SPECIFICATION

nRF905 Single Chip 433/868/915 MHz Radio Transceiver

Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone +4772898900 -Fax +4772898989

Revision: 1.4 Page 42 of 42 June 2006

Nordic Semiconductor ASA – World Wide Distributors

For Your nearest dealer, please see http://www.nordicsemi.no

Main Office:

Vestre Rosten 81, N-7075 Tiller, Norway

Phone: +47 72 89 89 00, Fax: +47 72 89 89 89

Visit the Nordic Semiconductor ASA website at http://www.nordicsemi.no