MICRF103BMTR - Micrel - Product.Network

June 2002 1 MICRF103

MICRF103 Micrel

MICRF103

QwikRadio™ UHF ASK Transmitter

Final

General Description

The MICRF103 is a single chip Transmitter IC for remote

wireless applications. The device employs Micrel’s latest

QwikRadio™ technology. This device is a true ”data-in,

antenna-out” monolithic device. All antenna tuning is accom-

plished automatically within the IC which eliminates manual

tuning, and reduces production costs. The result is a highly

reliable yet extremely low cost solution for high volume

wireless applications. Because the MICRF103 is a true

single-chip radio transmitter, it is easy to apply, minimizing

design and production costs, and improving time to market.

The MICRF103 uses a novel architecture where the external

antenna is tuned by the internal UHF synthesizer. This

transmitter is designed to comply worldwide UHF unlicensed

band international radio regulations. The IC is compatible

with virtually all ASK/OOK (Amplitude Shift Keying/On-Off

Keyed) UHF receiver types from wide-band super-regenera-

tive radios to narrow-band, high performance super-hetero-

dyne receivers. The transmitter is designed to work with

transmitter data rates up to 115k bits per second.

The automatic tuning in conjunction with an external resistor,

insures that the transmitter output power stays constant at

maximum regulatory transmit power limits for the life of the

battery.

When coupled with Micrel’s family of QwikRadio™ receivers,

the MICRF103 provides the lowest cost and most reliable

remote actuator and RF link system available.

Typical Application

VDD

VSS

REFOSC

ASK

MICRF103

Note: Example for 868MHz

ASK DATA INPUT

RP2

6.8k

0.1µF

4.7µF

RP1

100k

+5V

8.2pF

100pF

1.0pF

10nH

1.0pF

27nH

ANTP

ANTM

STBY

100k

SAW Filter 50Ω

Monopole

PCB Antenna

Figure 1

Features

•Complete UHF transmitter on a monolithic chip

•Frequency range 800MHz to 1GHz

•Data rates to 115kbps

•Automatic antenna alignment, no manual adjustment

•Low external part count

•Low standby current <1µA

Applications

•Remote keyless entry systems (RKE)

•Remote fan/light control

•Garage door opener transmitters

•Remote sensor data links

Ordering Information

Part Number Temperature Range Package

MICRF103BM –40°C to +85°C 8-Pin SOIC

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

QwikRadio is a trademark of Micrel, Inc. The QwikRadio ICs were developed under a partnership agreement with AIT of Orlando, Florida.

MICRF103 Micrel

MICRF103 2 June 2002

Pin Description

Pin Number Pin Name Pin Function

1 PC Power Control Input. The voltage at this pin should be set between 0.1V to

0.4V for normal operation.

2 VDD Positive power supply input for the IC.

3 VSS This pin is the ground return for the IC. A power supply bypass capacitor

connected from VDD to VSS should have the shortest possible path.

4 REFOSC This is the timing reference frequency which is the transmit frequency

divided by 64. Connect a crystal (mode dependent) between this pin and

VSS, or drive the input with an AC coupled 0.5Vpp input clock. See

Refer-

ence Oscillator

section in this data sheet under

Electrical Characteristics.

5 STBY Input for transmitter stand-by control pin is pulled to VDD for transmit

operation and VSS for stand-by mode.

6 ANTM Negative RF power output to drive one side of the transmit antenna.

7 ANTP Positive RF power output to drive the other side of the transmit antenna.

8 ASK Amplitude Shift Key modulation data input pin. For CW operation, connect

this pin to VDD.

Pin Configuration

1PC

VDD

VSS

REFOSC

8 ASK

ANTP

ANTM

STBY

MICRF103BM

June 2002 3 MICRF103

MICRF103 Micrel

Electrical Characteristics

Specifications apply for 4.75V < VDD < 5.5V, VPC = 0.35V, TA = 25°C, freqREFOSC = 13.5625MHz, STBY = VDD. Bold values indicate

–40°C ≤ TA ≤ 85°C unless otherwise noted.

Parameter Condition Min Typ Max Units

Power Supply

Standby Supply Current, IQVSTBY < 0.5V 0.10 µA

MARK Supply Current, ION @868MHz 19 26.5 mA

@915MHz 20 27.5 mA

SPACE Supply Current, IOFF @868MHz 14 18 mA

@915MHz 15 21 mA

MARK/SPACE Ratio 33%@868MHz 16 mA

33%@915MHz 17 mA

RF Output Section and Modulation Limits:

Maximum Power Level, POUT @868MHz (EIRP) -3 dBm

@915MHz (EIRP) -3 dBm

Output Power Variation over supply and temperature ±2 dBm

Extinction ratio for ASK 38 45 dBc

Varactor tuning range Note 5 2.6 3.0 3.3 pF

Reference Oscillator Section

Reference Oscillator Input 300 kΩ

Impedance

Reference Oscillator Source 5.0 µA

Current

Reference Oscillator Input 0.2 1.0 VPP

Voltage (peak-to-peak)

Digital / Control Section

Calibration Time note 7, ASK=HIGH 20 ms

Power Amplifier Output Hold-off note 4, STDBY transition from LOW to HIGH 5 ms

Time from STBY crystal, ESR < 20Ω

Transmitter Stabilization Time from external reference (500mVpp) 9 ms

From STBY crystal, ESR < 20Ω12 ms

Maximum Data rate

- ASK modulation duty cycle of the modulating signal = 50% 115 kbits/s

STBY HIGH VIH enable voltage 0.8VDD V

STBY LOW VIL 0.1VDD

ASK Pin VIH, input high voltage 0.8VDD V

VIL, input low voltage 0.1VDD V

ASK Input Current ASK = 0V, 5.0V input current –10 0.1 10 µA

Absolute Maximum Ratings (Note 1)

Supply Voltage(VDD) .....................................................+6V

Voltage on I/O Pins ............................. VSS–0.3 to VDD+0.3

Storage Temperature Range ...................-65°C to + 150°C

Lead Temperature (soldering, 10 seconds) ........... + 300°C

ESD Rating, Note 3

Operating Ratings (Note 2)

Supply Voltage (VDD) .................................... 4.75V to 5.5V

Maximum Supply Ripple Voltage ...............................10mV

PC Input Range......................................0.1V < VPC < 0.4V

Ambient Operating Temperature (TA) ........ –40°C to +85°C

Programmable Transmitter Frequency Range:

........................................................ 800MHz to 1GHz

MICRF103 Micrel

MICRF103 4 June 2002

Note 1. Exceeding the absolute maximum rating may damage the device.

Note 2. The device is not guaranteed to function outside its operating rating.

Note 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.

Note 4. After the release of the STDBY, the device requires an initialization time to settle the REFOSC and the internal PLL. The first MARK state

(ASK HIGH) after exit from STDBY needs to be longer than the initialization time. The subsequent low to high transitions will be treated as

data modulation whereby the envelope transition time will apply.

Note 5. The varactor capacitance tuning range indicates the allowable external antenna component variation to maintain tune over normal production

tolerances of external components. Guaranteed by design not tested in production.

Note 6. For the ASK modulation scheme, the part will accept ASK (digital ON/OFF) input and will transmit the data with a finite extinction ratio and the

pin will set the MARK power level.

Note 7. When the device is first powered up or it loses power momentarily, it goes into the calibration mode to tune up the transmit antenna.

Test Circuit

VDD

VSS

REFOSC ASK

MICRF103

ANTM

ANTP

STBY

100Ω4:1

680pF

7.1nH

680pF

200Ω

100Ω

50Ω

June 2002 5 MICRF103

MICRF103 Micrel

Typical Characteristics

-50

-40

-30

-20

-10

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

MARK POUT (dBm)

VPC (V)

Output Power

vs. PC Pin Volta

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

MARK ION (mA)

VPC (V)

Mark Current

vs. PC Volta

MICRF103 Micrel

MICRF103 6 June 2002

Functional Description

The block diagram illustrates the basic structure of the

MICRF103. Identified in the figure are the principal functional

blocks of the IC, namely the (1, 2, 3, 4, 5) UHF synthesizer,

(6a/b) Buffer, (7) Antenna tuner, (8) Power amplifier, (9) TX

bias control, (10) Reference bias and (11) Process tuner.

The UHF synthesizer generates the carrier frequency with

quadrature outputs. The in-phase signal (I) is used to drive

the PA and the quadrature signal (Q) is used to compare the

antenna signal phase for antenna tuning purpose.

The antenna tuner block senses the phase of the transmit

signal at the antenna port and controls the varactor capacitor

to tune the antenna.

The power control unit senses the antenna signal and con-

trols the PA bias current to regulate the antenna signal to the

transmit power.

Functional Diagram

Bias

Control

Varactor

Device

Antenna

Tuning

Control

Power

Amp

Buffer

VSS

ANTM

ANTP

ASK

Buffer

Prescaler

÷64

REF.OSC

VDD

(10)

(5)

(2)

Reference

Oscillator (1)

VCO (4)

(3)

(9) (8)

(7)

(11)

(6a)

(6b)

STBY Reference

Bias

Phase

Detector

Figure 2. MICRF103 Block Diagram

The process tune circuit generates process independent bias

currents for different blocks.

Included within the IC is a differential varactor that serves as

the tuning element to insure that the transmit frequency and

antenna are aligned with the receiver over all supply and

temperature variations.

June 2002 7 MICRF103

MICRF103 Micrel

Package Information

45°3°–6°

0.244 (6.20)

0.228 (5.80)

0.197 (5.0)

0.189 (4.8)

0.063 (1.60) MAX

SEATING

PLANE

0.026 (0.65)

MAX)

0.016 (0.40)

TYP

0.154 (3.90)

0.057 (1.45)

0.049 (1.25)

0.193 (4.90)

0.050 (1.27)

TYP

PIN 1

DIMENSIONS:

INCHES (MM)

8-Pin SOP (M)

MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA

TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com

This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or

other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel, Inc.