austriamicrosystems AG
is now
ams AG
The technical content of this austriamicrosystems application note is still valid.
Contact information:
Headquarters:
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
e-Mail: ams_sales@ams.com
Please visit our website at www.ams.com
Hardware Description of AS399x
“LEO” - UHF RFID Reader System
Demo Kit Reference
Rev 0.3 Feb 2010
Proprietary and Confidential 1
ams AG
Technical content still valid
Table of Contents:
1 Introduction................................................................................................................ 3
1.1 Key Features............................................................................................................... 3
2 Short Description ....................................................................................................... 4
3 Hardware.................................................................................................................... 4
3.1 Port Definitions .......................................................................................................... 5
3.1.1 Detailed Description................................................................................................... 5
3.2 AS399X Pinout: ......................................................................................................... 6
3.3 C8051F340 Pin out..................................................................................................... 7
3.4 Power Connector ........................................................................................................ 7
3.5 USB Connector .......................................................................................................... 7
3.6 RS232 Connector ....................................................................................................... 7
3.7 Debugging Connector ................................................................................................ 7
3.8 Supply Concept .......................................................................................................... 8
3.9 Microcontroller Reset Circuit..................................................................................... 8
3.10 Oscillator Circuit........................................................................................................ 9
3.11 VCO Concept. .......................................................................................................... 10
3.12 LED .......................................................................................................................... 10
3.13 Serial RS232 Interface ............................................................................................. 11
3.14 High Frequency RFID Output.................................................................................. 11
3.15 Decoupling and Antenna.......................................................................................... 11
4 Hardware Description UHF board........................................................................... 12
4.1 LEO- Schematic ....................................................................................................... 12
4.2 Top mounted ............................................................................................................ 13
4.3 Top layer .................................................................................................................. 13
4.4 Bottom layer............................................................................................................. 13
4.5 Bill of Material......................................................................................................... 14
5 Printed Circuit Board Instructions ........................................................................... 15
5.1 Attached files for PCB Production........................................................................... 15
6 Disclaimer ................................................................................................................ 16
Proprietary and Confidential 2
ams AG
Technical content still valid
1 Introduction
The AS399x UHF RFID Reader System Demo Kit supports the ISO 18000-6b and EPC
Generation 2 standards. The aim of the development kit is to demonstrate the performance
and the features of the AS399x UHF RFID reader chip and to enable customers to develop
their own application fast.
The AS399x UHF RFID Reader System is a single PCB solution offering two configurations:
• A UHF RFID reader stand alone operation aided by the on board microcontroller
• A direct access operation for development purposes with disabled MCU where the
host system directly controls the AS399x using a pin header interface. The operational
RF part can be used to develop customized software for controlling the AS399x. An
access to the IO pins for an external microcontroller is provided to speed up the design
phase of an UHF RFID reader application.
1.1 Key Features
• Reading and writing UHF RFID tags
• Communication with host computer using the USB interface
• USB HID device (automatically installed on host side)
• Low cost 8- bit micro controller is used
• Controller software written in C which can easily ported to a different
controller type.
• Host software (AS399x Reader Suite) written in C++ and MFC
• Only 300mA current consumption needed provided by standard USB ports.
• USB powered device
Proprietary and Confidential 3
ams AG
Technical content still valid
2 Short Description
The “LEO” UHF RFID Reader System is designed for short range tag detection and
is optimized regarding PCB area and power consumption. In order to minimize PCB
size no display or buttons (except Reset button) are used. To minimize costs no
special RF connectors are required. The connection to the antenna is established by a
MMCX connector.
designed for short range tag detection and
is optimized regarding PCB area and power consumption. In order to minimize PCB
size no display or buttons (except Reset button) are used. To minimize costs no
special RF connectors are required. The connection to the antenna is established by a
MMCX connector.
For powering up the UHF RFID Reader System and for the communication with the
host system the USB interface is used. After power up the internal registers of the
reader chip are configured with default values which enables the reader system to be
functional right from the beginning.
For powering up the UHF RFID Reader System and for the communication with the
host system the USB interface is used. After power up the internal registers of the
reader chip are configured with default values which enables the reader system to be
functional right from the beginning.
3 Hardware 3 Hardware
For the RF communication with the tags the AS399x UHF RFID reader chip is used
and a Silabs C8051F340 serves as controller. A description of the API can be found in
the application note “AN399x LEO API Description”.
For the RF communication with the tags the AS399x UHF RFID reader chip is used
and a Silabs C8051F340 serves as controller. A description of the API can be found in
the application note “AN399x LEO API Description”.
Picture 1: Dimensions of PCB
Proprietary and Confidential 4
ams AG
Technical content still valid
3.1 Port Definitions
3.1.1 Detailed Description
Pin Signal Description
P0.0 - Not used
P0.1 - Not used
P0.2 - Not used
P0.3 IRQ External Interrupt Input
P0.4 TX UART Transmit Pin
P0.5 RX UART Receive Pin
P0.6 - Not used
P0.7 SCLK System Clock Input
Table 1: Port 0
Pin Signal Description
P1.0 IO0 IO Data, Address and Ctrl Bit
P1.1 IO1 IO Data, Address and Ctrl Bit
P1.2 IO2 IO Data, Address and Ctrl Bit
P1.3 IO3 IO Data, Address and Ctrl Bit
P1.4 IO4 IO Data, Address and Ctrl Bit
P1.5 IO5 IO Data, Address and Ctrl Bit
P1.6 IO6 IO Data, Address and Ctrl Bit
P1.7 IO7 IO Data, Address and Ctrl Bit
Table 2: Port 1
Pin Signal Description
P2.0 CLK Interface CLK Output
P2.1 EN Device Enable Output
P2.2 LED LED Output
P2.3 - Not used
P2.4 - Not used
P2.5 - Not used
P2.6 - Not used
P2.7 - Not used
Table 3: Port 2
Proprietary and Confidential 5
ams AG
Technical content still valid
Note: Port 3 is not used.
Pin Signal Description
P4.0 - Not used
P4.1 - Not used
P4.2 - Not used
P4.3 - Not used
P4.4 - Not used
P4.5 - Not used
P4.6 - Not used
P4.7 RESET Output for resetting the MCU
Table 4: Port 4
Pin Signal Description
7 GND GND Pin
8 D+ USB Data + Signal
9 D- USB Data - Signal
10 VDD VDD Pin
11 REGIN Not used
12 VBUS USB Power In
13 RST Reset Pin
14 C2D Debugging Interface
Table 5: Other uC Pins
3.2 AS399X Pinout:
Pinout of AS399x
Picture 2: AS399x Pinout
Proprietary and Confidential 6
ams AG
Technical content still valid
3.3 C8051F340 Pin out
The pinout from Silabs microcontroller C8051F340 is shown below.
Picture
3
: C8051F340 Pin out
[
Silabs 2006
]
3.4 Power Connector
No separate power connector is needed. Power is supplied through the USB
connector.
3.5 USB Connector
USB is used for communication with the host and power supply. No external matching and
pull down resistors are needed, since all parts are integrated in the microcontroller.
3.6 RS232 Connector
For debugging, the controller board has solder pads to connect an external RS232
circuit. Power for the external circuit is delivered through the connector.
3.7 Debugging Connector
In the following picture a special interface is highlighted which is used to directly connect the
Silabs USB Debug Adapter. The circuit is taken from the Silabs Development Kit data sheet
[SilabsDK 2006].
The resistor R3 can be used to supply the board via the debugging connector.
Proprietary and Confidential 7
ams AG
Technical content still valid
Silabs Debug
Interface
Picture 4: Schematic - Debug Interface
3.8 Supply Concept
To filter out noise on the USB supply voltage a ferrite (L1) and two capacitors (C52,
C53) are used. Additionally, each AS399X VDD pin is featured with two capacitors
(10 nF & 2.2 µF). The microcontroller supply VDD (pin 10) only needs one 100nF
capacitor (C1).
During power down mode the majority of the AS399x reader chip is switched off but
still generates a 3.3V supply voltage (VDD_D = pin 38) which supplies the
microcontroller unit (MCU). This mode is configured by the resistor R7 (10kΩ) at
OAD2 (pin 30) to GND. After start up the microcontroller has to pull the AS399X
enable pin (EN = pin 39) to high in order to start the operation of the AS399X
finalizing the power up sequence.
3.9 Microcontroller Reset Circuit
The reset circuit needs only two capacitors (C2, C3) for power on reset. A pull- up
resistor (R1), a series resistor (R2) and a push button (S1) for resetting during normal
operation is used (see Picture 5). To enable a reset trough the software, resistor R4 is
connected between port pin P4.7 and the reset pin (/RST = pin 13). If the
microcontroller needs to be reset, the software has to write a logic zero to P4.7.
Proprietary and Confidential 8
ams AG
Technical content still valid
Picture 5: Reset Circuit
3.10 Oscillator Circuit
The AS399X can be used with a conventional quartz crystal or a TCXO. The crystal should
have an accuracy of 10ppm. Most crystals do not provide this high accuracy for this reason a
TCXO is recommended. Besides good frequency stability a TCXO inherently provides better
temperature stability.
Picture 6: Schematic - Oscillator Circuit
Proprietary and Confidential 9
ams AG
Technical content still valid
3.11 VCO Concept.
To generate the high frequency carrier signal for the communication with the tag (840 MHz –
960 MHz) the internal VCO is used and thus only a few passive components are needed. The
external loop filter components need to be calculated for each parameter set of loop filter
current, reference frequency and charge pump current. For this particular reference design
following settings were used:
• 915 MHz
• 1.2 mA charge pump current
• 50 kHz reference frequency
• Internal VCO
In following table, one can also find other settings for reference:
VCO
Reference
Frequency
[kHz]
Charge Pump
Current [mA]
C1
[pF]
R1
[kΩ]
C2
[nF]
R2
[kΩ]
C3
[pF]
20 MHz / V 50 1.2 220 27 3.3 56 110
20 MHz / V 50 0.6 120 56 1.5 110 56
20 MHz / V 100 1.2 150 27 1.8 47 68
Table 6: Loop Filter Reference Settings
Picture 7: Loop Filter Circuit
3.12 LED
For an easy and fast functional check, an external LED with a current limitation resistor is
included. During normal operation, the LED is continuously flashing.
Proprietary and Confidential 10
ams AG
Technical content still valid
3.13 Serial RS232 Interface
For debugging an external RS232 interface may be used.
3.14 High Frequency RFID Output
The 20 dBm main differential outputs are used. The differential outputs need to be
converted to single- ended outputs. This is done by a Balun (Balanced/ Unbalanced)
XFMR_TCML1-11 from Mini-Circuits®.
The low pass filter (U6) is used to filter out second and higher order harmonics
generated by the PA and the high pass filter (U5) can be used to shortcut the second
harmonic. This high pass filter is optional.
Picture 8: Schematic - HF RFID Output Path
3.15 Decoupling Tx/Rx
To separate transmit and receive path a directional coupler is used. Between the power
amplifier and directional coupler respectively between the directional coupler and the input
pin (Mixs_in) in the receive path, π- networks may be inserted. These networks are used for
matching but are normally not required.
Proprietary and Confidential 11
ams AG
Technical content still valid
4 Hardware Description UHF board
4.1 LEO- Schematic
Picture 9: LEO Schematic
Note that the component values in the schematic may have been changed. Please review the
current BOM for the latest status.
Proprietary and Confidential 12
ams AG
Technical content still valid
4.2 Top mounted
Picture 10: Assembly Top
4.3 Top layer
Picture 11: Top Layer
4.4 Bottom layer
Picture 12: Bottom Layer
Proprietary and Confidential 13
ams AG
Technical content still valid
4.5 Bill of Material
Part Info Reference Footprint ordering information
I n tegra ted Circu its (IC)
AS3991 U4 QFN 64 9x9 AS3991-BQFT
C8051F340 U1 TQFP 48 Digikey: 336- 1298-ND
Other semiconductors
LED D1 0805 Digikey/160-1423-1-ND
SMD resistor
1k R1, R2, R4 0603 Schukat / RL0603K001-1
0R R8 0402 Digikey/541-1.00LCT-ND
0R R3, R13 0603 Schukat/ RL0603E000
820R R5 0603 Schukat/ RL0603E820-1
10k R7, R14 0402 Digikey/541-10.0k LCT-ND
27k R10 0402 Digikey/541-6.80k LCT-ND
100R R11, R12 0603 Schukat/ RL0603E100-1
51 R15 0603 Digikey/541-51.0 HCT-ND
56k R9 0402 Digikey/541-15.0k LCT-ND
100n C1, C2 0603 DigiK ey/ PCC2 277CT-ND
100n C38, C50, C52 0402 DigiKey/ PCC2 146CT-ND
110p C25, 0402 Di giK ey/ PCC1 718CT-ND
100u C53 SMD-D Schukat/CTUF100U10D
10n C5,C8,C11,C14,C16;c24,C27,C34,C36,
C40,C42,C43,C44,C45,C48 0402 DigiKey/ PCC1 03BQCT-ND
10u C39,C41 SMD-B Schukat/CTUF010U20B
18p C12, C28 0603 Di
g
iKe
y
/
1u C3 0603 DigiKey/ PCC2174CT-ND
2u2 C4, C9, C10,C15, C17, C23,C26, C33,
C37,C46,C47,C49,C55 0402 DigiKey/ PCC2 421CT-ND
220p C51 0603 Di
g
iKe
y
/ 490-14 35-1-ND
3n3 C30 0402 Di giK ey/ PCC1 700CT-ND
24p C6, C7 0402 Di giK ey/ 490-32 19- 1-ND
4
p
7C13,C29 0603 Di
g
iKe
y
/
47
p
C20,C21 0402 Di
g
iKe
y
/ PCC4 70CQ CT-ND
220p C32, 0402 Di
g
iKe
y
/ 490-13 03-1-ND
0
Würth 744 786 03
0
Würth 744 902 139
TCML1-11 T1 TCML1-11 Municom
Municom
Digikey: 712- 1120-1-ND
Ferrite L1 0805 Farnell:1515663
Ferrite L1 TCD-13-4 Municom
20 MHZ crystal TSX-3225 U3 3.2x2.5 KDS- TSX-3225
Swi tch S1 SMD Type Farne ll: 1201 424
USB Connector J11 Buerklin:72F2280
MMCX Connector J1 Samtec:MMC X-J-P-H-ST -EM1
0603
0603
1206
3n3 L2, L6
U6
L3, L5
LFCN-100D
39n
SMD capacitors
SMD inductor
Mechan ical co mpo nents
Proprietary and Confidential 14
ams AG
Technical content still valid
5 Printed Circuit Board Instructions
Name AS3990 UHF Board
Dimensions 90 x 30 mm
Edges milled
PCB Material FR4 Dielectric DE117
PCB Thickness 0.51 mm
Layer Count 2
5.1 Attached files for PCB Production
Format Gerber RS274x / Excellon
Gerber files
Top Side layer: Layer 01 AS3990_UHF_READER_PRINTER-17.top
Bottom Side Layer: Layer 04 AS3990_UHF_READER_PRINTER-17.bot
Solder stop top AS3990_UHF_READER_PRINTER-17.smt
Solder stop bottom AS3990_UHF_READER_PRINTER-17.smb
Silk screen top AS3990_UHF_READER_PRINTER-17.sst
Drill files Data for drills und holes
Thruhole thruhole.tap
PCB Layer Properties
Material Thickness [µm] Layer Layer
Name Comments
Copper
Plated
36 (43 final
thickness) *.top Top side Layer 1
DE117 Dielectric
constant 4,7
Pre Preg 500
Copper
Plated
36 (43 final
thickness) *.bot Bottom side Layer 4
Table 7: PCB Layer Properties
Proprietary and Confidential 15
ams AG
Technical content still valid
Proprietary and Confidential 16
6 Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent identification
provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express,
statutory, implied, or by description regarding the information set forth herein or regarding the freedom
of the described devices from patent infringement. austriamicrosystems AG reserves the right to
change specifications and prices at any time and without notice. Therefore, prior to designing this
product into a system, it is necessary to check with austriamicrosystems AG for current information.
This product is intended for use in normal commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or high reliability applications, such as
military, medical life-support or life-sustaining equipment are specifically not recommended without
additional processing by austriamicrosystems AG for each application.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate.
However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages,
including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of
business or indirect, special, incidental or consequential damages, of any kind, in connection with or
arising out of the furnishing, performance or use of the technical data herein. No obligation or liability
to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical
or other services.
Copyright © 2010, austriamicrosystems AG,
Schloss Premstaetten, 8141 Unterpremstaetten, Austria.
For further information please contact
Business Unit CNC
Schloss Premstaetten
A-8141 Unterpremstaetten
AUSTRIA
Tel: +43-(0)3136-500-5473
FAX: +43-(0)3136-500-4141
wireless@austriamicrosystems.com
Subject to change without notice
ams AG
Technical content still valid
