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: [email protected] Please visit our website at www.ams.com Te ch ni ca am lc s on A te G nt st il lv al id Hardware Description of AS399x “LEO” - UHF RFID Reader System Demo Kit Reference Rev 0.3 Feb 2010 Proprietary and Confidential 1 Table of Contents: am lc s on A te G nt st il lv al id Introduction................................................................................................................ 3 Key Features............................................................................................................... 3 Short Description ....................................................................................................... 4 Hardware.................................................................................................................... 4 Port Definitions .......................................................................................................... 5 Detailed Description................................................................................................... 5 AS399X Pinout: ......................................................................................................... 6 C8051F340 Pin out..................................................................................................... 7 Power Connector ........................................................................................................ 7 USB Connector .......................................................................................................... 7 RS232 Connector ....................................................................................................... 7 Debugging Connector ................................................................................................ 7 Supply Concept .......................................................................................................... 8 Microcontroller Reset Circuit..................................................................................... 8 Oscillator Circuit ........................................................................................................ 9 VCO Concept. .......................................................................................................... 10 LED .......................................................................................................................... 10 Serial RS232 Interface ............................................................................................. 11 High Frequency RFID Output.................................................................................. 11 Decoupling and Antenna.......................................................................................... 11 Hardware Description UHF board ........................................................................... 12 LEO- Schematic ....................................................................................................... 12 Top mounted ............................................................................................................ 13 Top layer .................................................................................................................. 13 Bottom layer............................................................................................................. 13 Bill of Material ......................................................................................................... 14 Printed Circuit Board Instructions ........................................................................... 15 Attached files for PCB Production........................................................................... 15 Disclaimer ................................................................................................................ 16 Te ch ni ca 1 1.1 2 3 3.1 3.1.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 4 4.1 4.2 4.3 4.4 4.5 5 5.1 6 Proprietary and Confidential 2 1 Introduction al id 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. 1.1 am lc s on A te G nt st il lv 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. Key Features • • • • • Te ch ni ca 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 2 Short Description lv al id 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. 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. am lc s on A te G nt st il 3 Hardware Te ch ni ca 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 Pin P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 Detailed Description Signal IRQ TX RX SCLK Description Not used Not used Not used External Interrupt Input UART Transmit Pin UART Receive Pin Not used System Clock Input al id 3.1.1 Port Definitions lv 3.1 Signal IO0 IO1 IO2 IO3 IO4 IO5 IO6 IO7 Table 2: Port 1 Ctrl Ctrl Ctrl Ctrl Ctrl Ctrl Ctrl Ctrl Bit Bit Bit Bit Bit Bit Bit Bit Description Interface CLK Output Device Enable Output LED Output Not used Not used Not used Not used Not used ni Signal CLK EN LED - and and and and and and and and ch Pin P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 Description IO Data, Address IO Data, Address IO Data, Address IO Data, Address IO Data, Address IO Data, Address IO Data, Address IO Data, Address ca Pin P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 am lc s on A te G nt st il Table 1: Port 0 Te Table 3: Port 2 Proprietary and Confidential 5 Signal RESET Description Not used Not used Not used Not used Not used Not used Not used Output for resetting the MCU Pin 7 8 9 10 11 12 13 14 Signal GND D+ DVDD REGIN VBUS RST C2D am lc s on A te G nt st il Table 4: Port 4 lv Pin P4.0 P4.1 P4.2 P4.3 P4.4 P4.5 P4.6 P4.7 al id Note: Port 3 is not used. Description GND Pin USB Data + Signal USB Data - Signal VDD Pin Not used USB Power In Reset Pin Debugging Interface Table 5: Other uC Pins 3.2 AS399X Pinout: Te ch ni ca Pinout of AS399x Picture 2: AS399x Pinout Proprietary and Confidential 6 3.3 C8051F340 Pin out am lc s on A te G nt st il lv al id 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 RS232 Connector ni 3.6 ca 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. ch For debugging, the controller board has solder pads to connect an external RS232 circuit. Power for the external circuit is delivered through the connector. Debugging Connector Te 3.7 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 am lc s on A te G nt st il lv al id Silabs Debug Interface Picture 4: Schematic - Debug Interface 3.8 Supply Concept Te ch ni ca To filter out noise on the USB supply voltage a ferrite (L1) and two capacitors (C52, C53) are used. Additionally, each AS399X V DD 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 al id am lc s on A te G nt st il 3.10 Oscillator Circuit lv Picture 5: Reset Circuit Picture 6: Schematic - Oscillator Circuit Te ch ni ca 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. Proprietary and Confidential 9 3.11 VCO Concept. 915 MHz 1.2 mA charge pump current 50 kHz reference frequency Internal VCO VCO 20 MHz / V 20 MHz / V 20 MHz / V am lc s on A te G nt st il In following table, one can also find other settings for reference: lv • • • • al id 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: Reference Frequency [kHz] 50 50 100 Charge Pump Current [mA] C1 [pF] R1 [kΩ] C2 [nF] R2 [kΩ] C3 [pF] 1.2 0.6 1.2 220 120 150 27 56 27 3.3 1.5 1.8 56 110 47 110 56 68 Picture 7: Loop Filter Circuit Te ch ni ca Table 6: Loop Filter Reference Settings 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 3.13 Serial RS232 Interface For debugging an external RS232 interface may be used. 3.14 High Frequency RFID Output ca am lc s on A te G nt st il lv al id 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. ch ni Picture 8: Schematic - HF RFID Output Path 3.15 Decoupling Tx/Rx Te 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 4 Hardware Description UHF board LEO- Schematic Te ch ni ca am lc s on A te G nt st il lv al id 4.1 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 Top mounted 4.3 am lc s on A te G nt st il Picture 10: Assembly Top lv al id 4.2 Top layer Picture 11: Top Layer ca Bottom layer Te ch ni 4.4 Picture 12: Bottom Layer Proprietary and Confidential 13 Bill of Material 100n 100n 110p 100u U4 U1 QFN 64 9x9 AS3991-BQFT TQFP 48 Digikey: 336-1298-ND D1 0805 Digikey/160-1423-1-ND R1, R2, R4 R8 R3, R13 R5 R7, R14 R10 R11, R12 R15 R9 0603 0402 0603 0603 0402 0402 0603 0603 0402 Schukat / RL0603K001-1 Digikey/541-1.00LCT-ND Schukat/ RL0603E000 Schukat/ RL0603E820-1 Digikey/541-10.0k LCT -ND Digikey/541-6.80k LCT -ND Schukat/ RL0603E100-1 Digikey/541-51.0 HC T-ND Digikey/541-15.0k LCT -ND C1, C2 0603 C38, C50, C52 C25, C53 0402 0402 SMD-D C5,C8,C11,C14,C16;c24,C27,C34,C36, C40,C42,C43,C44,C45,C48 0402 C39,C41 SMD-B C12, C28 0603 C3 0603 2u2 220p 3n3 0402 0603 0402 C6, C7 C13,C29 C20,C21 C32, 0402 0603 0402 0402 ni 24p 4p7 47p 220p SMD inductor C4, C9, C10,C15, C17, C23,C26, C33, C37,C46,C47,C49,C55 C51 C30 ca 10n 10u 18p 1u 0603 39n TCML1-11 L3, L5 T1 0603 TCML1-11 LFCN-100D Ferrite Ferrite Mechanical components 20 MHZ crystal TSX-3225 Switch USB Connector MMC X Connector U6 L1 L1 1206 0805 TCD-13-4 U3 S1 J11 J1 3.2x2.5 SMD Type Te DigiKey/ PCC2277CT-ND DigiKey/ PCC2146CT-ND DigiKey/ PCC1718CT-ND Schukat/CTUF100U10D DigiKey/ PCC103BQCT-ND Schukat/CTUF010U20B DigiKey/ DigiKey/ PCC2174CT-ND DigiKey/ PCC2421CT-ND L2, L6 ch 3n3 Footprint am lc s on A te G nt st il Integrated Circuits (IC) AS3991 C8051F340 Other semiconductors LED SMD resistor 1k 0R 0R 820R 10k 27k 100R 51 56k SMD capacitors ordering information Reference al id Part Info lv 4.5 Proprietary and Confidential DigiKey/ 490-1435-1-ND DigiKey/ PCC1700CT-ND DigiKey/ 490-3219-1-ND DigiKey/ DigiKey/ PCC470CQCT-ND DigiKey/ 490-1303-1-ND 0 Würth 744 786 03 0 Würth 744 902 139 Municom Municom Digikey: 712-1120-1-ND Farnell:1515663 Municom KDS- TSX-3225 Farnell: 1201424 Buerklin:72F2280 Samtec:MMCX-J-P-H-ST-EM1 14 5.1 lv AS3990 UHF Board 90 x 30 mm milled FR4 Dielectric DE117 0.51 mm 2 am lc s on A te G nt st il Name Dimensions Edges PCB Material PCB Thickness Layer Count al id 5 Printed Circuit Board Instructions Attached files for PCB Production Format Gerber RS274x / Excellon Gerber files Top Side layer: Layer 01 Bottom Side Layer: Layer 04 Solder stop top Solder stop bottom Silk screen top AS3990_UHF_READER_PRINTER-17.top AS3990_UHF_READER_PRINTER-17.bot AS3990_UHF_READER_PRINTER-17.smt AS3990_UHF_READER_PRINTER-17.smb AS3990_UHF_READER_PRINTER-17.sst Drill files Thruhole Data for drills und holes thruhole.tap Material Thickness [µm] 36 (43 final thickness) ni Copper Plated ca PCB Layer Properties ch Pre Preg Te Copper Plated Layer Layer Name Comments *.top Top side Layer 1 500 36 (43 final *.bot thickness) Table 7: PCB Layer Properties Proprietary and Confidential DE117 Dielectric constant 4,7 Bottom side Layer 4 15 6 Disclaimer am lc s on A te G nt st il lv al id 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 ca Business Unit CNC Schloss Premstaetten A-8141 Unterpremstaetten AUSTRIA Tel: +43-(0)3136-500-5473 FAX: +43-(0)3136-500-4141 [email protected] Te ch ni Subject to change without notice Proprietary and Confidential 16