TRF7970A
SLOS743K – AUGUST 2011 – REVISED APRIL 2014
www.ti.com
The transmit system in passive target mode differs from active target and operates similar to the standard
tag. There is no automatic RF collision avoidance sequence, and encoders are used to code the data for
ISO14443A\B tag (at 106 kbps, to start) or FeliCa (at 212 kbps, to start) format. The collision avoidance
must be handled by the firmware on the connected MCU. The coding system adds all of the SOF, EOF,
CRC, parity bits, and synchronization bytes that are required by protocol. On the physical level, the
modulation of the initiator's RF field is done by changing the termination impedance of the antenna
between 4 Ω and open.
6.1.3.3
Card Emulation
The chip can enter this mode by setting appropriate option bits. There are two options to emulate a card.
For ISO14443A\B, the emulation supports 106-kbps data rate to start. For ISO14443A, the anticollision
algorithm can be performed using an internal state machine, which relieves the MCU of any real-time
tasks. The unique ID required for anticollision is provided by the MCU after wake-up of the system.
6.2
System Block Diagram
Figure 6-2 shows a block diagram of the TRF7970A.
VDD_I/O
RX_IN1
MUX
PHASE &
AMPLITUDE
DETECTOR
GAIN
RSSI
(AUX)
LOGIC
STATE
I/O_0
I/O_1
RF LEVEL
DETECTOR
CONTROL
LOGIC
I/O_2
RX_IN2
RSSI
(EXTERNAL)
[CONTROL
I/O_3
PHASE &
AMPLITUDE
GAIN
RSSI
(MAIN)
REGISTERS &
COMMAND
LOGIC]
I/O_4
I/O_5
VDD_PA
DETECTOR
FILTER
& AGC
DIGITIZER
MCU
INTERFACE
I/O_6
I/O_7
ISO
PROTOCOL
HANDLING
DECODER
IRQ
TX_OUT
TRANSMITTER ANALOG
FRONT END
FRAMING
BIT
FRAMING
127-BYTE
FIFO
SYS_CLK
DATA _CLK
SERIAL
VIN
VSS_PA
EN
EN2
ASK/OOK
MOD
OSC_IN
OSC_OUT
CONVERSION
CRC & PARITY
DIGITAL CONTROL
STATE MACHINE
VOLTAGE SUPPLY REGULATOR SYSTEMS
(SUPPLY REGULATORS AND REFERENCE VOLTAGES)
CRYSTAL OR OSCILLATOR
TIMING SYSTEM
Figure 6-2. System Block Diagram
VDD_A
BAND_GAP
VSS_A
VDD_RF
VSS_RF
VDD_X
VSS
VSS_D
6.3
Power Supplies
The TRF7970A positive supply input V IN (pin 2) sources three internal regulators with output voltages
V DD_RF , V DD_A and V DD_X . All regulators use external bypass capacitors for supply noise filtering and must
be connected as indicated in reference schematics. These regulators provide a high power supply reject
ratio (PSRR) as required for RFID reader systems. All regulators are supplied by V IN (pin 2).
The regulators are not independent and have common control bits in register 0x0B for output voltage
setting. The regulators can be configured to operate in either automatic or manual mode (register 0x0B,
bit 7). The automatic regulator setting mode ensures an optimal compromise between PSRR and the
highest possible supply voltage for RF output (to ensure maximum RF power output). The manual mode
allows the user to manually configure the regulator settings.
14
Detailed Description
Submit Documentation Feedback
Product Folder Links: TRF7970A
Copyright ? 2011–2014, Texas Instruments Incorporated
相关PDF资料
TRM-418-LT TRANSCEIVER RF 418MHZ LT SERIES
TRM-900-NT RF TXRX 915MHZ NT SERIES
TRX08GVP2540 TXRX OPT SCFF 8.5GB/S 850NM
TS-320240BRNO TCH PANEL 140X104 RESISTIVE MONO
TS-TFT3.5Z TOUCH PANEL 140X1.4.0 TFT
TS3-75B3 SENSOR THERMAL MOXIE NTC 75C
TSL26711FN IC PROXIMITY DETECTOR 6-DFN
TSOP57238TT1 IC IR RCVR MODULE 38KHZ
相关代理商/技术参数
TRF7970ARHBR 功能描述:IC RFID/NFC AFE 13.56MHZ 32QFN RoHS:是 类别:RF/IF 和 RFID >> RFID IC 系列:- 其它有关文件:CR14 View All Specifications 标准包装:1 系列:- RF 型:收发器 频率:13.56MHz 特点:ISO14443-B 封装/外壳:16-SOIC(0.154",3.90mm 宽) 供应商设备封装:16-SO 包装:Digi-Reel® 其它名称:497-5719-6
TRF7970ARHBT 功能描述:IC RFID/NFC AFE 13.56MHZ 32QFN RoHS:是 类别:RF/IF 和 RFID >> RFID IC 系列:- 其它有关文件:CR14 View All Specifications 标准包装:1 系列:- RF 型:收发器 频率:13.56MHz 特点:ISO14443-B 封装/外壳:16-SOIC(0.154",3.90mm 宽) 供应商设备封装:16-SO 包装:Digi-Reel® 其它名称:497-5719-6
TRF7970ATB 功能描述:RFID应答器 TRF7970A Target Brd RoHS:否 制造商:Murata 存储容量:512 bit 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体: 封装:Reel
TRF79A6AA17LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA18LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA19LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA20LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA21LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)