Specifications

45
Wireless Connectivity Guide Texas Instruments 4Q 2014
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RFID
TMS37157
The PaLFI – Passive Low-Frequency
Interface TMS37157 enables short-
range two way communication
without the need of a battery by
harvesting the RF energy transmitted
from the base-station. It combines
a Low-Frequency RFID Transponder
with EEPROM memory and an SPI
Interface to connect to a microcon-
troller. The EEPROM memory is
accessible via the LF and SPI
interface without battery support. It
is ideal for data-logging applications
(configuration or updating a device
without the need of a battery), for
medical applications (non-battery
operated bio-sensors) and as a
method for recharging batteries while
enabling two way communications.
The TMS37157 can also be used in
combination with active low power
devices to wake up the active device
in a defined read zone and thus
conserve the battery life. Dependent
on system parameters such as
antenna sizes and base station power,
the device wirelessly powers an
MSP430 MCU at ranges up to
1.5 meter.
Key features
• Lowfrequencyhalfduplex(HDX)
interface
Special selective addressing
mode allows anti collision
Up to 8 kbit/s LF uplink data rate
• 3-wireSPIinterface
• 1008bitEEPROM:
968-bit free available EEPROM
user memory
32-bit unique serial number
8-bit selective address
Pages are irreversible lockable
and protectable
• Powermanagementforconnected
microcontroller
PaLFI – Passive Low-Frequency Interface Device
TMS37157
Get samples, evaluation modules and application notes at: www.ti.com/sc/device/TMS37157
PaLFI – Passive Low-Frequency Interface
Part number TMS37157
Communicationinterfaces SPI,RFID,directmicrocontrolleraccessviaRFID
Operatingfrequency 134.2kHz
Wiredcommunicationinterface 3-wireSPI
Operatingvoltage 2Vto3.6VDC
Currentconsumption Activemodemax150μA
Power-downmode60nA
Batterychargecurrent Max2mA
Memory 32-bituniqueserialnumber
968-bitEEPROMusermemory
8-bitselectiveaddress
Operatingtemperature –40˚Cto+85˚C
Storagetemperature –40˚Cto+125˚C
Package 16-pinVQFN(4mm×4mm)
Packing/delivery Tape-onreel,3,000perreel
TMS37157 block diagram.
Benefits
• Batterylessoperationofa
microcontroller supplied by RF field
• EEPROMmemoryexpansionfor
microcontroller
• DedicatedLFwake-up
• HDXtranspondercommunication
• Batterycheckandbatterycharge
function
Applications
• Wirelessbatterylessinterface
Medical
Metering
• LFwake-upforcontainertracking
• Configurationmemory(endof
production line)
Development tools and software
• ez430-TMS37157evaluationkit
Energy
LP data
Sensor systemBase station
TMS3705
LF Base Station
134, 2 kHz
Digital or Analog
Sensor
MSP430
PaLFI
TMS37157
LF Transponder
with EEPROM