The Infineon SP37 family of highly integrated TPMS tire pressure monitoring sensors are

suited for high volume TPMS applications. The TPMS ASIC integrates a low-power embedded

Microcontroller, LF receiver and Wireless FSK / ASK UHF Transmitter. With its highly

integrated mixed signal peripherals, the SP 37 requires only few external components to

complete TPMS module.

Main features:
· Supply voltage range from 1.9 V up to 3.6 V
· Operating temperature range -40 to +125 °C
· Low supply current
· Pressure sensor for 450 kPa or 900kPa range
· Z-axis acceleration sensor for motion detection
· Temperature sensor
· THERMAL SHUTDOWN mode for device protection at high temperatures
· Battery voltage sensor
· Integrated RF Transmitter for ISM Band 315/434 MHz
· Selectable output power 5 or 8 dBm (transformed into 50 Ohm load)
· Configurable RF transmission data rates up to 10 kbit/s Manchester coded (20

kchips/s)
· ASK/FSK modulation capability
· Frequency deviation up to 50 kHz in FSK mode
· Fully integrated VCO and PLL Synthesizer
· On chip crystal oscillator tuning
· LF Receiver with very high input sensitivity
· LF Receiver data rate 3.9 kbit/s
· 8051 instruction set compatible microcontroller (cycle-optimized)
· 6 kByte FLASH memory (for application code)
· 12 kByte ROM (for ROM library functions)
· 256 Bytes RAM
· Wakeup from POWER DOWN state using the Interval Timer, the LF Receiver or an

external wakeup source
connected via a GPIO pin
· I2C programming/debugging interface
· Hardware Manchester/BiPhase Encoder for RF Transmitter
· Hardware Manchester Decoder for LF Receiver
· 16Bit Hardware CRC generator
· 8Bit Pseudo Random Number Generator
· Watchdog timer
· 3 bidirectional GPIO pins