SP40T datasheet(4/71 Pages) INFINEON

4 / 71 page

Data Sheet

Revision1.1

2020-05-14

SP40T

Tire Pressure Monitoring Sensor

Introduction

Measurements of pressure, acceleration, temperature, and battery voltage are performed under software

control, allowing the application software to format and prepare the data for RF transmission. An intelligent

system controller provides flexible wake-up capability in order to reduce energy usage. A calibrated Interval

Timer is included to permit periodic wake-up of the CPU, which in turn can then perform measurements and

transmit data to a receiver. The integrated Z-axis accelerometer may be used by the application software to

detect motion and distinguish between parking and driving situation.

The integrated microcontroller is instruction set compatible to the standard 8051 processor and is supported by

commercially available C compilers and IDE tool chains. The microcontroller core is supplemented with various

peripherals (e.g. hardware Manchester/BiPhase Encoder/Decoder, CRC Generator/Checker, I2C- and UART-

interface) that enable an easy implementation of TPMS application software.

For user specific application code the SP40T includes 12k of on-chip flash memory.

Another 2K of on-chip flash in a separated sector (extended code sector) is available, too. The main 12K code

sector can be erased independently from the extended sector which allows for boot-loader functionality.

The RF Transmitter block covers both 315 and 434 MHz UHF bands and supports FSK and ASK modulation. The

transmitter contains a fractional-N sigma-delta PLL synthesizer which allows for precise control of carrier

frequency and accurate FSK frequency modulation. A flexible baseband encoder and advanced power

management techniques are used to hold the peak current consumption during RF transmission to a minimum.

An integrated autonomous LF Receiver allows the SP40T to receive diagnostic or operating state commands,

supporting application features such as pressure-on-demand or tire position localization.

Finally, a comprehensive firmware library supports using all above mentioned hardware blocks effectively.

Especially a unique set of Angular Position Sensing (APS) functions allows calculating the instantaneous angular

position of the TPMS module relative to the car chassis which may be used for wheel localization on system level.

SP40T Datasheet(PDF) 4 Page - Infineon Technologies AG