designed for automotive restraint applications. The device, located in the eCU

(electronic Control Unit) of the airbag system, is able to receive data from different

types of intelligent sensors like inertia and pressure sensor satellites for front-,

side-, or rear-crash sensor applications. It provides a pre-regulated power supply

voltage to the satellites over a twisted pair of wires. The satellite module transmits

digital data to TLe 7729 by modulating the line current.

Applications

Automotive Restraint Applications

Features

4 independent satellite receiver channels for current modulated data

each channel can support up to two satellites with

a total of up to eight sensors

Data rate 125 kBaud

Support of 11-, 13-, 18-Bit Manchester 1 or 2 encoded messages

Channel configuration in pairs (Bus Mode, Protocol Type)

Supply of satellite channels via 4 independent voltage regulators

Adjustable current level detection thresholds

Asynchronous and synchronous data transmission modes

All digital I/Os are 3.3 V and 5 V compatible

4 Digital outputs for voltage-converted received satellite signals

16-bit 8 Mhz Serial Peripheral Interface (SPI)

embedded protocol handler for data preprocessing

Small P-TSSOP-28 Package

Embedded Protection Functions

Current limitation in case of satellite output shorted to GND or Battery

Channel specific over-temperature shutdown

■

■

■

■

■

■

■

■

■

■

■

■

■

■

■

■

w w w . i n f i n e o n . c o m / r e s t r a i n t - s y s t e m - I C

Automotive Power

Product Brief

TLE 7729

4 Channel Airbag Satellite Receiver IC

Power Supply

&

Control

Protocol

Handler

&

Control

Logic

SATFD1 - Driver

SATFD 2 - Driver

6

23

SATFD1

SATREF12

27

28

Sense

&

Control

Logic

6 V/11 V

15

1

14

22

SATREF34

20

SATFD2 2

SATFD 3 - Driver

SATFD3 13

SATFD 4 - Driver

Protocol Handler

SATFD4

AGND

Start

Bits

CRC

Sensor

Status

Sensor Data

16

21

DGND

7

N.C.

26

N.C.

HW Status

Communication Status

17

TLE 7729

N.C.

3

TEST

12

RIN

24

CLK

8

SATSYNC

18

RxD3

11

RxD2

4

RxD1

25

SPI

Interface

MOSI

9

CS

19

SCK

10

MISO

5

Channel

Address

P

System

Status

Receiver Data

Embedded Diagnostic Functions

Leakage detection to GND and Battery

Ground loss detection

Short to GND and open detection at every

reference pins

■

■

■