Data Sheet

13

Rev. 1.2, 2014-05-09

SPI Driver for Enhanced Relay Control

SPIDER - TLE7233EM

Power Supply

5.1

Limp Home Mode

The TLE7233EM offers the capability of driving dedicated channels during eventual fail-safe operation of the

system. This limp home mode is activated by a high signal at pin LHI. In this mode, the SPI registers are reset and

the input pins are directly routed to their corresponding channels, see Table 3 for details.

Furthermore, the SPI is ignored and all input pins are referred to

V

if the digital supply or the microcontroller fail.

A high signal on LHI overrides a Reset signal on RST. In case of a limp home during sleep the device will therefore

wake up and enter the limp home mode.

During Limp home mode any SPI transmission will receive a TER flag.

After limp home operation all registers are reset and the device enters in sleep mode following low logic RST state,

or returns to ON state (all channels OFF with diagnostic currents active). Next SPI transmission will receive a TER

Flag.

Table 3

Routing during limp home mode

Input

controlled

Output

IN0

OUT0

IN1

OUT1

IN2

OUT2

IN3

OUT3