L9800 datasheet(38/55 Pages) STMICROELECTRONICS

номер детали	L9800

подробное описание детали	Automotive 8-channel LS driver

PDF	55 Pages

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производитель	STMICROELECTRONICS [STMicroelectronics]

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Limp-home mode

The limp is intended to handle limited functionality of the device in critical faulty situations.

A typical application scenario is reported in the Figure 28, with a system, which is reconfigured during the limp-

home as shown in the Figure 29. If the microcontroller that controls the device fails, an external safety

microcontroller takes over controlling parallel inputs IN0 and IN1. The SBC forces the IDLE signal low, which

brings the device in limp home. Once the switching activity on IN0, IN1 is over, being the IDLE pin still de-

asserted, the device reaches sleep mode.

During this mode active, the L9800 is only capable of driving two outputs that is, OUT2 through IN0 and OUT3

through IN1; such a mapping is fixed and overcomes an eventual different mapping programmed via SPI once the

limp-home is reached.

Figure 28. Possible system configuration during normal operating conditions

OUT1D

OUT2D

OUT3D

OUT4D

OUT5D

OUT6D

OUT7D

OUT0D

OUT07S

OUT56S

OUT34S

OUT12S

L9800

Limp-home mode

DS14041 - Rev 2

page 38/55

L9800 датащи(PDF) 38 Page - STMicroelectronics