L9788 datasheet(108/264 Pages) STMICROELECTRONICS

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High/low-side drivers - STARTER STR[1:3]

L9788

108/264

DS12308 Rev 4

In low-side configuration, if they are configured as starter CONFIG_REG3[4]=STR2_EN=1

and CONFIG_REG3[5]=STR3_EN=1, the driver STR2 and STR3 can work down to VB_IN

= 3.1 V. for THOLD.

In high-side configuration, if they are configured as starter CONFIG_REG3[4]=STR2_EN=1

and CONFIG_REG3[5]=STR3_EN=1, the driver STR2 and STR3 can work down to VB_IN

= 3.1 V for THOLD.

Furthermore, the driver can latch its ON state for THOLD even if the main microcontroller is

temporarily not working due to low-battery conditions.

HS/LS are intended to be used as starter relay driver. One for high-side, one for low-side.

STR2/3 should keep the status till VOFF_VB_IN.(3.1 V).

Each starter driver is separately put in on or off state by the MSC CONFIG-REG 14[5:7] just

for the time required to perform on or off diagnosis (Fast Diagnosis). At the end of the

diagnosis it is automatically put in the state determined by the current value of MSC data

frame.

The micro command is activated by writing 1 from 0 in the MSC registers (both for ON and

OFF).

8.1

ON state diagnosis

The ON state diagnosis has the same features as the low-side driver ON state diagnosis

described in chapter Section 7.1.1 and Section 7.1.2.

8.2

ON/OFF state - Error in on status diagnosis

Refer to paragraph Section 7.1.3.

8.3

OFF state diagnosis LS mode

The OFF state diagnosis in LS mode has the same features as the low-side driver OFF

state diagnosis described in paragraph Section 7.1.4.

8.4

OFF state diagnosis HS mode

The device provides off-state diagnostic for HS mode, simplified schematic of implemented

diagnostic is shown in Figure 41.

L9788 데이터시트(PDF) 108 Page - STMicroelectronics