L9779WD datasheet(72/170 Pages) STMICROELECTRONICS

No. de pieza	L9779WD

Descripción Electrónicos	Multifunction IC for engine management system

PDF	170 Pages

Scroll/Zoom	100%

Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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72 / 170 page

Functional description

L9779WD

72/170

DocID027452 Rev 5

Short circuit to battery

When the load is on, if the voltage of IGNx is bigger than the Vign_scb threshold for a time

longer than Tign_filt the SCB fault is detected and the output IGNx becomes high

impedance.

When the load is off, if the voltage of IGNx is bigger than the Vign_scb threshold for a time

longer than Tign_filt the SCB fault is detected and the output IGNx becomes high

impedance.

The SCB fault has a higher priority with respect to the OL fault.

According to the IGN_DIA_MODE bit, two behaviors are possible:

Latch mode

The fault is latched and is reset at every Read Diag operation.

The high impedance is removed and IGNx is driven by the command:

–

after a Read Diag operation

–

if the command is switched OFF and ON again.

No latch mode

The fault is not latched and if the voltage of IGNx is lower than the Vign_scb threshold

for a time longer than Tign_filt the fault state disappears and the high impedance is

removed.

L9779WD Datasheet(PDF) 72 Page - STMicroelectronics