L9965P datasheet(42/104 Pages) STMICROELECTRONICS

Il numero della parte	L9965P

Spiegazioni elettronici	Automotive single channel pyro-fuse driver

PDF	104 Pages

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Produttore elettronici	STMICROELECTRONICS [STMicroelectronics]

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3.7.2.3

VRCM check

This step aims at diagnosing the voltage regulator/current monitor (VRCM) works properly.

This test requires HWSC (hardware self-check) prior to execution to cover possible faults determining VRCM is

out of range. To achieve safety targets, it is strongly recommended to apply such strategy before running this test.

Figure 20. VRCM test

VVRCM_REF

o_pf_pr_sel

RPYRO

PGND

IPR_PD

CESD

IPF_PU

The VRCM can be checked verifying the VRCM multiplexer connections to the PF or PR pins:

•

STB check:

–

The IPF_PU generator is connected to PF pin.

–

The VRCM is connected to PF pin.

–

If the VRCM works properly the VRCM_STB_FAIL flag remains zero.

•

STG check:

–

The IPR_PD generator is connected to PR pin.

–

The VRCM is connected to PR pin.

–

If the VRCM works properly the VRCM_STG_FAIL flag remains zero.

This test allows to check the ILEAK_SOURCE_TH and ILEAK_SINK_TH current thresholds.

The VRCM check diagnostic step duration is tVRCM_CHECK.

L9965P

Functional description

DS14702 - Rev 4

page 42/104

L9965P Scheda tecnica(PDF) 42 Page - STMicroelectronics