STEF12H60M datasheet(17/34 Pages) STMICROELECTRONICS

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During the startup, GOK is released once UVLO is reached, under the condition that Vout is below VDS_OK (drain

to source short detection, see Section 6.9 ), therefore it cannot be used directly as a Power Good flag. GOK is

also pulled to low level in the case of any of the faults described in Section 6.9 .

6.9

Diagnostic functions and protections

The STEF12H60M embeds several internal diagnostic features that prevent fault condition induced internally that

may affect the application (refer to Section 5 Electrical characteristics):

•

Power MOSFET gate leakage check during startup and normal operation (VGate-VIN < 5.6 V)

•

Gate shorted-to-VIN

•

Drain to source short in disabled mode (ON pin low). This protection prevents a new startup until the VOUT

falls below the VDS_Ok value.

•

VOUT too low (VOUT < 90% of VIN) after soft-start

•

VOUT does not reach 90% of VIN in 200 ms during startup

•

Charge pump error

•

Pull-down circuit error

In any case of fault, the GOK indicator is pulled down and the soft-start capacitor is discharged.

6.10

Latch (STEF12H60MPUR) and auto-retry versions (STEF12H60MAPUR)

The STEF12H60M electronic fuse is offered in two variants that differ in how the device reacts after a fault

condition (see Section 6.8 and Section 6.9 ). In particular, the STEF12H60MPUR latches off after a fault

and can be reset by pulling the VDD pin below the UVLO threshold or by re-cycling the supply voltage. The

STEF12H60MAPUR instead stays in OFF mode for 1 s. (TRetry) and after restarts automatically, initiating a

soft-start cycle. The number of restart cycles is not internally limited .

STEF12H60M

Diagnostic functions and protections

DS13608 - Rev 3

page 17/34

STEF12H60M Datasheet(PDF) 17 Page - STMicroelectronics