L6983 datasheet(24/63 Pages) STMICROELECTRONICS

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Figure 21. Over current procedure with persistent short circuit between VOUT and GND

6.9

Thermal shutdown

The shutdown block disables the switching activity if the junction temperature is higher than a fixed internal

threshold (TSHDWN refer to Table 6. Electrical characteristics). The thermal sensing element is close to the power

elements, assuring fast and accurate temperature detection. A hysteresis of approximately 30 °C prevents the

device from turning ON and OFF too fast. After a thermal protection event is expired, the L6983 restarts with a

new soft-start.

6.10

Power Good

The PGOOD pin indicates whether the output voltage is within its regulation level. The pin output is an open drain

MOSFET. The PG is pulled low when:

The FB pin voltage is lower than 90% (typ.) of the nominal internal reference for more than 10 µs

The FB pin voltage is higher than 120% (typ.) of the nominal internal reference for more than 10 µs (see

Section 6.7 Overvoltage protection)

During the soft-start procedure also with pre-charged VOUT

If a thermal shutdown event occurs

If a UVLO event occurs

The PG pin is VIN compatible.

L6983

Thermal shutdown

DS13116 - Rev 1

page 24/63

L6983 数据表(PDF) 24 Page - STMicroelectronics