L7981 datasheet(14/44 Pages) STMICROELECTRONICS

Part #	L7981

Description	3 A step-down switching regulator

PDF	44 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

14 / 44 page

Functional description

L7981

14/44

Doc ID 15182 Rev 3

Figure 8.

Over current protection strategy

5.5

Enable function

The enable feature allows to put in stand-by mode the device.With EN pin lower than 0.3 V

the device is disabled and the power consumption is reduced to less than 30 µA. With EN

pin lower than 1.2 V, the device is enabled. If the EN pin is left floating, an internal pull down

ensures that the voltage at the pin reaches the inhibit threshold and the device is disabled.

The pin is also VCC compatible.

5.6

Hysteretic thermal shutdown

The thermal shutdown block generates a signal that turns off the power stage if the junction

temperature goes above 150°C. Once the junction temperature goes back to about 130°C,

the device restarts in normal operation. The sensing element is very close to the PDMOS

area, so ensuring an accurate and fast temperature detection.

L7981 Datasheet(PDF) 14 Page - STMicroelectronics