LD39100PUR datasheet(17/23 Pages) STMICROELECTRONICS

17 / 23 page

LD39100XX, LD39100XX12, LD39100XX25

Application information

Doc ID 15676 Rev 3

17/23

6.2

Enable function

The LD39100xx features an enable function. When the EN voltage is higher than 2 V, the

device is ON, and if it is lower than 0.8 V, the device is OFF. In shutdown mode, consumption

is lower than 1 µA.

The EN pin does not have an internal pull-up, which means that it cannot be left floating if it

is not used.

6.3

Power Good function

Most applications require a flag showing that the output voltage is in the correct range.

The Power Good threshold depends on the adjust voltage. When the adjust is higher than

0.92*VADJ, the Power Good (PG) pin goes to high impedance. If the adjust is below

0.80*VADJ the PG pin goes to low impedance. If the device is functioning well, the Power

Good pin is at high impedance. If the output voltage is fixed using an external or internal

resistor divider, the Power Good threshold is 0.92*VOUT.

The use of the Power Good function requires an external pull-up resistor, which must be

connected between the PG pin and VIN or VOUT. The typical current capability of the PG pin

is up to 6 mA. The use of a pull-up resistor for PG in the range of 100 k

Ω to 1 MΩ is

recommended. If the Power Good function is not used, the PG pin must remain floating.

LD39100PUR Datasheet(PDF) 17 Page - STMicroelectronics