Typical application

STEF12

10/20

Doc ID 019056 Rev 3

The contribution of the external capacitor to this time interval can be estimated by using the

following theoretical formula:

Equation 3

Figure 5.

5.4

Enable/Fault pin

The Enable/Fault pin has the dual function of controlling the output of the device and, at the

same time, of providing information about the device status to the application.

When it is used as a standard Enable pin, it should be connected to an external open-drain

or open-collector device. In this case, when it is pulled at low logic level, it turns the output of

the E-Fuse off.

If this pin is left floating, since it has internal pull-up circuitry, the output of the E-Fuse is kept

ON, in normal operating conditions.

In case of thermal fault, the pin is pulled to an intermediate state (Figure 6). This signal can

be provided to a monitor circuit, informing it that a thermal shutdown has occurred, or it can

be directly connected to the Enable/Fault pins of other STEFxx devices on the same

application in order to achieve a simultaneous enable/disable feature.

When a thermal fault occurs, the device can be reset either by cycling the supply voltage or

delay time

350

–

11.3

×

+

×

C

dvdt

×

=

AM09882v1

0

2

4

6

8

10

12

Time

En/Fault

VOUT

delay

time

ramp-up

time