Functional description

AN1441

4/13

Doc ID 8422 Rev 2

Figure 4.

Test circuit

Note:

To take this measurement, the input capacitor is 100 µF instead of 1 µF. Typically, a 1 µF

input capacitor, like in the demonstration board circuit, is sufficient.

the short-circuit condition, the switch on the right side of Figure 4 was used.

1.3

Programming the current limit

The ST890 current limit can be programmed with the SET pin. This pin is internally

amplifier (Figure 1) which calculates the difference between the reference voltage and the

Figure 5.