Schematic design

AN3978

8/19

Doc ID 022179 Rev 1

A Transil™ diode is used to clamp high energy surge pulses followed by a capacitive filter to

suppress noise disturbance and limit application EMI. Capacitor C1 (100

μF) has a low ESR

parameter in order to effectively suppress supply voltage fluctuations.

1.4

Short-circuit current limit settings

Configuration of the current limit is done by the external resistor connection between the

RSC pin and GND. A 470

Ω resistor is used in the STEVAL-IFP020V1 application to adjust

the maximum current limit, which is 3.2 A (typ.), due to the fact that 0 < RSC < 5 k

Ω,

according to the L6370Q datasheet.

1.5

ON-DELAY configuration

ON-DELAY pin functionality is well described in the L6370Q datasheet. Basically, it is used

This feature also suppresses diagnostic activation in case of short-time overload or short-

circuit.

A capacitor value of 680 pF connected between the ON-DELAY and GND adjusts the

ON- DELAY time to: