Current limit circuit

AN4069

10/16

Doc ID 022926 Rev 1

6

Current limit circuit

The short-circuit current limit on the board is pre-programmed to the standard values (2.9 A

for the STEF05, 4.4 A for the STEF12), by means of a 22

Ω resistor placed on each

channel. The current limit values can be customized by changing the R1, R2 resistors

according to the desired peak current setting, as shown in the following charts.

Figure 8.

STEF05: current limit vs. R-limit

Figure 9.

STEF12: current limit vs. R-limit

6.00

V

5.00

ILIM

ISHORT

3.00

4.00

1.00

2.00

0.00

010

20

3040506070

80

Extern al Sense Resisto r (

Ω )

te a Se se Resistor (

Ω )

AM11051v1

V

9.00

7.00

8.00

400

5.00

6.00

ILIM

ISHORT

2.00

3.00

4.00

0.00

1.00

010

20

3040

506070

80

Et

l S

iR

i t

(

Ω )

Externa l Sens ing Resistor (

Ω )

AM11052v1