A current limit can be programmed using an external resistor connected from the IL pin to GND. This programmed current limit (±20% accurate) refers to the continuous current through the device and therefore, when operated at its maximum current rating (6 A), the programmed current limit needs to be set 20% higher. As shown in Figure 8-2, a current limit event of this nature is defined as a soft short. The resistor value R_IL, can be calculated using Equation 7 for VIN ≤ 3 V, and Equation 8 for VIN > 3 V, where I_L is the programmed current limit value in amperes. This programmable current limiting feature is different from the internal current limiting activated during fast trip mode as shown in Figure 8-3. A current limit event in this case is defined as a hard short and this current limit (typical of 22 A) cannot be programmed.

Equation 7.

for VIN ≤ 3 V

Equation 8.

for VIN > 3 V