What is active clamping available with low-voltage IPDs?

When a low-side switch drives an inductive load, a high voltage is applied to the output terminal because of the back-EMF energy induced when the switch turns off. This back-EMF energy might degrade or damage the IPD.

Active clamping is a protective function to absorb the back-EMF energy incurred by the turn-off of the low-side switch. Active clamping also eliminates the need for freewheeling diodes (FWDs) that return back-EMF energy to a power supply.

Configuration of an  active clamping circuit
Figure 1 Configuration of an active clamping circuit
Operation of active clamping
Circuit
Active clamping period
開啟新視窗