Functional description

L9935

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Doc ID 5198 Rev 10

5.2.4

Reversing phase

Suppose the current flowed via M21, the load and M12 before reversing phase. Reversing

phase M21 and M12 will be turned off. So now the current will flow through D22, the load and

D11. This leads to a fast current decay.

5.2.5

Chopper control by oscillator

Both chopping circuits work with offset phase. One chopper will switch on the bridge at the

maximum voltage of the oscillator while the other chopper will switch on the bridge at

minimum voltage of the oscillator.

MS1 and MS2 blank switching spikes that could lead to errors of the current control circuit.

Figure 6.

Principal chopper control circuit