Switching drivers with voltage monitoring

Abstract

A switching driver 200 has first and second switches 103-1, 103-2 for selectively connecting output node 104 to first and second switching voltages VP, VN respectively to generate an output voltage Sout. A compensator (Fig.4) receives a first monitor signal VCM indicative of a sum of the first and second switching voltages and a second monitor signal VDIFF indicative of a difference between the first and second switching voltages. The compensator applies compensation to the input signal based on the first and second monitor signals to compensate for variations in the switching voltages from their defined nominal values. A modulator 205 controls a duty cycle of the first and second switches based on the input signal after the compensation has been applied. In one arrangement, the modulator includes the compensator (Fig.3, 301). In another arrangement, a first analog-to-digital converter (ADC) 201 receives the sum of the switching voltages and outputs the first monitor signal, and a second ADC 202 receives the difference of the switching voltages and outputs the second monitor signal. The switching driver may drive a load 101, such as an audio transducer, in a single-ended or bridge-tied load (BTL) configuration.

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