In an example, a circuit includes a first comparator, a second comparator, a pulse counter, a processor, a first ADC, and a second ADC. The first comparator has a first input coupled to a first node, a second input, and an output. The second comparator has a first input coupled to a second node, a second input, and an output. A first DAC is coupled to the second input of the first comparator. A second DAC is coupled to the second input of the second comparator. The pulse counter has a first input coupled to the output of the first comparator and a second input coupled to the output of the second comparator. The first ADC has an input coupled to the first node and an output coupled to the processor. The second ADC has an input coupled to the second node and an output coupled to the processor.