Stable digital integrator circuit for boost converter

A boost converter circuit, comprising:

• a control circuit with an inner loop and an outer loop, wherein the outer loop comprises:
• a digital integrator circuit having:
• a first comparator with input nodes and an output node;
• a second comparator with two input nodes and an output node;
• a counter with a first input node coupled to the output node of the first comparator and with a second input node coupled to the output node of the second comparator;
• and
• a digital-to-analog converter (DAC) coupled to an output node of the counter, wherein an output of the DAC is a feedback adjustment signal used by the control circuit to determine an on-time for the power switch;
• wherein the output node of the first comparator provides a first control signal to the counter based on a comparison of a first input signal and a second input signal, wherein the first input signal combines a reference voltage with a hysteresis voltage, and wherein the second input signal is a feedback voltage proportional to an output voltage of the boost converter circuit.

A method, comprising:

• receiving a target reference for an output voltage;
• providing a feedback adjustment signal for an inner loop of a boost converter based on a digital counter with a count up function, a count down function, and a pause function;
• and
• regulating the output voltage of the boost converter based on the reference target and the feedback adjustment signal;
• wherein providing the feedback adjustment signal comprises:
• providing a first comparator output based on a comparison of a first input signal and a second input signal, wherein the first input signal combines a reference voltage with a hysteresis voltage, and wherein the second input signal is a feedback voltage proportional with an output voltage of the boost converter;
• providing a second comparator output based on a comparison of the second input signal and a third input signal, wherein the third input signal is the reference voltage;
• providing the first and second output comparator outputs to the digital counter to direct the digital counter to perform one of the count up function, the count down function, and the pause function.