Current pulse count control in a voltage regulator

An integrated circuit chip for providing a regulated voltage at an output by charging and discharging an inductor, the integrated circuit chip comprising:

• a first comparator configured to:
• indicate if the voltage at the output is above a high voltage threshold;
• and
• indicate if the voltage at the output is below a low voltage threshold;
• a current sensor configured to sense a current propagating through the inductor;
• a second comparator configured to indicate based on a signal from the current sensor, if the current propagating through the inductor is above an upper current threshold;
• a digital circuit configured to:
• determine based on an output from the first comparator, if the output voltage drops below a low voltage threshold;
• if the output voltage drops below the low voltage threshold, provide a burst of current pulses to raise the output voltage;
• provide to the second comparator, a digital value corresponding to the upper current threshold;
• during the burst of current pulses, determine based on an output from the second comparator, if the current through the inductor raises above the upper current threshold;
• provide each current pulse in the burst by:
• setting the regulator to a charge state;
• if the current through the inductor raises above the upper current threshold during the charge state, setting the regulator to a discharge state;
• during the burst of current pulses, determine based on an output from the first comparator, if the output voltage raises above a high voltage threshold;
• if the output voltage raises above the high voltage threshold, discontinue the burst;
• count a number of current pulses in the burst;
• compare the number of current pulses to at least one pulse count threshold;
• and
• adjust the upper current threshold based on the number of current pulses.

A method of regulating voltage with a switching regulator, the method comprising:

• sensing an output voltage provided by the switching regulator;
• each time the output voltage drops below a low voltage threshold, providing a burst of one or more current pulses to raise the output voltage until the output voltage reaches a high voltage threshold, then discontinuing the burst of current pulses, wherein providing each current pulse in the burst includes setting the voltage regulator to a charge state until a current through an inductor reaches an upper current threshold, then setting the voltage regulator to a discharge state;
• and
• for each burst:
• counting a number of the one or more current pulses used to raise the output voltage from the low voltage threshold to the high voltage threshold;
• if the number of the one or more current pulses is less than a low pulse threshold and the upper current threshold is above a lower limit, reducing the upper current threshold;
• if the number of the one or more current pulses is less than the low pulse threshold and the upper current threshold is at the lower limit, maintaining the upper current threshold at the lower limit;
• if the number of the one or more current pulses is greater than a high pulse threshold and the upper current threshold is below the upper limit, increasing the upper current threshold;
• if the number of the one or more current pulses is greater than a high pulse threshold and the upper current threshold is at the upper limit, maintaining the upper current threshold at the upper limit;
• and
• if the number of the one or more current pulses is equal to or between the low pulse threshold and the high pulse threshold, maintaining the upper current threshold.

A switching voltage regulator comprising:

• an inductor coupled in series between an input of the regulator and an output of the regulator;
• a first comparator configured to:
• indicate if the voltage at the output is above a high voltage threshold;
• and
• indicate if the voltage at the output is below a low voltage threshold;
• a current sensor configured to sense a current propagating through the inductor;
• a second comparator configured to indicate based on a signal from the current sensor, if the current propagating through the inductor is above an upper current threshold;
• a digital circuit configured to:
• determine based on an output from the first comparator, if the output voltage drops below a low voltage threshold;
• if the output voltage drops below the low voltage threshold, provide a burst of current pulses to raise the output voltage;
• provide to the second comparator, a digital value corresponding to the upper current threshold;
• during the burst of current pulses, determine based on an output from the second comparator, if the current through the inductor raises above the upper current threshold;
• provide each current pulse in the burst by:
• setting the regulator to a charge state;
• if the current through the inductor raises above the upper current threshold during the charge state, setting the regulator to a discharge state;
• during the burst of current pulses, determine based on an output from the first comparator, if the output voltage raises above a high voltage threshold;
• if the output voltage raises above the high voltage threshold, discontinue the burst;
• count a number of current pulses in the burst;
• compare the number of current pulses to at least one pulse count threshold;
• and
• adjust the upper current threshold based on the number of current pulses.

A system comprising:

• a power source;
• an electronic circuit;
• and
• a switching voltage regulator coupled between the power source and the electronic circuit, the switching voltage regulator configured to draw power from the power source and provide regulator power to the electronic circuit, the switching voltage regulator including:
• an inductor coupled in series between an input of the regulator and an output of the regulator;
• a first comparator configured to:
• indicate if the voltage at the output is above a high voltage threshold;
• and
• indicate if the voltage at the output is below a low voltage threshold;
• a current sensor configured to sense a current propagating through the inductor;
• a second comparator configured to indicate based on a signal from the current sensor, if the current propagating through the inductor is above an upper current threshold;
• a digital circuit configured to:
• each time the output voltage drops below a low voltage threshold, provide a burst of one or more current pulses to raise the output voltage until the output voltage reaches a high voltage threshold, then discontinue the burst of current pulses, wherein provide each current pulse in the burst includes set the voltage regulator to a charge state until a current through an inductor reaches an upper current threshold, then set the voltage regulator to a discharge state;
• and
• for each burst:
• count a number of the one or more current pulses used to raise the output voltage from the low voltage threshold to the high voltage threshold;
• if the number of the one or more current pulses is less than a low pulse threshold and the upper current threshold is above a lower limit, reduce the upper current threshold;
• if the number of the one or more current pulses is less than the low pulse threshold and the upper current threshold is at the lower limit, maintain the upper current threshold at the lower limit;
• if the number of the one or more current pulses is greater than a high pulse threshold and the upper current threshold is below the upper limit, increase the upper current threshold;
• if the number of the one or more current pulses is greater than a high pulse threshold and the upper current threshold is at the upper limit, maintain the upper current threshold at the upper limit;
• and
• if the number of the one or more current pulses is equal to or between the low pulse threshold and the high pulse threshold, maintain the upper current threshold.