Boost regulator with pulse frequency mode of operation having substantially constant percentage output ripple and frequency

A voltage regulator comprising:

• first circuitry configured to receive an input voltage and generate an output voltage, the first circuitry comprising an inductor;
• and
• second circuitry configured to control a current through the inductor using a current limit reference, the second circuitry comprising circuitry configured to modulate the current limit reference based on the input voltage and the output voltage,
• wherein the circuitry configured to modulate the current limit reference comprises:
• a current source configured to generate a reference current, the current limit reference based on the reference current;
• and
• a modulator configured to modulate the reference current based on the input and output voltages,
• wherein the current source is configured to generate the reference current such that the reference current is based on a product of a square root of a first input current and a second input current, the first input current based on the output voltage, the second input current based on the input and output voltages.

A system comprising:

• an input voltage source configured to provide an input voltage;
• and
• a voltage regulator comprising:
• first circuitry configured to receive an input voltage and generate an output voltage, the first circuitry comprising an inductor;
• second circuitry configured to control a current through the inductor using a current limit reference, the second circuitry comprising circuitry configured to modulate the current limit reference based on the input voltage and the output voltage,
• the second circuitry further comprises a comparator configured to compare a sense signal associated with the current through the inductor to the current limit reference;
• and
• the circuitry configured to modulate the current limit reference comprises:
• a current source configured to generate a reference current, the current limit reference based on the reference current;
• a modulator configured to modulate the reference current based on the input and output voltages
• a voltage-to-current converter configured to generate first and second input currents, the modulator configured to modulate the reference current based on the first and second input currents;
• wherein the first input current is based on the output voltage;
• wherein the second input current is based on a difference between the output voltage and the input voltage;
• and
• wherein the reference current is based on a square root of a product of (i) the output voltage and (ii) the difference between the output voltage and the input voltage.