Systems and methods for powering driver circuitry

A system for powering driver circuitry for an upper transistor of a half-bridge switching stage, comprising:

• charging control circuitry configured to selectively charge a boot-strap capacitor of the half-bridge switching stage by applying a first voltage source to the boot-strap capacitor when a voltage at the boot-strap capacitor is less than a first threshold, and disconnecting the first voltage source to the boot-strap capacitor when the voltage at the boot-strap capacitor exceeds a second threshold, such that the voltage at the boot-strap capacitor remains within a predetermined voltage range between the first threshold and the second threshold;
• and
• clamping circuitry configured to clamp the voltage at the boot-strap capacitor to prevent the voltage at boot-strap capacitor from exceeding a predetermined maximum value, wherein the clamping circuitry clamps the voltage at the boot-strap capacitor independent of the charging of the charging control circuitry,
• wherein the driver circuitry is powered at least partially via the boot-strap capacitor to drive the upper transistor of the half-bridge switching stage, and
• wherein the system is configured to electrically power the upper transistor of the half-bridge switching stage by applying a second voltage source separate from the first voltage source of the charging control circuitry and the clamping circuitry to the upper transistor of the half-bridge switching stage.

A half-bridge switching stage, comprising:

• an upper field effect transistor (FET) electrically coupled between a first node and a second node;
• a lower field effect transistor electrically coupled between the second node and a third node;
• driver circuitry configured to drive a gate of the upper FET;
• a boot-strap capacitor electrically coupled to the second node and configured to at least partially power the driver circuitry;
• charging control circuitry configured to selectively charge the boot-strap capacitor by applying a first voltage source to the boot-strap capacitor when a voltage at the boot-strap capacitor is less than a first threshold, and disconnecting the first voltage source to the boot-strap capacitor when the voltage at the boot-strap capacitor exceeds a second threshold, such that the voltage at the boot-strap capacitor remains within a predetermined voltage range between the first threshold and the second threshold;
• and
• clamping circuitry configured to clamp the voltage at the boot-strap capacitor to prevent the voltage at the boot-strap capacitor from exceeding a predetermined maximum value, wherein the clamping circuitry clamps the voltage at the boot-strap capacitor independent of the charging of the charging control circuitry,
• wherein the driver circuitry is powered at least partially via the boot-strap capacitor to drive the upper FET of the half-bridge switching stage, and
• wherein the half-bridge switching stage is configured to electrically power the upper FET of the half-bridge switching stage by applying a second voltage source separate from the first voltage source of the charging control circuitry and the clamping circuitry to the upper FET of the half-bridge switching stage.