Hysteretic switching regulator with reduced switching frequency variation
AssigneeBroadcom Corporation
InventorsEric Martin Hayes, Ryan Desrosiers
Life of this patent
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Abstract
Embodiments of a hysteretic switching regulator with reduced switching frequency variation over changes in one or more of input voltage, output voltage, and temperature are provided herein. A frequency adjust controller is specifically used to adjust a parameter of an integrator within the hysteretic switching regulator to compensate for changes in one or more of input voltage, output voltage, and temperature to maintain the switching frequency of the regulator within a narrow frequency range. Limiting the potentially wide switching frequency variation makes filtering of electromagnetic interference (EMI) caused by the switching action of the hysteretic switching regulator more effective and simpler to implement.
Claims21
A hysteretic switching regulator with reduced switching frequency variation, comprising:
- a pre-driver module configured to provide a drive signal based on a comparator signal;
- a power switch module configured to couple and decouple an unregulated input voltage to a first end of an inductor based on the drive signal to provide a regulated output voltage at a second end of the inductor;
- an integrator configured to integrate a voltage across the inductor to provide a ramp signal;
- a hysteretic comparator configured to compare the ramp signal with a reference signal to provide the comparator signal;
- and
- a frequency adjust controller configured to adjust a parameter of the integrator to maintain a frequency at which the power switch module couples and decouples the unregulated input voltage to the first end of the inductor.
A method for operating a hysteretic switching regulator to reduce switching frequency variation, comprising:
- providing a drive signal based on a comparator signal;
- coupling and decoupling an unregulated input voltage to a first end of an inductor based on the drive signal to provide a regulated output voltage at a second end of the inductor;
- integrating a voltage across the inductor, using an integrator, to provide a ramp signal;
- comparing the ramp signal with a reference signal to provide the comparator signal;
- and
- adjusting a parameter of the integrator to maintain a frequency at which the unregulated input voltage is coupled and decoupled to the first end of the inductor.
A hysteretic switching regulator with reduced switching frequency variation, comprising:
- a pre-driver module configured to provide a drive signal based on a comparator signal;
- a power switch module configured to couple and decouple an unregulated input voltage to a first end of an inductor based on the drive signal to provide a regulated output voltage at a second end of the inductor;
- an integrator configured to integrate a voltage across the inductor to provide a ramp signal;
- a hysteretic comparator configured to compare the ramp signal with a reference signal to provide the comparator signal;
- and
- a frequency adjust controller configured to adjust a resistor of the integrator or a capacitor of the integrator to maintain a frequency at which the power switch module couples and decouples the unregulated input voltage to the first end of the inductor within a desired frequency range.
Dependencies are inferred from the claim text.