Frequency control circuit and method for a non-constant frequency voltage regulator
AssigneeRichtek Technology Corporation
InventorsChien-Fu Tang, Isaac Y Chen
Life of this patent
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Abstract
A non-constant frequency voltage regulator includes a constant-time trigger to trigger a constant on-time or a constant off-time for a pulse width modulation signal, a current generator to provide a first current to determine the constant on-time or the constant off-time, a power output stage operated by the pulse width modulation signal to produce a load current, and a frequency control circuit for loading feed forward by a second current added to the first current to adjust the constant on-time or the constant off-time for frequency compensation to the pulse width modulation signal.
Claims10
A frequency control circuit for a non-constant frequency voltage regulator including a constant-time trigger to trigger a constant on-time or a constant off-time for a pulse width modulation signal, a current generator to provide a first current for the constant-time trigger to determining a width of the constant on-time or the constant off-time, and a power output stage operated by the pulse width modulation signal to generate a load current, the frequency control circuit comprising:
- a current detector connected to the power output stage, for feeding back a second current representative of a magnitude of a DC component of the load current;
- and
- an adder connected to the current generator, the current detector and the constant-time trigger, for adding the second current to the first current to adjust the width of the constant on-time or the constant off-time for frequency compensation to the pulse width modulation signal.
A frequency control method for a non-constant frequency voltage regulator including a constant-time trigger to trigger a constant on-time or a constant off-time for a pulse width modulation signal, a current generator to provide a first current for the constant-time trigger to determining a width of the constant on-time or the constant off-time, and a power output stage operated by the pulse width modulation signal to generate a load current, the frequency control method comprising the steps of:
- (A) from the power output stage, feeding back a second current representative of a magnitude of a DC component of the load current;
- and
- (B) adding the second current to the first current to adjust the width of the constant on-time or the constant off-time for frequency compensation to the pulse width modulation signal.
Dependencies are inferred from the claim text.