Low dropout regulator with less quiescent current in dropout region
AssigneeDialog Semiconductor (UK) Limited
InventorsSusumu Tanimoto, Hiroki Asano
Life of this patent
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Abstract
A Low Dropout Regulator (LDO) with Less Quiescent Current in the Dropout Region is described, including an error amplifier configured to compare a reference voltage to an LDO output voltage across a resistive divider, a current mirror configured to mirror a first output of the error amplifier to a first and second output of the current mirror, and a comparator configured to compare the LDO output voltage to a second output of the error amplifier, which has been compared to the second output of the current mirror, and configured to output a control voltage to the error amplifier, where a low quiescent current is maintained when an LDO input voltage is near or less than the LDO output voltage.
Claims20
A Low Dropout Regulator (LDO) with Less Quiescent Current in the Dropout Region, comprising:
- an error amplifier, configured to compare a reference voltage to an LDO output voltage across a resistive divider;
- a current mirror, configured to mirror a first output of the error amplifier to a first and second output of the current mirror;
- and
- a comparator, configured to compare the LDO output voltage to a second output of the error amplifier, which has been combined with the second output of the current mirror, and configured to output a control voltage to the error amplifier,
- wherein a low quiescent current is maintained when an LDO input voltage is almost equal to or less than the LDO output voltage.
A method for operating a Low Dropout Regulator (LDO) with Less Quiescent Current in the Dropout Region, comprising:
- comparing a reference voltage to an LDO output voltage across a resistive divider, using an error amplifier;
- mirroring a first output of the error amplifier to a first and a second output of a current mirror;
- and
- comparing the LDO output voltage to a second output of the error amplifier, which has been combined with the second output of the current mirror, and outputting a control voltage to the error amplifier.
Dependencies are inferred from the claim text.