Compact voltage regulator with high supply noise rejection

A circuit comprising:

• a reference circuit to provide an input reference voltage;
• an operational amplifier (opamp) having a first opamp input coupled to the reference circuit, a second opamp input, and an opamp output to provide a conditioned reference voltage based on said input reference voltage;
• a differential metal oxide semiconductor (MOS) amplifier having a first input coupled to the opamp output and an output coupled to the second opamp input, the input reference voltage to be conditioned in accordance with the size of transistors in the differential amplifier;
• a second opamp configured as a unity gain amplifier to buffer the conditioned reference voltage;
• and
• a second differential amplifier configured as a load to the second opamp with a path to a power supply node.

A voltage regulator comprising:

• a reference circuit to provide an input reference voltage;
• a first operational amplifier (opamp) having a first opamp input coupled to the reference circuit, a second opamp input, and an opamp output to provide a conditioned reference voltage based on said input reference voltage;
• and
• a differential MOS amplifier having a first input coupled to the opamp output and an output coupled to the second opamp input, the input reference voltage to be subjected to a reduction or gain substantially determined by the relative dimensions of a pair of transistors in the differential amplifier.