A low-noise bandgap circuit using pure MOSFETs

Abstract

A low-noise bandgap circuit using pure MOSFETs includes a non-overlapping clock circuit, an output filter circuit, and a bandgap circuit. The non-overlapping clock circuit generates two sets of non-overlapping clock signals to control twelve switching transistors in the bandgap circuit. By modulating the switching transistors, the bandgap current is generated in both the left and right branches within one clock cycle, resulting in a more symmetrical circuit. Simultaneously, power supply noise is shifted to the high-frequency domain and filtered out at the output. This invention modulates noise by adding switches controlled by a non-overlapping clock to the bandgap circuit and controls the bandgap current generation loop through these switches. Replacing traditional PNP transistors with DTMOS transistors significantly reduces output noise while improving the accuracy of the reference current, building upon the advantage of a simpler structure. This allows the circuit to be applied in a wider range of environments.

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