Broadcom Corporation

Jasmine Cheng

Jungwoo Song

Derek Tam

Takayuki Hayashi

A circuit with dielectric thicknesses is presented that includes a low-pass filter including one or more semiconductor devices having a thick gate oxide layer, while further semiconductor devices of the circuit have thin gate oxide layers. The low-pass filter semiconductor device includes an N-type substrate, a P-type region formed on the N-type substrate, a thick gate oxide layer formed over the P-type region, a Pgate electrode formed over the thick gate oxide layer and coupled to a first voltage supply line, and Ppick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line. The low-pass filter semiconductor device acts as a capacitor, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the circuit.

Thick oxide P-gate NMOS capacitor for use in a low-pass filter of a circuit and method of making same

In a low-pass filter for a phase locked loop (PLL) circuit, a capacitor formed by an N-type substrate, a P-type region formed on the N-type substrate, a thick oxide formed over the P-type region, a P gate electrode formed over the thick oxide and coupled to a first voltage supply line, and P pick-up terminals formed in the P-type region adjacent the gate electrode and coupled to a second voltage supply line, whereby a gate-to-substrate voltage is maintained at less than zero volts to maintain a stable control voltage for the PLL.

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Irvine, CA, United States of America

Jasmine Cheng