Adjustable biasing circuits for MEMS capacitive microphones

摘要

An adjustable charge pump system. The system includes a voltage regulator, a clock circuit, a voltage adjustment circuit, and a charge pump. The voltage regulator is configured to receive an input voltage and output a regulated voltage. The clock circuit is coupled to the voltage regulator and receives the regulated voltage. The voltage adjustment circuit is coupled to the voltage regulator and is configured to receive the regulated voltage and to output a driver voltage. The charge pump includes a plurality of stages. The output of the adjustable charge pump system is adjusted by disabling one or more stages of the first stage and the plurality of subsequent stages.

主权项

1. An adjustable charge pump system, comprising:
a voltage regulator configured to receive an input voltage and output a regulated voltage; a clock circuit coupled to the voltage regulator and receiving the regulated voltage; a voltage adjustment circuit coupled to the voltage regulator and configured to receive the regulated voltage and to output a driver voltage; and a charge pump, including
a first stage coupled to the voltage adjustment circuit and the clock circuit and comprising a plurality of switched latches, the first stage receiving the driver voltage and the regulated voltage and outputting a first stage output voltage approximately equal to the sum of the driver voltage and the regulated voltage, anda plurality of subsequent stages coupled to a stage just prior and the clock circuit and comprising a plurality of switched latches, each of the plurality of subsequent stages receiving a stage input voltage and the regulated voltage and outputting a stage output voltage approximately equal to the sum of the stage input voltage and the regulated voltage;wherein an output of the adjustable charge pump system is adjusted by disabling one or more stages of the first stage and the plurality of subsequent stages.