Architecture for piezoresistive pressure sensor drivers and power management

A MEMS pressure sensor circuit, comprising:

• a multiplexer configured to pass either a first voltage or a second voltage at its output;
• an analog front end (AFE) configured to condition the output of the multiplexer to produce an ADC input;
• an analog-to-digital converter (ADC) configured to digitize the ADC input to produce an ADC output;
• a first Wheatstone bridge sensitive to pressure and configured to sense pressure applied thereto and generate the first voltage based upon the sensed pressure;
• a second Wheatstone bridge sensitive to temperature and configured to sense temperature applied thereto and generate the second voltage based upon the sensed temperature;
• a voltage regulator arrangement comprising:
• switch circuitry;
• and
• an amplifier having a first input coupled to receive a reference voltage and a second input selectively couplable by the switch circuitry to a top of the first Wheatstone bridge so that a first feedback resistive divider is formed by a series combination of a first trimmable resistor and the first Wheatstone bridge during a pressure sensing period or to a top of the second Wheatstone bridge so that a second feedback resistive divider is formed by a series combination of a second trimmable resistor and the second Wheatstone bridge during a temperature sensing period, wherein a regulated voltage is generated at an output of the amplifier;
• and
• control circuitry configured to control the switch circuitry to cause the voltage regulator arrangement to use the first Wheatstone bridge in the first feedback resistive divider to generate the regulated voltage during the pressure sensing period, and to cause the voltage regulator arrangement to use the second Wheatstone bridge in the second feedback resistive divider to generate the regulated voltage during the temperature sensing period;
• wherein the AFE and ADC are powered by the regulated voltage, and wherein the AFE and ADC use a feedback voltage generated by the first feedback resistive divider as a reference voltage during the pressure sensing period and use a feedback voltage generated by the second feedback resistive divider as a reference voltage during the pressure sensing period.