Invention Grant
- Patent Title: MEMS transducer amplifiers
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Application No.: US16549625Application Date: 2019-08-23
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Publication No.: US10582309B2Publication Date: 2020-03-03
- Inventor: Hynek Saman , James Thomas Deas
- Applicant: Cirrus Logic International Semiconductor Ltd.
- Applicant Address: US TX Austin
- Assignee: Cirrus Logic, Inc.
- Current Assignee: Cirrus Logic, Inc.
- Current Assignee Address: US TX Austin
- Agency: Jackson Walker L.L.P.
- Priority: GB1706080.7 20170418
- Main IPC: H04R19/04
- IPC: H04R19/04 ; H04R19/00 ; H03F3/187 ; H03F3/45

Abstract:
This applications relates to methods and apparatus for amplifying signals from capacitive transducers, in particular MEMS transducers such as MEMS capacitive microphones. An amplifier circuit has a signal node for receiving the input signal, a transducer biasing node for outputting a transducer bias voltage for biasing the capacitive transducer, and a voltage buffer configured to generate a buffered bias voltage at a buffer node. An amplifier arrangement is configured to receive the input signal from the signal node and the buffered bias voltage. The amplifier circuit comprises a signal path for supplying the buffered bias voltage to the transducer biasing node via a first capacitance, and the amplifier arrangement comprises a feedback resistor network configured such that: a change in input signal with respect to the buffered bias voltage results in a change in the output signal with respect to the buffered bias voltage with a gain greater than one; and a change in the buffered bias voltage results in a change in the output signal with a gain equal to one.
Public/Granted literature
- US20190379984A1 MEMS TRANSDUCER AMPLIFIERS Public/Granted day:2019-12-12
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