Invention Grant
- Patent Title: Low noise amplifier for MEMS capacitive transducers
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Application No.: US14700666Application Date: 2015-04-30
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Publication No.: US09729114B2Publication Date: 2017-08-08
- Inventor: Santosh Astgimath
- Applicant: Cirrus Logic International Semiconductor Ltd.
- Applicant Address: GB Edinburgh
- Assignee: Cirrus Logic International Semiconductor Ltd.
- Current Assignee: Cirrus Logic International Semiconductor Ltd.
- Current Assignee Address: GB Edinburgh
- Agency: Jackson Walker L.L.P.
- Priority: GB1407790.3 20140502
- Main IPC: H03F99/00
- IPC: H03F99/00 ; H04R3/00 ; H03F3/50 ; H03F1/26 ; H03F3/183 ; H03F3/187 ; H03F1/02 ; H03G1/00 ; H03G3/00

Abstract:
This application relates to amplifier circuitry for amplifying a signal from a MEMS transducer. A super source follower circuit (40) is provided which includes a feedback path from its output node (Nout) to a control bias node (BC) in order to provide a preamplifier signal gain that may be greater than unity. A first transistor (M1) is configured to have its gate node connected to an input node (NIN) for receiving the input signal (VIN) and its drain node connected to an input node (X) of an output stage (A). The source node of the first transistor is connected to the output node (NOUT). A current source (I2) is configured to deliver a current to the drain node of the first transistor (M1), wherein the current source (I2) is controlled by a bias control voltage (VBC) at the bias control node (BC). A feedback impedance network (Z1) comprising a first port connected to the output node (NOUT) and a second port connected to the bias control node (BC) is provided.
Public/Granted literature
- US20150318829A1 LOW NOISE AMPLIFIER FOR MEMS CAPACITIVE TRANSDUCERS Public/Granted day:2015-11-05
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