Microphone bias current measurement circuit
AssigneeTexas Instruments Incorporated
InventorsJohn M. Muza, Roberto Sadkowski, Martin Sallenhag, Heino Wendelrup
Life of this patent
Estimating the term…
Abstract
A microphone bias current detection circuit includes: a microphone circuit 18; an amplifier 10 having a first output and a second output, the first output is coupled to the microphone circuit 18 for providing a bias current to the microphone circuit 18, the second output provides a sampled current Is proportional to the bias current; a first switch 30 having a first end coupled to the second output of the amplifier 10; a resistor 38 having a first end coupled to a second end of the first switch 30; and a second switch 32 coupled between the first end of the resistor 38 and a reference current source.
Claims4
A microphone bias current measurement circuit comprising:
- a microphone circuit;
- an amplifier having a first output and a second output, the first output is coupled to the microphone circuit for providing a bias current to the microphone circuit, the second output provides a sampled current proportional to the bias current;
- a first switch having a first end coupled to the second output of the amplifier;
- a resistor having a first end coupled to a second end of the first switch;
- and
- a second switch coupled between the first end of the resistor and a reference current source.
Dependencies are inferred from the claim text.