| Author |
Message |
xwcwc1234
Joined: 21 Jul 2001
Posts: 313
Helped: 5
|
 09 Dec 2004 8:34 microphone circuit design |
|
|
|
Hi ,
I need to design a microphone preamp circuit using CMOS technology. Anyone knows what is the detailed spec. for microphone , that means , does the preamp need very low noise or high gain ?
|
|
| Back to top |
|
 |
LCI
Joined: 09 Sep 2004
Posts: 8
|
| 09 Dec 2004 9:36 Re: microphone circuit design |
|
|
|
The noise should depend on the overall SNR (for audio application, usually not very high >85, a-weighted). THD not need high >60dB.
and it may not need high gain but a programable gain (0-30dB)with some anti-alising filter.
other spec such as input swing, input resistance>10kohm, power and area.
addition function is need such as mute and power up/down.
|
|
| Back to top |
|
|
xwcwc1234
Joined: 21 Jul 2001
Posts: 313
Helped: 5
|
| 10 Dec 2004 5:26 Re: microphone circuit design |
|
|
|
To LCI ,
Thank you . Do you have some reference materials on this subject(papers , thesis , or others) ? Can you upload here ?
|
|
| Back to top |
|
|
LCI
Joined: 09 Sep 2004
Posts: 8
|
| 10 Dec 2004 11:15 Re: microphone circuit design |
|
|
|
For spec., u can go to some microelectronic company to download their data sheet,
e.g., http://www.wolfsonmicro.com/products/digital_audio/
Also, when u design the microphone, u should also know the whole ADC channel
and other part which is connect to microphone,
e.g., the ADC is discrete time circuit, u need to know the ADC sampling frequnecy and resolution in order to calulate the settling spec for the microphone.
hope this help.
|
|
| Back to top |
|
|
