Winbond ISD1700 series

[sghioto]

Trying to find out the frequency response or -3db roll off frequency using the Winbond ISD1760 chip with a 12khz sampling rate. Nothing is mentioned in the data sheets about this. Presently using the ISD2560 chip which has a 8khz sampling rate. Spec sheet for this chip says the -3db roll off is 3.4 khz. which is about half the sampling rate. So could one expect maybe a 5khz roll off using the ISD1760? I need a digital recorder chip that will record to 5khz is why I'm asking. Any suggestions?

Thanks,
Steve Ghioto

[Bigglez]

Greetings Steve,

Trying to find out the frequency response or -3db roll off frequency using the Winbond ISD1760 chip with a 12khz sampling rate.

As there isn't any spec in the data sheet you have two choices,
either ask the manufacturer or test the part yourself.

Generally an anti-alias filter is placed in front of a sampling
circuit to limit the bandwidth to one half the sampling
frequency (Nyquist criterior). This implies that at 12 K
samples per second you can get 6kHz bandwidth,
which may be the case for this chip.

Comments Welcome!

[sghioto]

Peter,

Thanks for the reply. Did some futher research on the A/D conversion and agree with your analysis using the Nyquist criterior.
Ordered a couple of chips and will verify myself.

Steve Ghioto