Hi Russ,
Here is the info you asked for;
APC Register: Not sure if this can be done without spi mode. So its a No
Freq: Running at 8KHz going to up it to 12K when I get the right value resistor.
LM386 Application diagram: Here is the link www.quasarelectronics.com/ds/isd-ab6a.pdf
I used this when using the 1200 series chips, so tried it on the 1700 series, connecting it to the spk outputs. Have changed the circuit to the minimum parts diagram with a gain of 20 from the LM386 data sheet, and connected this to the AUD/AUX output.
Mic input: I tried it using the anain (with FT low) as per example #2 then I tried decoupling the Mic- to earth using a 0.1uf cap and a decoupling cap on the Mic+ to the source with a 1k resistor on the isd side between Mic+ and Mic-.
Did some more searching on the net and found the ISD-COB17xxx demo board user manual, this includes a circuit diagram and pcb layout. I am in the process of drawing a PCB board using this as a guide on a single sided PCB. If it would help I could try and up load the layout for you to look at. I would buy one as a trial but there not for sale in UK and postage is a bit steep from USA.
I hope I have provided all the info you asked for..
What sort of quality have you managed to get from these chips? Is the LM386 the right choice of amp for the ISD 1700?
Kind regards Nick
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