Guys...
Hopefully someone has some experience with the Holtek HT9032D CID decoder chip. I purchase 5 pieces off of eBay and threw together a quicky test jig. See image. Using a DDS set to 1200 Hz (or 2200 Hz, the CID FSK tones), I get no activity at the DOUT pin. I've tried several of the 4 ICs and no luck. This shouldn't be any easier. The input circuit is biased a 2.5V although I am seeing about 100 mV DC differential between the TIP/RING inputs. This seems high considering the datasheet details a sensitivity of something like -39 dBm. I've also swung the input FSK test signal +/- some 100 Hz or so. Nothing. All I was wanting to do is to manually swing the FSK tones back and forth to see if the decoder would work.
Anyone have any first hand experience with this part?
Thanks
Jim
Largo, Florida