Hello team,
Could you please help us to address some customer questions?
1. Is it OK to use PCM3008 with VCC=3.3V? If so, how the PCM3008 input voltage range should be scaled? Will acceptable VIN be 3.3 * 0.6 = 1.98V? I found somebody uses PCM3008 with 3.3V here but I want to make sure.
2. How can I select the PDDA, PDAD resistor and capacitor values? How can I estimate the rise and fall characteristic?
Regards,
Itoh
Hello,
1.) Yes, the specified operating range is from +2.1V to +3.6V.
2.) For a system without a separate control for the PDDA/PDAD you will size the R/C based on the desired time you believe it will take the supply to become stable. The goal will be for the VCC supply to reach a stable value above +2.1V, before the PDAD signal reaches the ~0.7*VCC transition level which will cause the device to exit power-down mode. An example simulation is attached with a supply that ramps from 0 to +3.3V in 10us and a 22k/10nF RC combination that slows the ramp of the PDAD signal. The delay can be less than what is shown here as an example and can be tuned based on how fast the customer desires the system to power-on.
The ramp-down (fall) characteristic will track the VCC supply ramp-down behavior since the PDAD signal will discharge through the D1 diode.
/cfs-file/__key/communityserver-discussions-components-files/6/PD_5F00_Circuits.TSC
