[sdiy] Further thoughts on sample and (infinite) hold

[RMC]

hello All

I was thinking about the problem of droop and cap soak etc. and thought of 
this item:

Manufacturer: ISD; device = ISD1416P
. High quality, natural voice record/playback
. 16s minimum duration
. 8kHz Sampling rate
. Zero power message storage
. Fully addressable to handle multiple messages
. Single +5V power supply

This single CMOS record/playback IC uses a patented multi-level storage 
system that allows voice and audio signals to be stored in non-volatile 
memory in their natural form. Direct analogue storage provides a very true, 
natural sounding reproduction of voice, music, tones and sound effects that 
is not normally available with most solid-state digital devices. The 
non-volatile memory provides zero power message storage - a message can be 
retained for up to 100 years without power. Re-record is typically over 
100,000 times.
The device includes an on-chip oscillator, microphone pre-amplifier, 
automatic gain control, antialiasing filter, smoothing filter and speaker 
amplifier. The device requires minimum external components. Supplied in a 
28-pin PDIP

It's available in the UK from Maplin electronics and from Digikey in USA.
http://www.chipdocs.com/datasheets/datasheet-pdf/Information-Storage-Devices/ISD1416.html
http://www.alldatasheet.com/datasheet-pdf/pdf/ETC/ISD1416.html
http://www.datasheetarchive.com/download.php?pi=242315

It looks to me as though you could s&h into the device with some address 
encoding and decoding, use it as an analogue shift register for CVs (within 
the range of the device - might need some gain and padding to suit), and 
most relevantly of all, use it as a very long timeconstant sample and hold 
unit with lots of storage cells.

You might be able to read/wire using the device directly, or use a more 
conventional s&h to generate the plateau to be sampled by the ISD device.  A 
sort of analogue ADC/DAC.


Cheers

RMC, England