[sdiy] AS3394E: Practical power supply?

[Tom Bugs]

 From the datasheet:
"The AS3394E was designed to operate from +5V and -6.5V supplies. The 
non-standard negative supply was
necessary not to compromise the VCO frequency resolution, which ranges 
from -4 to +4 volts, in favor of a -5V
supply (this is because there needs to be 4 diode drops for the current 
mirrors).Any one of the readily
available 3-terminal regulators may be used to supply the -6.5V negative 
supply. Since the stability and jitter of
the VCO are directly affected by noise on the positive supply, a supply 
as stable and clean as possible should
be use (not the +5Vdigital supply) Maximum supply allowable across the 
device is 25 volts."

When I've tried CEM & AS chips I've used a 78L05 for the +ve and LM337LZ 
for the -6.5V (only marginally more complicated than a 79L0X type).
But I've still never quite zoned in to suitable ranges & offsets for all 
the control pins so my projects have always remained stuck :(

Tom

On 18/11/2021 15:31, Roman Sowa wrote:
> Why not 7905?
> It's -6.5V maximum, 5V recommended.
>
> Roman
>
> W dniu 2021-11-18 o 15:09, Benjamin Tremblay via Synth-diy pisze:
>> Greetings,
>>
>> I have been intrigued by the CEM3394 for a long time. I realize it’s 
>> the part of the Sequential Six Trak I like; the rest of the Six Trak 
>> leaves a lot to be desired.
>>
>> What is a straightforward way to obtain the -6.5V negative supply? 
>> Use a 9V regulator and drop it with diodes? Use an adjustable 
>> switching supply? Add a feedback loop to a regulator? I’m assuming 
>> even a gaggle of 3394 chips won’t consume much current on the 
>> negative side.
>>
>> I’m lazy (working 2 jobs and taking care of 2 kids and a puppy) and I 
>> won’t get much done unless I can breadboard the chip and try out some 
>> s/h ideas.
>>
>> Thanks,
>> Ben
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