[sdiy] 2164 overvoltage condition?

[Sean Ellis]

Ha a damaged IC wont put me off! I always use the breadboard before ordering a pcb or putting together something on veroboard, spice doesn't seem to be very helpful when using logic in analog circuits. In this case it's an expensive lesson to pay more attention...


In case anyone is wondering I've been trying to get the Bi-N-Tic switched capacitor filter to work with a 2164 core. So far the result has been pretty bad

with such small integrator caps. I tried changing cutoff ranges and using high quality switching IC's, lots of things actually, but so far haven't got the same comb filter ringing as the original 47n value.  If anyone has a suggestion as to how to increase the integrator values to be so large using a 2164 or OTA I could use the help :)


________________________________
From: Tom Wiltshire <tom at electricdruid.net>
Sent: Wednesday, 28 June 2017 7:54 AM
To: Sean Ellis
Cc: synth-diy at synth-diy.org
Subject: Re: [sdiy] 2164 overvoltage condition?

Don't let them put you off, Sean!

I've breadboarded a lot of circuits with the 2164. It *is* a chip you have to be careful with, but I've only fried a couple in nearly ten years. That's not so bad! I've fried more PICs than that, but I probably wasn't so careful with them (cheaper =  more abuse!).

I've got V2164s in the shop, and we post to Australia (from Portugal), but something more local ought to arrive quicker.

http://electricdruid.net/product/v2164-quad-vca/
V2164 Quad VCA | Electric Druid<http://electricdruid.net/product/v2164-quad-vca/>
electricdruid.net
Description. The CoolAudio V2164 quad vca chip is a great chip for making VCFs or VCAs. Download V2164 datasheet



HTH,
Tom

==================
       Electric Druid
Synth & Stompbox DIY
==================



On 27 Jun 2017, at 05:53, rsdio at audiobanshee.com wrote:

> With breadboards, there is also the potential for ESD since you're handling wires directly. The human body can generate tens of thousands of Volts and easily fry a chip that's not protected by soldered-in circuit connections.
>
> David's last email is probably describing exactly what happened: (nearly) infinite current input due to lack of a current-limiting resistor in series with the input.
>
> Brian
>
>
> On Jun 26, 2017, at 9:27 PM, David G Dixon <dixon at mail.ubc.ca> wrote:
>> The 2164 is very fussy about power connections.  If you only connect one rail, it dies.  If you fail to connect the ground, it dies.  And it dies permanently.
>>
>> This is probably why I almost never breadboard.  Once I figure I've got the circuit right, I just make a PCB.  I prefer the security of soldered connections, and it's no harder to lay out a PCB than to plan out a breadboard.  Also, since I typically don't make any layout mistakes, I usually end up with a usable board straightaway, without all that pesky breadboarding nonsense.
>>
>> From: Sean Ellis
>>> I've been breadboarding a filter and oscillator using a single 2164 and I think I just fried my only 2164 on hand. I have the power supply protected but accidentally put -12 straight into the input of one amp (the control pin was at about 2.5V) and suddenly it died. The datasheet specifies the max ratings to the supply rails so I don't get why it could have (seemingly) destroyed the chip. Could it maybe have caused excessive heat?
>>
>
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