Re: GAL running hot

From: silverdr_at_wfmh.org.pl
Date: Thu, 7 Jun 2018 12:44:17 +0200
Message-Id: <A4FF6364-9080-495D-B0FE-67020D503F77@wfmh.org.pl>
> On 2018-04-20, at 19:00, silverdr@wfmh.org.pl wrote:
> 
>>>>> Unfortunately not /that/ GAL.. anyway - I made a small circuit (the first successful one in KiCAD I wrote about not long ago) for the 64 that employs the small 16V8 GAL chip. All works fine but the (Lattice) chip runs surprisingly hot. Does anyone have any experience with GALs and with what can affect their power consumption?
>>>> 
>>>> In my experience, old PALs and GALs run hot,
>>> The datasheet says it should take in the range of 70mA, which makes it less than half W. Yeah, much more than an LS chip but OTOH not /that/ much..
>> 
>> Yes, but half a watt in such a small case gets quite hot. A 6569 VIC in a C64 uses about 1.5W (200mA/5V and about 40mA/12V) and gets pretty hot (above 60C on the surface without heatsink).
> 
> True, and the case is small - especially that it's a PLCC - so it might actually be something to learn to live with. I am still wondering if the power usage could be noticeably depending on the way it is programmed, which pins are used, etc. I'll check the Atmel once I get a programmer that can handle them. I needed to use Lattice as it was the only type my programmer could work reliably with but Atmel advertises lower currents in their datasheet.

Eventually managed to program Atmel chip and the result is very satisfying. It runs at noticeably lower temp than the Lattice did, well in the acceptable range of highly scientific, worl-wide recongnised "doesn't burn your fingers" ISO/IEEE norm ;-)

-- 
SD! - http://e4aws.silverdr.com/
Received on 2018-06-07 13:01:53

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