[sdiy] RE: Re: [sdiy] Overdriving 4069UB

[Seb Francis]

René Schmitz wrote:

> Hi Bbob,
>
> rdrake wrote:
>
>> René Schmitz has a VCO based on the 4069 
>> (http://www.uni-bonn.de/~uzs159/vco4069.html); he mentions that the 
>> chip runs hot at 15 volts but apparently doesn't burn up.  I've got 2 
>> running at 12 volts and have never noticed any heat issue at all.
>
>
> It gets a little warm, but here only two gates are used in the linear 
> mode.
> But I use 3 gates with my threephase LFO also @15V, and this seems to 
> work fine also.
>
For this at least the datasheet gives a useful spec.  The absolute max 
power dissipation for a DIP package is 700mW.  So measure the VDD 
current drawn (with no signal - worst case for linear mode use), and 
mutiple by VDD.  In my case, using 3 gates in linear mode drew 28mA at 
15V (=420mW) and ran warm to touch (but not painful!)

Seb