[sdiy] ripple counters

[harry bissell]

On Tuesday 20 June 2006 03:49 pm, mark verbos wrote:
>> Hi everybody,
>>
>> I'm planning to build a voltage controlled delay using the Sigma Delta
>> technique, with 4164 RAMs similar to the one on Batz's page or the Delta
>> Labs stuff. I'm putting together the clocking section and I was planning
>> to use a 4040 or a pair of 4024s to count the RAMs, but I'm wondering if
>> the fact that they're ripple counters will screw the circuit up. So my
>> question is.... How long do they actually have chaos between steps and
>> is it enough to confuse the RAM in something like this? Obviously it
>> will depend on how fast the circuit is clocked, but what is the breaking
>> point? The data sheet claims that the 4040 can go up to 6MHz. Should I
>> just use 40193s to be safe? They only claim to go up to 8 MHz. Plus,
>> they only have 4 outs each, so it will take more chips. Anyone have
>> experience with this?
>>     
I'd go with synchronous counters for sure. I tried a ripple counter 
driving a DAC at  low audio
rates and had a LOT of glitches.  Synchronous counters fixed it. If it 
does that at low frequencies
picture YOUR application  At five volt logic I'd look at the 74HC series 
cmos

H^) harry