CGS48 staircase generator question
2013-06-26 by synchroton
Hi, I was playing around with the staircase generator and had a few questions -
When it comes to tuning the circuit, the page just says to tweak the trimmer until you get the best tracking range...
I'm interested in using it as a suboscillator as well as a pulse divider (so, using it at very low frequencies with a clock input) and obviously for this to work the circuit has to properly 'integrate' - that is, hold the voltage and not drop or rise. The range of adjustment on the trimmer is very wide when trying to accomplish this, there's a very small 'sweet spot' where this works. I'm wondering if it would help to add a more precise trimmer here. But is this all in vain - is there a temperature dependence for the circuit that means I'll never really be able to 'null' it?
Also, I'm wondering if making this adjustment by watching the staircase output voltage is going to also make it track the best and is a simpler method of establishing the optimum setpoint. Intuitively, I'd expect that if it's gaining or losing voltage over time that it's going to respond more poorly at low frequencies... Just wondering if anyone's played around with this a bit more.
Also is there a capacitor type substitution that would increase its low frequency performance? I've got a polyester in there currently.
When it comes to tuning the circuit, the page just says to tweak the trimmer until you get the best tracking range...
I'm interested in using it as a suboscillator as well as a pulse divider (so, using it at very low frequencies with a clock input) and obviously for this to work the circuit has to properly 'integrate' - that is, hold the voltage and not drop or rise. The range of adjustment on the trimmer is very wide when trying to accomplish this, there's a very small 'sweet spot' where this works. I'm wondering if it would help to add a more precise trimmer here. But is this all in vain - is there a temperature dependence for the circuit that means I'll never really be able to 'null' it?
Also, I'm wondering if making this adjustment by watching the staircase output voltage is going to also make it track the best and is a simpler method of establishing the optimum setpoint. Intuitively, I'd expect that if it's gaining or losing voltage over time that it's going to respond more poorly at low frequencies... Just wondering if anyone's played around with this a bit more.
Also is there a capacitor type substitution that would increase its low frequency performance? I've got a polyester in there currently.