Hi Amps Team,
what is the min required outputresistor to drive a capacitive load of 10nF ?
Ideal would be to calculate the filter based on the signal requirements and ADC and then check if TLV9064 works, but is there a general value for driving outputcapacitance between 1nF and 10nF ?
Many Thanks
Best wishes,
Olrik
Hi Olrik,
It will probably depend on your schematic. Is there anything else going on or is this just a buffer? Is the amp driving a LPF followed by an ADC? In this case, the input capacitance of the ADC may need to be considered.
I ran some basic simulations with a 1nF and 10nF capacitor. You can see the approximate minimum isolation resistor values that you will need here for stability, though you'll probably want a little more phase margin. I've also added the TINA setup I used to the end of this post.
The ADC team also has an excellent resource for picking these values for SAR ADCs. They use a combination of the Analog Engineer's Calculator's ADC SAR Drive calculator and TINA-TI to find the values needed for the LPF. The process is explained in a series of presentations beginning with this one. I recommend going over the slides in PDF format, rather than the videos if you are time constrained.
Regards,
Daniel
