• TI Thinks Resolved

TS5A23159 Ringing?


     Looking forward to your help in sorting out this issue. 

The objective is to switch between an analog voltage and ground at high switching speeds with reasonable current drive capability (about 20-30mA). 

The signal sequence is as follows: a microcontroller generates the analog voltage (needs to be software configurable and hence the uC). The uC output is connected to one input of a TS5A23159 analog SPDT, the other input being shorted to ground. The output of the switch is connected to a high speed opamp OP4830 configured in unity gain mode. 

The problem is as follows: The output rings as the switch transistions from ground to analog voltage. Following is the oscilloscope screenshot

The output has to transition from 0 to ~3.5V when this happens. Further, the ringing does not end in the output settling to 3.5V there is some sort of capacitor charging behavior following up.

Following is the screenshot (zoomed out and a larger time frame)


The above measurements are with no-load at the output of the opamp. 

Please advise on the following:

1) How to reduce the ringing

2) The output has to rise from 0 to 1V in less than 200ns (the switching speeds of the chain components add up to this number). 

What could be the reason for such a response?

Thank you for your time in looking into my case,