Dear Support ,
We are observing very high negative (till 7V) glitch of 100ns width while using ADG1419, with supply +/-15V. Input signal was reduced to just 1V. Even then during switching we are observing this huge negative glitch. Mostly its around 3V to 5V negative and sometimes its going to -7V.
Any usage of body snatching MOSFET is causing this effect ?
Please let us know what might have caused this issue.
A Overview of Our Application:
We have a signal of +/-1V peak to peak with 200u seconds period & 50% duty cycle. We try to turn on the switch during positive phase and measure one sample and then we turn off the switch after at least 20us. The switch is again turned ON during negative phase and one sample is taken before turning OFF after 20us. While performing this operation, we are seeing this glitch. We kept EN signal high & toggled just IN. Also we kept IN signal constant and toggled EN. In any case this effect is observed. Digital levels of IN & EN signals are 0 to 3.3V.
In the literature we observed that such a high glitch in such a small time (we observed 100ns as pulse width) will be due to body snatching MOSFET usage. Please let me know whether such a effect is what we are observing.
Apologies for the delay in replying.
From the new plot you provided it looks more like a charge injection issue. Do you have any capacitance on your load? The Vout glitch is a function of the charge injection of the switch and the load capacitance. QINJ = CL × ∆VOUT (see datasheet fig 28.)
Also if you have a high impedance load you could consider the ADG1219 which has a lower typical charge injection of 0.1 pC.