I have two LTC2757 DACs. Each has an LT1001 transimpedance amp. I'm generating a square wave with each. The square waves have 0.2V amplitude. I update the DAC values at 100 Ksps, regardless of whether there is a change needed in the output voltage. The square waves are out of phase. Here is a screenshot of the moment when one of the outputs goes high:
1. The glitch amplitude here is ~5mV. The datasheet (pg 7 "settling full scale step") shows an amplitude of ~300 uV for a 0 to 10V step. Why are my glitches so much bigger?
2. The glitch amplitude on the green channel gets smaller when the blue channel goes high. Why? The DACs share a data bus, power supplies, and reference.
made more clear
[edited by: justinis at 9:00 PM (GMT 0) on 19 Sep 2019]