Other Parts Discussed in Thread: TPS62087,
I am using the TPS62087 (1.8V fixed version of TPS62085) in a design with a number of other TPS62085. The input voltages are all 3.3V. The outputs of the TPS62085's are 1.1V, 1.2V, and 2.5V. The outputs voltages all look clean EXCEPT for the TPS62087. It has a sawtooth noise 50mV pk-to-pk at about a 2.5kHz frequency. There is very little load on the line in this image, and as we increase the load on the 1.8V line, the frequency increases, but the pk-to-pk noise remains about 50mV. We have seen this on 2 separate boards.
The circuit is set up exactly like the application circuit using a .47uH inductor, a 22uF output cap, and a 10uF input cap.
