Other Parts Discussed in Thread: AMC3301
I ordered 3 pcs of AMC3301EVM evaluation boards in 08/2020.
I have found that the outputs of these boards oscillate. The problem is similar in all of these boards.
Here is an oscilloscope screen capture:
AMC3301EVM's INP terminal driven by signal generator with 0Vdc. INN terminal grounded. Power supply's minus terminal grounded.
Math 1: VDD - GND (power supply voltage)
Ch 3: Voltage between board INP and INN.
Ch 7: OUTP
Ch 8: OUTN
Math 2: OUTP - OUTN
As it can be seen, the outputs oscillate. There is no excitation at the input nor in power supply voltage at the same frequency.
Ch 7 frequency measurement "Meas 8" happened to be 1 MHz at the instant this above capture was taken. Most of time it was ~312 kHz.
Here are the package markings of ICs used in these boards:
Here is the board used in these measurements:
Is there a design flaw in these ICs or what is going on?