Other Parts Discussed in Thread: LMK03318
Hello,
We have strange behavior looking that output frequency can float and not stable.
We tested some frequencies (30, 50, 80, 100, 125 MHz) and it's clearly viewed that output signal has deformations relatively on working clocks.
We using default ADC settings after reset (bit 0 in register 6).
In general we using LMK03318 as clock source. Default frequency - 125 MHz. The signals below was oscilloscoped at 40.3 MHz because we use 200 MHz oscilloscope in this test. 125 Mhz leads to the same forms of signals, but no so straight due to oscilloscope limits.
Picture 1: ADC clock, FCLK (pins 48, 49)
Picture 2: FCLK, DCLK (3x multiplied)
After cold start devices are working sometime and passed internal tests (pattern generation and integrity check in cycle). But while devices warmed up to 40 C ADC working unstable, as described above.
We got this behavior at 3 boards from 13 at all. Another 10 boards working stable all time.
What can leads to it? May be overheating, incorrect mounting or something else?