Hi team,
My customer is using DDC114 for photodiode, and when measuring with a fixed range, it shifts by about 20 to 30 counts.
A photodiode connected to IN1 to IN3. IN4 is unused (open state). AVDD = 5V, VREF = 4.096V, DVDD = 3.3V, resolution 20bit, CLK_4X = L, Hispd / Lopwr = H
He found that It is not caused by fluctuations in externally incident light or range switching. Once the power is turned off, it will return to its original state.
It occurs in the internal range 7 (87.5pF). The amount of shift varies, IN1 and IN2 have almost the same shift amount, and IN3 has a slightly larger shift amount.
Both A-side and B-side occur at the same timing and the same shift amount. And it occurs even in a light-shielded situation. Even in that case, the shift amount is almost the same as when the light is incident. In most cases, it changes from small to large, but sometimes it returns to the small value before the shift.
Could you explain why this happens and how to solve this?
Best,
Zeming
