sharing power supply for analog and digital circuits for a CMOS image sensor

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hi,

im using a CMOS image sensor for a project. im using the same 3.3V
regulated supply for both of its analog and digital circuits. when
operated, sensor tends to reset itself when exposed to heavy light. (
im assuming its resetting it self, because when internal register
values are inspected, they give default values after bright light
exposure). if anny one has any such experiances please let me know. can
this happen becuase im sharing the same supply between both analog and
digital circuits?


thnak you
CMOS

 

[Joerg]

im using a CMOS image sensor for a project. im using the same 3.3V
regulated supply for both of its analog and digital circuits. when
operated, sensor tends to reset itself when exposed to heavy light. (
im assuming its resetting it self, because when internal register
values are inspected, they give default values after bright light
exposure). if anny one has any such experiances please let me know. can
this happen becuase im sharing the same supply between both analog and
digital circuits?

When I designed a CCD camera way back in the last century I also shared
power between digital and analog. After all, the "digital" phase driver
signals were going onto the chip so they had to be as clean as a whistle.

Unless something is mentioned in the sensor data sheet I believe a reset
upon too much exposure is not normal. Look at the supply rail with a
fast scope on AC and cranked up a bit. Do you see any spikes or dips on
there?

Regards, Joerg