Nonlinear PGA in CMOS Image Sensor

[E-goe]

Hi,

For a new project we are trying to increase the dynamic range of the CMOS image sensor by using 2 PGA's. One with a low gain and one with a high gain. The low gain PGA will be used for high illuminant scenes and the high gain PGA will be used for the low illuminant scene.

So I need a circuit/ideas/reference to papers, which describes a circuit which calculates the minimimum of the output of the 2 PGA's. The minimum of both signals will be used and converted with an 10bit ADC. By this we compress the scene and we can capture higher dynamic range scenes.

Any suggestions/comments references to papers are welcome

Thanks,
E-goe

 

[fanatic]

actually, what u need may can be done by a sample & hold stage, let this stage have a programmble gain

Hi,

For a new project we are trying to increase the dynamic range of the CMOS image sensor by using 2 PGA's. One with a low gain and one with a high gain. The low gain PGA will be used for high illuminant scenes and the high gain PGA will be used for the low illuminant scene.

So I need a circuit/ideas/reference to papers, which describes a circuit which calculates the minimimum of the output of the 2 PGA's. The minimum of both signals will be used and converted with an 10bit ADC. By this we compress the scene and we can capture higher dynamic range scenes.

Any suggestions/comments references to papers are welcome

Thanks,
E-goe