VSP5610: not able to get proper count

VISHAL KALWANI

Intellectual 705 points

Part Number: VSP5610

I have connect my signal with ground in cds mode.

I am getting 100 counts difference.

I have configured in pixel clamp.

I have configured mclk to 1Mhz.

with shp_r=8

shp_f=16

shd_r=30

shd_f=42.

I have measure the waveform in ac mode. after cap that is afe input.I am getting this kind of waveform do i suppose to get this kind waveform.

if you want schematic please refer my previous question that i have asked.

over 6 years ago

0 Praveen Aroul over 6 years ago

TI__Guru 50036 points

Hi Vishal,

Based on your captured image, we are inferring that SHP start at around 200ns (near first vertical marker), pixel clamping active for 80 ns (SHP/2). Thus assumed SHP phase start at ~200ns and end at ~360ns. Similarly, SHD start at around ~660ns. These numbers align with your programmed configuration.

Due to the switched cap architecture of CDS, switching is expected at the start of SHP, SHD and the magnitude is difficult to quantify.

100 count difference is expected to be canceled using offset blanking feature of the device as explained in the datasheet.

0 VISHAL KALWANI over 6 years ago in reply to Praveen Aroul

Intellectual 705 points

Offset blanking did you are saying of offset correction.I am not able to find offset blanking in datasheet.But offset correction is there.

0 Praveen Aroul over 6 years ago in reply to VISHAL KALWANI

TI__Guru 50036 points

Vishal,

Yes, that is correct. I was referring to the offset correction DAC.

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VSP5610: not able to get proper count