Possible Improved CMOS Image Sensor.....

[Anhar_Miah]

Hi Bob,

Had a look at the MICROCHIP SAR A/D datasheets for all the MCP3xxx series, looks like that the maximum sampling was only 2.8 MHz (200 ksps), thats no where near the 100 MHz we would require.

EDIT:

Now the AD7623 from DigiChip looks more promising @ 1.5 Msps, available in 14/16 Bit ADC

 

[BobDiaz]

Hi Anhar Miah,

In general, most Successive Approximation A/D Converters max out at around 100,000 to 200,000 samples per second. Way too slow for video.

With all the links and all the information, it's easy to miss a key link:

VERY High Speed (40M samples per second) Successive Approximation A/D Converter : http://www.eecs.umich.edu/~mpflynn/D...orts/Huang.pdf

If I'm reading the paper correctly, the converter would do 40 million samples per second. In order to speed up the rolling shutter 100 times, the sample rate only had to be around 6 million samples per second.

With image sensor using something like the AD7623 from DigiChip @ 1.5 million samples per second, the rolling shutter would be about 25 times faster. That would be an improvement...


Just a little more on the numbers ... I hope you don't mind this...

Time = 1 / Frequency

100 MHz = 0.1 GHz

1 / (1 GHz) = 1 x 10^-9 seconds

Thus:

1/ (0.1 GHz) = 1 x 10^-8 seconds



Best Wishes,

Bob Diaz

 

[Anhar_Miah]

Just a little more on the numbers ... I hope you don't mind this...

Time = 1 / Frequency

100 MHz = 0.1 GHz

1 / (1 GHz) = 1 x 10^-9 seconds

Thus:

1/ (0.1 GHz) = 1 x 10^-8 seconds



Best Wishes,

Bob Diaz

D'oh I can't believe I missed that! I've just re-re-re-checked forgot to shift two decimal places (because its 100 not 1)

yes we are both right, we got the same value But just shifted different decimal places...

you known this reminds me of the time me and my best friend (who is a trainee medical doctor) we was debating for more than three hours before we realised we are arguing for the SAME side!

 

[BobDiaz]

Anhar Miah,

It was a little slip up, so don't feel bad.

It could be worse, like the video of Barack Obama saying he's been to 57 states in the USA. ... OK, I know he was tired and was thinking, 50 States - 3 = 57 ... "I've been to 57 states..."

We all have those days, but in Obama's case, it ends up on YouTube.

Best Wishes,

Bob Diaz

 

[Anhar_Miah]

Very true Bob!

I'm youtubing it now!

P.S cheers for the paper