OPT8241: Higher dynamic range for the illumination power

Jongho Lee

Part Number: OPT8241
Other Parts Discussed in Thread: TPS2559

Hi,

I need high dynamic range for the illumination power, but it seems that I can control only from 48% to 100% of maximum illumination power.

Is there any solution to increase dynamic range for the illumination power like from 10% to 100%?

Thanks.

over 7 years ago

0 Subhash Chandra Sadhu over 7 years ago

TI__Expert 3800 points

Hi,

The illumination power limits are because of the IC TPS2559. Unfortunately, the way to expand the minimum and maximum range is to redesign the hardware with a different current source.
Please refer to the illumination driver app note to see suggestions for current source implementation: www.ti.com/.../sbaa209

Regards,
Subhash

0 Subhash Chandra Sadhu over 7 years ago in reply to Subhash Chandra Sadhu

TI__Expert 3800 points

One way to have a higher dynamic range is to shunt some of the current. You would have to "bleed" some of the current coming out of TPS2559.
If you shunt 0.72A from the output of TPS2559 to ground, you would have achieved your objective. Please note that this will void the camera's eye safety specification and it will also cause the camera to heat up.

Regards,
Subhash

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OPT8241: Higher dynamic range for the illumination power