Cancellation of Ambient light.

Hi Hardik,

the simplest way is shielding.

Can you tell more about your application? What light are you measuring? How the schematic look like?

Kai

Hello Hardik,

The LMH32401 has an ambient light cancellation feature. This is done using the DC servo loop method which you can find a few details on here:

https://e2e.ti.com/blogs_/b/analogwire/archive/2013/02/22/correcting-dc-errors-in-high-speed-amplifier-circuits

https://e2e.ti.com/support/amplifiers/f/14/t/225353

You can also use the first circuit found in the linked E2E thread as a simpler AC coupled transimpedance circuit. However, this circuit design comes with its own disadvantage of a non-constant bias on the photodiode.

Best,

Hasan Babiker

Hi Hasan,

Thanks for your response.

Will try to implement and check the result.

Is it possible to have a transimpedance amplifier which can have inbuilt feature of Ambient light rejection feature?

My application may need to work in sunlight with specific rate of light blinking at some specific frequency.

Please share your inputs.

Thanks

Hardik Raval

Hello Hardik,

The LMH32401 is the only part that I am aware of with the ambient light rejection feature. The methods shown in the e2e posts were for a typical amplifier in a trans-impedance configuration. 

Best,

Hasan Babiker