OPT3101: Using VCSEL instead of LED

Sadanori Kato

Part Number: OPT3101

Hi,

Could you please tell me whether the following VCSEL can be used instead of LED which is used on OPT3101EVM ?
So, please allow me to discuss offline if necessary.

https://www.mouser.mx/ProductDetail/Finisar/I940-G2356-NBC-A2C?qs=%2fha2pyFaduhCMNzaM6F1m4VCiKN%2fw9OZg19eIoMHMIzPSVmiiaGJoDR7eYQ8m5Zw

Best regards,
Kato

over 6 years ago

0 Alex Bhandari-Young over 6 years ago

TI__Mastermind 25895 points

Hi Kato,

VCSEL can be used but has some additional considerations. Please refer to the system design doc. Sections 6.1.2.2 and 6.2.5 are important as well as some other sections that cover use of lasers.

Best,

Alex

0 Sadanori Kato over 6 years ago in reply to Alex Bhandari-Young

Guru 36540 points

Hi Alex-san,

Thank you for the comment.

The maximum built-in illumination driver current is 173.6mA, so isn't enough.
Therefore, OPT3101 cannot directly drive above VCSEL.
Could you please share the information to me if you would have the reference design with VCSEL ?

Best regards,
Kato

0 Alex Bhandari-Young over 6 years ago in reply to Sadanori Kato

TI__Mastermind 25895 points

Hi Kato,

Yes, if a higher current is needed then you will not be able to drive it directly. The options here are OPT3101 can drive an external driver circuit or if you are able to find a VCSEL that requires less current then OPT3101 might be able to drive directly.

Unfortunately, we do not have any reference circuits for using lasers.

Best,

Alex

0 Sadanori Kato over 6 years ago in reply to Alex Bhandari-Young

Guru 36540 points

Hi Alex-san,

Thank you for the comment.

Could you please confirm whether OPT3101 can drive an external driver circuit directly ?
So, I will try to find whether other VCSELs can meet the current requirement.

Best regards,
Kato

0 Alex Bhandari-Young over 6 years ago in reply to Sadanori Kato

TI__Mastermind 25895 points

Yes. You just need to make sure the driver is fast enough to do the 10MHz square wave from the OPT3101.

Best,

Alex

0 Sadanori Kato over 6 years ago in reply to Alex Bhandari-Young

Guru 36540 points

Hi Alex-san,

Thank you for your quick response.

I understood.

Best regards,
Kato

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OPT3101: Using VCSEL instead of LED