OPT3101: Using RED Laser diode instead of LED

hyeongjin jang

Prodigy 50 points

Part Number: OPT3101

Hi,

Could you please tell me whether the following RED Laser diode can be used instead of LED which is used on OPT3101EVM ?

How can I control the illumination currrent to 25mA ~ 30mA?

Best regards,

over 5 years ago

0 Alex Bhandari-Young over 5 years ago

TI__Mastermind 25845 points

Hi,

Current can be set on OPT3101. It is a 10MHz modulated signal. Regarding using a red laser diode you would want to check eye safety but if the diode meets switching time requirements then it can be used. Please refer to the illuminator selection section of our system design guide online.

Best,

Alex

0 hyeongjin jang over 5 years ago in reply to Alex Bhandari-Young

Prodigy 50 points

Hi Alex,

These are my questions.

1. I'm trying to output a class 1 laser of 0.39 mW so I want to know how to control the current in the TX port.

2. Should I use a crystal of 10 MHz instead of a crystal of 4 MHzin EVM?

3. Where can I check out your design guide?

Thanks,

Hyeongjin

0 Alex Bhandari-Young over 5 years ago in reply to hyeongjin jang

TI__Mastermind 25845 points

Hi,

1) You can control directly with OPT3101 as your would an LED given the max current, modulation signal, etc. from OPT3101 will power the diode correctly. If not another option is to put a driver in between and have driver take it's signal from OPT3101.

2) OPT3101 generates the 10MHz from an internal clock. Please refer to the datasheet for more details here.

3) design guide: http://www.ti.com/lit/ug/sbau305a/sbau305a.pdf

other guides and info: https://e2e.ti.com/support/sensors/f/1023/p/815766/3019009

Best,

Alex

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OPT3101: Using RED Laser diode instead of LED