Voltage specs for 650 nm TTL laser diode

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pkeh
 
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Voltage specs for 650 nm TTL laser diode

Post by pkeh »

I have a question about the TTL Laser Diode - 5mW 650nm (product ID # 1056 ).
https://www.adafruit.com/product/1056

Can I use a 3.3 V TTL voltage to turn the laser on/off instead of 5 V ?

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adafruit_support_mike
 
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Re: Voltage specs for 650 nm TTL laser diode

Post by adafruit_support_mike »

We don't have a datasheet for them, so that falls under the heading of 'unspecified' where it's safest to assume whatever is least convenient.

At worst, you can control the laser's input with an inverter made from an NPN transistor. A 3.3v signal is more than enough to control an NPN.

In practical terms, even 5v-CMOS will recognize 3.3v input if you run it from a 4.5v supply rather than 5v. The standard thresholds are 0.7VCC and 0.3VCC.

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