laser diode driver

[badger1666]

can any one help
i am looking for a laser diode driver ciruit or complete module
it must have ttl modulation and be adjustable up to 300ma or close to as possible dosnt matter if its a bit more than 300 ma i want to drive a hi power dvd burner diode
thanks
chris green

[450nm]

I have been in the hobby less than 3 weeks. I'm currently building my first driver using the die4drive pcb from Robin Bowden. If you can handle the smd's then go for it.

Regards - Dave

[p1t8ull]

Indeed... Robin da man:

http://www.die4laser.com/dvd-rec/Die4Drive.htm

He can supply either a bare board, or fully assembled and tested.

[carmangary]

Some hints on the die4drive boards... several of the components can be obtained for free by asking for samples from component vendors. I built a couple and got the diodes and opamps for free.

[badger1666]

thanks guys it looks just what i want i have emailed him so i can buy one
looked at the web site and every thing about that driver ,theres a pot to set the drive current but how do you set the output voltage for the laser diode that i want to use? can anyone help
thanks
chris

[carmangary]

You don't set the voltage. You set the current.

[badger1666]

hi
i know you have to set the current i have a diode that requires 2.9 volt@ 200ma so if it got 5volts going into the driver how do you get 2.9v out?
thanks

[450nm]

This is the Farnell parts list. It worked out cheaper to buy enough components for 2 drivers.

BOM with Farnell part numbers

1 818-7622 LMV116MF OP-Amp U1
2 9843612 BAV-99 D1,D2
2 933-2383 1k 0805 Resistor R10,R11
2 718-520 470pF 0805 Capacitor C1,C2
1 1086793 100nF 0805 Capacitor C4
1 933-2499 1k2 0805 Resistor R5
1 933-2944 2k7 0805 Resistor R4
2 933-2391 10k 0805 Resistor R7
1 933-3258 470R 0805 Resistor R8
1 933-2820 22k 0805 Resistor R3
1 933-2375 100R 0805 Resistor R9
1 8660158 IRLR3105PBF Mosfet Q1
2 * 514755 1k Bourns 3314J Pot R1,R2
1 113-5202 150u 10V 50mR TPS Tant C3
1 923-9669 1R PRC201 Resistor 1% R12

* Value dropped from 10k to 1k for better adjustment linearity.
If you need 10k input impedance use the 10k POT.
10k Bourns 3314J POT is part no 514779

[carmangary]

You can't set both current and voltage because one will dictate the other.

V= I * R or I = V / R

With laser diodes you don't worry so much about voltage other than making make sure your P/S is capable of supplying enough.

hi
i know you have to set the current i have a diode that requires 2.9 volt@ 200ma so if it got 5volts going into the driver how do you get 2.9v out?
thanks

[450nm]

Well I got all of the bits for the die4drive today. Took me just 4 hours to put it together and it worked a treat.

Just need a decent diode now.