LM3429: Laser Diode Driver to 6W recommendation

Andrew Buckin

Part Number: LM3429
Other Parts Discussed in Thread: LMH13000

Tool/software:

Hi, advise a modern driver for a 6W Laser. I want to do engraving at home. Forward voltage of the diode is 5V so that the current can be adjusted from 1A to 5A. I want to power it all from USB-C.

If there is a possibility of I2C control - it will be very good.

Thanks for the help.

Andrew.

5 months ago

0 Daniel Louis 5 months ago

TI__Expert 5750 points

Hi Andrew,

I apologize for the late reply.

Why do you need I2C? Are there certain diagnostics that you need? Most designs can be accomplished with purely analog solutions.

What is the expected input voltage from the USB-C? None of our parts have I2C, so I am taking the liberty of moving this to the "Display Lighting" (DL) group.

Ideally you'll use a buck and you will have better dynamic control with SPI. TPS92520 and TPS92682 both have SPI interface. Please let me know if you have any other questions.

Best,
Daniel

0 Andrew Buckin 5 months ago in reply to Daniel Louis

Expert 2130 points

TPS92520 interesting chip. is it possible to connect channels in parallel? i need more than 1.6A. for 5W laser i need 3A current.

Boost is not suitablel. Buck-boost or buck.

I did an experiment with TPS55287Q1. to test the laser, I really liked it. But. soft start.

Best,

Andrew

0 Daniel Louis 5 months ago in reply to Andrew Buckin

TI__Expert 5750 points

Yep! A lot of our customers connect these devices in parallel.

Here is the schematic for the TPS92520 configured as a 2 channel Buck, each channel can output 1.6A. This can be controlled as a 2-phase device to distribute the needed currrent
www.ti.com/.../sluucc4a.pdf

I'm not sure if you need to control a motor, but the TPS92544 could be a solid option if needed. It has both a boost and a 2A buck.
https://www.ti.com/lit/ds/symlink/tps92544-q1.pdf?ts=1744221499410&ref_url=https%253A%252F%252Fwww.google.com%252F

This is another solution that is commonly implemented. I often see this with two TPS92520 ICs configure in parallel:

Please let me know how I can further assist you.

Best,
Daniel