Constant current step-down driver ?

[Tech]

I need a constant current driver to power different LDs from different batteries.
Input voltage: 2.8-4.2 V (wider is better)
Output voltage: 0-2.2 V (may be not adjustable)
Output current: 0-1 A adjustable (0-2 A is better)

It should be a highly efficient switching driver with small form factor. I'm going to incorporate such drivers into pointers.

Can anyone suggest such a driver for purchase ?

 

[Hiemal]

Well, actually almost all boost converter drivers would work fine for this... It's just the matter of being able to supply enough current.

Try looking at a Flexdrive, or maybe some of the other drivers LPF members have made. They should all be great for what you're looking for.

 

[Tech]

Micro Flex Drive V5 Manual: For powering high current (>500mA) 1.8V diodes, a series shottky rectifier is required so that the output voltage is 2.2V or greater.

This is not suitable for my 808nm diodes which usually have voltage below 2.2V at high currents.
It doesn't seem to be a good idea to connect a rectifier in series to loose power and to produce heat.

Any other suggestions for driver models ?

 

[millirad]

There is a member here HIMNL9, who could design what you want in his sleep. He's very knowledgeable about electronic circuits and has guided me through a few problems. You could PM him if you get stuck.

 

[foulmist]

There are a lot of step down current regulators already available... no need to re-invent the wheel.

This is one is great, and can go up to 2A
http://www.dealextreme.com/p/18v-5w-cree-circuit-board-for-flashlights-16-8mm-5-5mm-26110

 

[Tech]

While there may be a lot of drivers available, I haven't found one that fits my specs.
The proposed drivers for LEDs do not provide adjustable current. They do not meet my Input voltage criteria (I want to use non-rechargeables as well).

I want to build efficient lasers with adjustable power. I just can't believe there are no products on the market that meet my specs.

 

[foulmist]

While there may be a lot of drivers available, I haven't found one that fits my specs.
The proposed drivers for LEDs do not provide adjustable current. They do not meet my Input voltage criteria (I want to use non-rechargeables as well).

I want to build efficient lasers with adjustable power. I just can't believe there are no products on the market that meet my specs.

I am pretty sure that driver can operate from 1 Li-Ion or 3x1.2V for powering an IR diode. and the current is adjustable via resistor.. you just swap it with the appropriate value. I = V/R , where I = 0.25/R I have few at hand and they sure work great.

 

[Ghostchrome]

While there may be a lot of drivers available, I haven't found one that fits my specs.
The proposed drivers for LEDs do not provide adjustable current. They do not meet my Input voltage criteria (I want to use non-rechargeables as well).

I want to build efficient lasers with adjustable power. I just can't believe there are no products on the market that meet my specs.

Use different drivers for different lasers? Why the need to use the same driver in every laser you make?

 

[Tech]

When constant current is provided, you can always use the same driver for any LD of similar type/wavelength.
I only need a driver for 808nm LDs which usually have 1.8-2.2V voltage range. I do not demand the same driver to work with any other LDs.

 

[Ghostchrome]

Ah ok, I was thinking that you needed the same driver for a bunch of different diode types.