High output current modulation from low analog current input

Hello,

My goal is to get an output current DAC that can generate up to 400mA, very fast and at low power.
Since getting such current out of a DAC is not recommended, I want to use an external high speed high current op-amp to generate the wanted current.

What I have now is:
- A DAC that can generate from 1 to 5mA.
- A 400mA current amplifier.

Does anyone know a good idea to have an output current that can be from 0 to 400mA, by using as "modulating" input the 1-5mA current from the fast DAC?

I am looking for any good ideas and don't hesitate to ask if you have any question.

Thank you,


Meach

How about a 400ma current source using an op amp and fet, driven by your 1-5ma source?

Use the source current to generate a 1-5v dc signal to drive the 400ma current source?

Thank you for your answer Chippie. But I am not sure I understand it
Can you be a bit more specific about what you said?

Thank you,


Meach

Turn the 1-5 ma current into a voltage using a resistor, this is then used to control a current amp using an opamp with a fet..

Have a Google for op amp current source, there are plenty of examples and its easier than me trying to attach a sketch of one...