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Programmable Constant Current source for IRDA Led

Hello,

I am looking for a programmable Constant Current Source to drive some IR Leds through a MCP2122 Encoder/Decoder ic. Ideally, I would like to be able to adjust the current via a SPI/I2C or similar, to enable automatic IR range. As this is an IRDA encoded output, I can't use a PWM Output current source.

Details:

Supply 5V:  Output voltage needs to be > 2V to power 1 Led at a time (8 total multiplexed)

Constant current needs to be programmable between 0 - 100mA.

Output to be linear, not PWM.

A method of varying the output current by means of a microcontroller. SPI/I2C or a voltage input. Not PWM.

Space is tight, hence integrated solution preferred.

I have scoured the net, and only found 1 part, which is near obsolete and also expensive.

Any advice greatly appreciated

Regards

John