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Topic: amplifying the output channels of a TLC5940 (Read 1 time) previous topic - next topic

davivid

I need to amplify the output channels of a TLC5940 upto 12v @ 5A.

Are there any off the shelf products that will do this?

dc42

You could use one TIP107 PNP darlington pair per 5940 output pin. Configure the 5940 to sink about 20mA per output. The TIP107s will drop up to about 2 volts, so if the load needs 12v then you may need a 14v supply. If it is for driving LEDs then you will need a series resistor or resistors between the collector and the LED, unless the LED modules are already designed to work from 12vDC.
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davivid

Ok thanks. Yes for driving lengths of LED strips, rated at 12v with a max current of 5amps.

Similar to this:
http://www.ledlightszone.co.uk/led-tape/55-flexible-led-strips-non-waterproof-72w-30pcs.html

Since health and saftey may be an issue - are there products/modules already designed for this?


davivid

#3
Aug 24, 2011, 11:26 am Last Edit: Aug 24, 2011, 01:57 pm by davivid Reason: 1
Do I simply supply ~14v to the Emitter, connect the output of the TLC5940 to the Base, and ground the LED from the Collector?

Also how would I best compensate if the power supply is 15v?

CrossRoads

Check the TLC5940 datasheet - I believe it needs to sink at least 5mA on the output pins to operate stably.
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