TLC59731: Need current source rather than current sink version

Scott Brusaw

Part Number: TLC59731
Other Parts Discussed in Thread: TLC59108, LP55231

The WS2801 has been discontinued. We used that LED driver in our previous models. We're now designing a new model and need a new driver. I have the TLC59731 working, but it can't sink enough current for what we're doing. Is there similar part that is current source (to drive a transistor), or is there a way to have the TLC59731's OUT pins drive transistors that will allow higher currents? Our maximum draw is 265mA per channel.

over 4 years ago

0 Hardy Wu over 4 years ago

TI__Genius 12915 points

Hi Scott,

Sorry that for such single wire data interface, our device all only have up-to-50mA output current.

0 Scott Brusaw over 4 years ago in reply to Hardy Wu

Prodigy 220 points

Output current is what I need. The device sinks the current. Is there a circuit that can drive a transistor with the OUT pin?

0 Hardy Wu over 4 years ago in reply to Scott Brusaw

TI__Genius 12915 points

Hi Scott,

Could you help also advise some other requirements like channel number and dimming ratio?

0 Scott Brusaw over 4 years ago in reply to Hardy Wu

Prodigy 220 points

3+ channels, single or dual wire, current source rather than current sink

Preferably 8-bit (0-255) dimming ratio

0 Hardy Wu over 4 years ago in reply to Scott Brusaw

TI__Genius 12915 points

Hi Scott,

Most of out device cannot provide 265mA per channel output. I think TLC59108 with 8 channels and 120mA maximum output current may could be used. You can parallel 2 channels to support up to 240mA.

0 Scott Brusaw over 4 years ago in reply to Hardy Wu

Prodigy 220 points

I'm not asking for a channel output that can drive 265mA. I'm asking for a channel output that can drive a transistor, which can handle the 265mA.

0 Hardy Wu over 4 years ago in reply to Scott Brusaw

TI__Genius 12915 points

Hi Scott,

Could you help to advise the output current requirement for IC? I do not know your transistor spec so do not know how much current can drive 265mA.

If 50mA of TLC59731 cannot be enough, TLC59108 have higher current per channel as 120mA.

For current source device, our device only have up to 25mA output capability, like LP55231.

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TLC59731: Need current source rather than current sink version