ULN2803A: Use for low current

Fernando Cavallero

Prodigy 30 points

Part Number: ULN2803A

Hello

I need to know if the ULN2803A is suitable for low current applications.

I want to use it in TTL application with 0/5v at the collector.

What resistor value do you recommend to put between the collector and +5Volts ?

Thanks

over 5 years ago

0 Shreyas Dmello over 5 years ago

TI__Mastermind 32650 points

Hi Fernando,

ULN2803 can be used for lower current applications but I do not know what you exactly mean by "low current".

The peak current per channel for this device is 500mA. So any current lower than that should be fine.

If you are running from a 5V source, would 50mA be considered as "low" current for you? In that case 100Ohms is all you need.

0 Fernando Cavallero over 5 years ago in reply to Shreyas Dmello

Prodigy 30 points

What I mean is that I'll drive a high impedance device which must recognize logic 0 and 1.

So I will using the ULN feeding voltage instead of it's current capability and I must be sure the Darlington Vce reach closest to TTL 0 volts with a pull up resistor.

Thanks

0 Shreyas Dmello over 5 years ago in reply to Fernando Cavallero

TI__Mastermind 32650 points

Hi Fernando,

I think it will still work. On the other hand do you require the 8-ch integration? The TPL7407LA is 7-ch MOSFET based device that is functionally similar.

I think it might be a better fit for your application.

0 Fernando Cavallero over 5 years ago in reply to Shreyas Dmello

Prodigy 30 points

Thanks!

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ULN2803A: Use for low current