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Description: 8 Darlington Arrays in 18-Pin DIP Package part # ULN2803A. Perfect for running relays and high-power devices up to 500mA and up to 50V!
Resources: Nuts and Volts article on Driving High Current Loads
Documents: ULN2803A Datasheet
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In the description, ADD the word transistor so it shows up when you search for a transistor.
I feel like a lot of times I’m never satisfied with Sparkfun search results. Maybe I’m spoiled by google.
Does this come with a housing to be soldered on to a PCB? Do you sell them?
ULN2803 current: shared or per output?
Hello, one question. ULN2803’s datasheet says “500mA output”.
So my question is: Those 500mA are:
a) per each single output? (500mA each output, so paralleled the 8 outputs will draw 500mA*8=4000mA?)
b) shared per the whole chip? (500mA/8 outputs= 62,5mA per output)
If I read the data sheet correctly, the rating is per output.
There’s a line in the datasheet, though, that reads “Total substrate-terminal current … −2.5 A,” which leads me to believe that you can switch up to 500 mA on each pin, but can’t sink more than 2.5 A total. So if you want to switch 4 A continuous, you cant do it with (just one of) this chip, but if you had 8 loads of 500 mA each, and didn’t turn more than 5 on at a time, you’d probably be OK.
Can I drive these directly from any arduino? (5v)
And how is input mA related to output current/voltage?
Are these capable of switching fast enough to allow pwm?
I’m new to reading datasheets…
According to the datasheet, the “typical” Low-to-High transition takes 130 ns. H-to-L is typically 20 ns. Round up, call it 200 ns, and you can cycle these darlington pairs at about 5 MHz. If you’re doing PWM for LEDs, then you would typically use a mere 100 Hz.
Sorry if this is a dumb question, but I’m new with this stuff. If I connected the common pin to ground would I be able to connect each of the collectors to ground and drain current?
Will these work for switching high-power, 3V LEDs from a 5V control source?
I use mine with the PWM pins on my Arduino Uno to control an RGB LED strip, so I would think you would be alright as long as you don’t exceed 500mA.
Anyone know if I can drive this directly off 3.3V? Works great with 5V, and the pinout lines up perfectly with the Pro Mini.
Did you ever get this working. I need the same
This worked woooonderfully, btw. So, so, so easy to just solder the Darlington directly to the Pro Mini. Used this configuration in 3 projects so far, and stocking up for more.
Datasheet says 3 volts is required to sink 350 mA.
Can this be used to drive motors?
never mind… It works perfectly (as we all knew it would. this is Spark Fun after all!!)
It can drive 500 mA per channel, and the outputs/inputs can be connected together to switch more current.
I think if you use it as a high-side, you’ll end up getting latching like a thyristor…. you cant turn it off.
You need PNP for high side stuff. I’m pretty sure this is NPN
I dont think you can use these as a high-side switch. If the load is any bit reactive, you’ll have latching problems…I think… most chips that are high side are marketed as exclusively high-side
Can NPN darlingtons used as a high side switch? If I connect the collector to 5V and the base as well, what will be the emitter voltage? <br />
According to the datasheet Vce(saturation) is 1V, so would that mean that at the emitter the voltage is 4V?
do you have eagle library for this too??
Could anyone give me some advice whether I could use this with a TI Launchpad to drive “blocks” of LEDs in parallel. Looking to make a table with LED effects and so just want to be able to switch between 6-8 blocks of parallel LED arrays. Problem is, TI output pins are only 3.3V…none of the LED arrays require more than 500mA and have voltages of say 12V.
Faster, cheaper, smaller, better, right? The SN754410 Quad Half H-Bridge is just that. Capable of driving high voltage moto…
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