What kind of digital
What kind of digital connection? What are you using as the output device? Most MCU’s can source/sink 25mA.
** It is for my version on of**
Two last quick question,
Two last quick question, with the ULN2003A, isn’t the output the opposite of the input ?
and can I use the darlinton arrays with no other components (resistors, diodes, caps) ? excluding the microcontoller and the device being controlled of course.
The ULN2003A works just the
The ULN2003A works just the same as 7 NPN darlington transistors, so if the input voltage is high, though corresponding output will be pulled low. Conversely, if the input is low, the output is not pulled high but simply left floating (no connection).
In the case of both the ULN2003A and the ULN2803a (the 8 channel version), you can drive them straight from almost any microcontroller. The resistors and diodes needed for them to function properly are built right into the package. The ‘3’ in the part names indicates that those models are built to work with 5V TTL/CMOS level parts.
Thanks!! I wonder how I got
Thanks!! I wonder how I got that idea that they were opposite
When you say pulled to "low", do you mean to ground or to the common emitter?
The common emitter is
The common emitter is designed to be connected to ground, make sure you get the datasheet and examine where all the protection diodes are connected if you plan on connecting the emitter to something else.
Well from this http://focus.ti.com/lit/ds/symlink/uln2003a.pdf
it seems that the emitter is not meant to be tied to ground but V, odd ? If this is the case it is perfect for my application,
but it contradicts what you and previous users have said. Why is it all so complicated…
I think you’re getting
I think you’re getting confused between the common emitter, and the common diode pins. The common emitter goes to ground, while the common diode normally goes to V+ for overvoltage protection on the outputs.
oooo thank you so much for
oooo thank you so much for that ! What was messing me up was the schematic from diptrace, the chis had a com pin and a ground pin so I assumed the com pin was the common emitter.
Well since the emitter is tied to ground this driver is useless in my case.
Thanks for your help in me understanding it!