Maximum transient current through a transistor?

[dsegel]

I have an application where I want to switch a path through a transistor that will be +/-20V and may go up to 2A. The current will only be flowing for about 100ms, with at least 1 second in between. I'm currently planning on using a ULQ2003A transistor array because I need 6 of them to control 6 devices independently.

My question is, how do I know if this will work, or if I'm going to blow up the transistors? The datasheet for the ULQ2003A is here: http://www.mouser.com/ds/2/389/ulq2001-957368.pdf

If necessary I could lower the voltage a bit.

[Zero999]

The data sheet specifies a peak current of 600mA.

Another issue you may have is that the Hfe of the transistors might not be high enough to give a low enough on voltage. The transistor might operate in its linear region acting like a current sink, dropping most of the voltage, leaving very little for the load.

[BigBoss]

I have an application where I want to switch a path through a transistor that will be +/-20V and may go up to 2A. The current will only be flowing for about 100ms, with at least 1 second in between. I'm currently planning on using a ULQ2003A transistor array because I need 6 of them to control 6 devices independently.

My question is, how do I know if this will work, or if I'm going to blow up the transistors? The datasheet for the ULQ2003A is here: http://www.mouser.com/ds/2/389/ulq2001-957368.pdf

If necessary I could lower the voltage a bit.

If you application is purely to switch a signal during 100ms, I recommend you to use Switching MOS Transistors.They have more current carrying capability and higher dissipation capacity on them.
http://www.onsemi.com/PowerSolutions/product.do?id=FDMQ8403
It's got 4 channels.

[dsegel]

Yeah, i just read up on Hfe and realized it might be a problem.

I saw the 600mA spec, but didn't know if that applied to transient events.

[dsegel]

Thanks, I'll check it out.

[danadak]

Google "octal power driver", a number of alternatives. Darlingtons suck because they
have such high Vcesat.


Regards, Dana.