High Side And Low Side Driver to Control Motor

Thread Starter

Beanz1114

Joined Nov 13, 2014
18
Hello good people of allaboutcircuits. I am quite new at circuitry so go easy on me. I was given a high side driver (UDN 2987x-6) and a low side driver (TLE 6225) to drive a 24Vdc motor (using both at the same time). I have done it according to the attached diagram and was told that I did it wrong, although I did get the motor to turn (I tested it out on a breadboard). I just have a couple of questions.

1)What is a high/ low side driver anyway? (Btw, I did a google search and nothing useful turned up)
2)What did I do wrong? My friend gave me a hint. It had something to do with pin assignments.
BTW the 5v from pin 1 of TLE comes from a microcontroller.
3)Can't I just use transistors instead? If so, then how?

Thanks!

Datasheets:
TLE 6225
http://html.alldatasheet.com/html-pdf/80187/INFINEON/TLE6225G/649/2/TLE6225G.html

UDN 2987
http://www.allegromicro.com/~/media/Files/Datasheets/UDN2987-Datasheet.ashx

Project1.PNG
 

Alec_t

Joined Sep 17, 2013
14,337
Welcome to the forum.
What is the full spec of your motor? The UDN chip can handle only 100mA per channel and the TLE chip can handle only 350mA per channel. Is that enough to cope with the start-up (i.e. stall) current of the motor (which is many times the normal running current)?
What is a high/ low side driver anyway?
Ask Google. Or read the datasheets. They will also indicate which pins do what. Input pins should not be left floating.
 

Thread Starter

Beanz1114

Joined Nov 13, 2014
18
Thanks Alec. I actually fed the input pin to a 5V power supply to emulate the 5v given off from a microcontroller. I wish I knew the motor's specs. I found it lying around in the lab and decided to use it. Lol.
 

Alec_t

Joined Sep 17, 2013
14,337
If you measure the DC resistance of the motor, that will enable you to calculate the likely peak current that the motor draws at start-up.
 
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