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I'm trying to build a motor driver which can supply ~3A per motor. Only cheap IC I could get my hands on was L298, so I decided to parallel its channels. But for some reason that I can't understand (I'm merely an amateur hobbyist), L298 and its diodes are getting too hot in just a matter of seconds.

I'm using a 12V (max 40W) power supply for my circuit, and its reduced to 0.95V when I check VCC/GND pins (how is that even possible ?)

This is my PCB design.

47uF capacitors,

1N5819 diodes,

L298N

enter image description here

Edit: Schematics enter image description here

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  • \$\begingroup\$ Can you please post your circuit schematic diagram? Not everyone will have the luxury of time understanding your issue by mapping PCB traces and pin connections. \$\endgroup\$
    – shimofuri
    Nov 30, 2012 at 12:55
  • \$\begingroup\$ I suspect you have a short somewhere, or one of your diodes is the wrong way round. Your silkscreen layer is a bit mangled and one of your labels is upside down.. \$\endgroup\$
    – pjc50
    Nov 30, 2012 at 12:56
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    \$\begingroup\$ What's a L298? What's your circuit? It should have been obvious that you need to link to the datasheet and provide a schematic. \$\endgroup\$ Nov 30, 2012 at 13:15

1 Answer 1

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You haven't labelled + and - on your battery!

Assuming that battery pin 1 is positive, because it's connected to VS of the L298, then your diodes are the wrong way round in the schematic.

Edit: the 0.9V is exactly as expected, as that's the forward voltage of the diode. You're sinking the full current of your power supply through a diode and the L298.

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    \$\begingroup\$ Your PCB seems to contradict your circuit diagram in this all-important aspect. The PCB seems to be OK. \$\endgroup\$ Nov 30, 2012 at 13:58

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