L298 stops

Hi all
We are using a L298 IC to control DC motors from a uControler. The problem is that it suddnly stops after a short run and became very hot.
We attached a heat sink to cool down the chip but it didn't solve the problem. In the datasheet there is a Diode bridge that we didn't put in the circuit. Any one have any idea about the problem.
Ahmed
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"ahosyney" wrote

hot.
Did it get hot _after_ it stopped, or did it get hot and then stop? If it didn't get hot until after it stopped, it might be latch-up caused by not having the diodes. Did adding the heatsink make it run for a longer period of time before stopping?

in
Why didn't you put it in? It's not really optional. Put the bypass caps in too.

How much current does the motor draw? What voltage are you using to drive the motor?
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Thank you for you replay
I thought that the diods are optional so I didn't attache them, I attached the bypass capacitors.
For the motors each draws 1.5 Amp , with 24v so I don't think they exceed the rating of the chip.
I think the chip get hot after it stops. so I will attache the diod and see what happen.
Thank you again.
Ahmed
Anthony Fremont wrote:

If
by
longer
the
put
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The diodes are NOT optional on the L298.
DLC
: Thank you for you replay
: I thought that the diods are optional so I didn't attache them, I : attached the bypass capacitors.
: For the motors each draws 1.5 Amp , with 24v so I don't think they : exceed the rating of the chip.
: I think the chip get hot after it stops. so I will attache the diod and : see what happen.
: Thank you again.
: Ahmed
: Anthony Fremont wrote: : > "ahosyney" wrote : > > Hi all : > > : > > We are using a L298 IC to control DC motors from a uControler. The : > > problem is that it suddnly stops after a short run and became very : > hot. : > : > Did it get hot _after_ it stopped, or did it get hot and then stop? : If : > it didn't get hot until after it stopped, it might be latch-up caused : by : > not having the diodes. Did adding the heatsink make it run for a : longer : > period of time before stopping? : > : > > We attached a heat sink to cool down the chip but it didn't solve : the : > > problem. In the datasheet there is a Diode bridge that we didn't : put : > in : > : > Why didn't you put it in? It's not really optional. Put the bypass : > caps in too. : > : > > the circuit. Any one have any idea about the problem. : > : > How much current does the motor draw? What voltage are you using to : > drive the motor?
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ahosyney wrote:

The diode bridge is used to control the flyback voltage from the motor. If you don't put it in, you are going to destroy your output stage.

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