Multiple l298N motor drivers in parallel

Just a question of interest. Is it possible to connect lets say 5 l298n motor drivers in aprallel to make a 10A dual driver? 20A total?

That chip uses transistors and not FETs so no you can't put them in parallel and expect them to shair the current.

tawandapro: Just a question of interest. Is it possible to connect lets say 5 l298n motor drivers in aprallel to make a 10A dual driver? 20A total?

The SPEC sheet states ... "For higher currents, outputs can be paralleled. Take care to parallel channel 1 with channel 4 and channel 2 with channel 3."

A Paralleled L298 4 Amp H-Bridge used in Robocon 2007 ... http://www.ikalogic.com/4a-h-bridge-motor-driver-using-the-l298-ic-schematic/

Apparently, current sharing with the two H-Bridges inside the same L298 chip is "OK". But equally sharing 1/10 of the current over 10 H-Bridges in 5 chips is very tricky. If one H-Bridge turns ON before the other nine then it will see a huge load. If one H-Bridge turns OFF after the other nine then it will see a huge load.

If you do try paralleling 10 H-Bridges in five L298 chips then add a small Sense Resistor in each H-Bridge to help balance the current for that bridge.

Without proper "balancing" resistors you could get this ... Bridge #1 = 2.4 amps (needs the highest SENS R) Bridge #2 = 2.3 amps (needs 2nd highest SENS R) Bridge #3 = 2.2 amps (needs 3rd highest SENS R) Bridge #4 = 2.1 amps (needs 4th highest SENS R) Bridge #5 = 2.0 amps (needs typical SENS R is OK) Bridge #6 = 2.0 amps (needs typical SENS R is OK) Bridge #7 = 1.9 amps (needs 4th lowest SENS R) Bridge #8 = 1.8 amps (needs 3rd lowest SENS R) Bridge #9 = 1.7 amps (needs 2nd lowest SENS R) Bridge #10 = 1.6 amps (needs the lowest SENS R) due to different Saturation Voltages within each H-Bridge.

See how Bridges #1 - #4 are running ABOVE their max rated amps?

Actually, I would DE-RATE the H-Bridges to say 1.5 Amps each. 1.5 amps each x 10 H-Bridge = 15 amps max in this configuration, for longevity. Then adjust SENS R for each bridge to run at 1.5 amps. That way a slight unbalance does not put you over the 2 amp max rating I would very conservatively FUSE each bridge independently. Although when one fuse blows the other fuses will probably "cascade" blow too. This will waste fuses but save your H-Bridges.

Also, you PCB layout must be SYMMETRICAL to balance the load.

You see what kind of tangled web this becomes?

If you had lots of free time on your hands you could read the Voltage across each SENS R and then use PWM to balance the amps in each H-Bridge in near real-time.

Or you could simply use a 20Amp MOSFET H-Bridge and H-Bridge Driver Chip.

Apparently, current sharing with the two H-Bridges inside the same L298 chip is "OK".

There is no apparently about it. The reason you can share with devices on the same chip is that they run at the same temperature so they track each other preventing thermal runaway.

But equally sharing 1/10 of the current over 10 H-Bridges in 5 chips is very tricky.

For tricky read impossible. I have been involved in a few projects over the years trying to get transistors to share current an ultimately it is just not a reliable technique.

Just get a device rated at what you want.