Current limiting L298N

Thread Starter

mbek

Joined Oct 30, 2011
16
Hello,

Is it better to implement current limiting by using something like L6506 and thus modulating the INPUTs to L298 in some higher frequency PWM (found in application note), or connecting comparator to sensing resistor and using an AND gate to couple the comparator output together with my control logic's output pin which is supposed to enable/disable bridge on L298? I saw the second solution somewhere in the forums.
I'm using half of each bridge to drive phases of brushless motors.

Thanks
 

SgtWookie

Joined Jul 17, 2007
22,220
Why not just use the integrated L6506 solution? You'll reduce your parts count that way.

I'm not too fond of the L298; it's really old technology. You'll dissipate a good bit of power just in the bridge itself; and you'll have to get rid of all that heat somehow.
 

Thread Starter

mbek

Joined Oct 30, 2011
16
Well, power dissipation is really not that much of an issue because it will be implemented underwater with a metal housing used for cooling components :) But power consumption is an issue...

And yes, I hate the L298 :( I'm using just half of each bridge (need it for brushless control), and it really does heat up too much, therefore wasting precious Wh.

Is there an out-of-the-box half-H-bridge IC capable of at least 2A, or should I just take a couple of MOSFETs and make half bridges myself?
 

Thread Starter

mbek

Joined Oct 30, 2011
16
I have used the ST L6205 with great success--very rugged device--the powerso-20 package requires no discrete heatsink as it has a copper slug that solders to the circuit board--2.8A current rating--by paralleling sections, it can handle 5.6 amps per chip.

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00002345.pdf
Thanks, thanks to your link I managed to find _exactly_ what I was looking for - http://www.st.com/internet/analog/product/63243.jsp and http://www.st.com/internet/analog/product/63244.jsp
 
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