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DRV8432: Looking for high power options for TEC (Peltier) driver

Part Number: DRV8432

Hello,

I'm upgrading a hand-made TEC driver and want to get some features/minituarization from purpose-built ICs. 

We're looking at 15V-24V and 6-10A.  24V / 15A would cover pretty much everything, and 15V/6A covers over half of the usecases.  

It appears the motor driver ICs are more suited for this. Is there a buck-boost / sepic / cuk controller or something that can accomplish a similar effect?  

It seems DRV8432, DRV8412, are my best options as they have external FETs and are thus more easily scalable in power.  All the others seem to have integrated FETs at around 10-12A max. 

Are there any with built-in PID?

Is there any other feature I'm overlooking? This is basically a buck-converter on one side of the bridge and a switch HI/LO on the other side.   Anything with independent controls of the H-Bridge should work. 

What do I really gain from these "specialized" driver ICs in my TEC application, that I won't get from just using, eg. , a pair of LM5106/LM5109.  Aside from the fault detection and EMI features, the actual power conversion features are just dead-time control and current sensing, as far as I could learn.  

Finally, are there any of these types of ICs that are in high-volume production, and at low risk of EOL / stock-issues / etc.?  

Thank you for your help. I've been reading up on these ICs today and have a lot of data to parse through. I appreciate any help I get. 

-Romeo

  • Romeo,

    The DRV8412/8432 are actually integrated FET devices.  For external FETs, you would need to consider something like the DRV8705-Q1 (single bridge) or DRV8714/18-Q1 (up to 8 1/2 bridges that are configurable).  

    These devices are very capable external FET drivers that would give you the scalability that you need.

    We have various links that you might find interesting:

    https://www.ti.com/lit/an/slua979a/slua979a.pdf

    https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/967858/faq-what-motor-drivers-should-be-considered-for-driving-thermoelectric-cooling-tec-elements-or-peltier-devices

    Regards,

    Ryan

  • Thank you Ryan.  Yes indeed I was looking at 8714 & 8701 for external FETs, not sure how I flubbed up the P/N.   8701/8714 were on my "External FETs" and 8432/8412 were internal FETs. 

    I did read your FAQ before posting -- terrific and helpful!

    Do you have any recommendations for buck converters that can act in such a place? We're more space than cost constrained, so some 2MHz+ switcher will probably be ideal.

    Of course, it would need to be capable of +/- generation or, more practically, fully-synchronous and capable of a forced-continuous / current-sinking mode.

    Not critical, but a nice clean method of breaking into it's control loop with our PID loop would be great.

    Is there something inherent to these "motor controllers" that are crucial to TEC drivers?  Why choose a DRVxxx over a standard gate driver?

    I've skimmed SLUA979A and will continue reading now.

    If it helps, I can chat via phone pretty much anytime 8-6 PM EST.

    Thanks again!!

  • Romeo,

    Versus a standard gate driver, motor drivers provide more protection features for short circuit, open load, etc.  Gate drivers are usually more basic building blocks that certainly can be used in your application.  

    Limitation on most of our motor drivers is switching frequency...DRV8412/32 is an exception.  Motors don't require switching frequencies of +1MHz, so that is definitely where a buck converter would be give you the benefit of smaller filter components.  

    I would suggest posting in the power management forum for a suggestion.  I have checked thru some app notes and don't see a design with external FETs that would provide the power you need.  

    Regards,

    Ryan