TIDA-050017: High current bipolar TEC driver using synchronous buck

Part Number: TIDA-050017
Other Parts Discussed in Thread: LM73606, LM61480, TPS55288, LM5175

Hello, 

i am designing a TEC controller based on dc-dc converters, similarly to what is reported in TIDA-050017. I would like to ask for some info about the following points.

1) For this purpose I am trying to identify a 2-quadrant buck converter with the following (general) characteristics:

- type: buck/buck-boost/synchronous buck

- current capability > 4.5 A both in sourcing and sinking (2-quadrant operation)

- price < 3 USD

- output voltage range: 1 V to 12 V minimim

- external inductor/internal switches are preferred (converters) 

Are there some parts from TI which could be a match?

2) I was taking a look at TI products to see whether I could find a synchronous buck with sufficient current sinking capability, in order to be able to reverse the TEC current. The current needed during cooling is generally greater than the one needed for heating, but I was trying to identify a component with sufficient balancing between maximum sourcing and sinking current capability.

  2a) In this regard, the LM61480 and LM73606 are reported to have a -5.3 A and -5 A sink limit, respectively. Could these ICs be a match for the stated application?

  2b) Are there any parts like the TPS6307x, but capable of handling greater currents in sourcing and sinking? For example the TPS55288 could be a candidate, but no reverse current limits are specified on the datasheet.


3) Another solution I was investigating was to use a 4-quadrant converter like the LT8714 from AD in order to have bipolar regulation on a single output. Are similar solutions available from TI?

 

Thanks for your help and best regards,

DP

  • Hi DP,

    The converters that you've listed may not work since the negative current limit of the device may be as high as -3.2A for LM61480 (8A).

    The LM73606 may work since the typical negative current limit is -6A but I would budget for slightly higher negative current limit if possible.

    would suggest either using a buck-boost converter or even buck controller (perhaps the LM21495) to achieve the sinking capability that you desired in your application.

    Regards,

    Jimmy 

  • Dear Jimmy, 

    thank you for your answer. 

    The LM21495 you suggested does not seem to be an existing part no. 

    Furthermore, do you have any products to suggest with regards to point 4) ?

    Thanks!

    Best regards, 

    DP

  • Hi DP,

    Apologies that was a typo. I meant to say LM25149. This is one of TI's newer controllers that was recently released to market.

    Unfortunately I am not too familiar with the portfolio in your question posed in point 4. Perhaps you can take a look at the LM5175 as a starting point.

    I would suggest opening another E2E post for the buck boost team to help assign an appropriate apps engineer to assist you with component selection.

    Regards,

    Jimmy