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ADN8831 : Would it be possible to drive a 3 stages TEC up to 8.8V ?

Question asked by ARC on Mar 14, 2016
Latest reply on Nov 24, 2016 by jingyy610

Dear all,

 

First, I would like to apologize if I am not in the right section. I think this is the most appropriate one to talk about a Thermoelectric cooler (TEC) controller.

 

So, I worked with the eval board of the ADN8831 TEC controller which gave me good results. But I would like to make a "module" with the AD8831. What I call module is a very small PCB with 16-20pins that I could plug in my PCB like an IC. This module is basically a TEC controller with all the external components.

 

My worry is that some of the TEC I have to control have 3 stages and then need a voltage up to 8.8V.

 

According to the ADN8831 datasheet, the Vdd cannot exceed 5.5V. Since the MOSFET are not included in the IC, I thought I can use 2 power supply (or one with and LDO on the module in order to have 2 different voltages: one for the power part and another for the logic). But I guess it would not work because the pins CS, LFB and maybe SW and SFB will have a voltage higher than Vdd which is not acceptable. As well, I need to find P-channel MOSFET which can be blocked with a Vgs voltage of 8.8V - Vdd... it can also be a problem.

 

A solution would be to translate voltages from Vdd to 8.8V (or 10V) in order to drive P-channel MOSFET and put some voltage dividers for the pins CS and LFB (and maybe more adaptations... I did not make a exhaustive list yet) but it might take too much room on my module.

 

If anyone has experience in this field, can (s)he tell me if my previous statements are right or it is much easier to achieve what I would like to do? As well, if anyone knows a similar IC which can control a TEC up to 8.8V, it would be nice.

 

Sorry for the long post.

 

Best regards,

 

Christian

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