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TEC adjustable current driver

Nessim Ben Ammar
Intellectual 800 points

Other Parts Discussed in Thread: ADS1247, OPA569

Hello,

im not sure if i'm posting in the right forum, so please fell free to transfer it.

I'm looking to drive a Peltier  (up to 10 A) element with a regulated current.

Since the resistance value of Peltier elements is temperature dependent, applying a voltage results in a current peak that drops before settling...

The dream would be like a current source digitally selectable : kinda" set current to 3.5 Amps in + direction"

Or a IC Combination with minimal circuitry to provide such function.

Any idea what would be the best  way to do so ?

On the circuit are one Family 6 MSP430 with USB and ADS1247 /8 if needed

regards

Nessim

  • 0
    TI__Guru* 93105 points

    Hi Nessim,

    Evaluating your Peltier drive requirements with a current up to 10 amperes requires the use of one, or more, power operational amplifiers. I suspect from your description that you probably would prefer to stay with a single supply device. There are power operational amplifiers that will supply up to 10 amps output, but are not likely as well suited as others for this application. I would recommend taking a look at the OPA569 power operational amplifier. The data sheet can be viewed here:

    http://www.ti.com/product/opa569

    The OPA569 peak current is listed as 2.2 amperes which is about a quarter of what you need. The OPA569 has a unique feature in that several of them can be connected in parallel to increase the available output current. The method for paralleling the is shown in Figure 14 in the data sheet. Four, or 5, of them will get you close to, or over the 10 Amperes. Note they are in a small, SO-20 PowerPad package so they don't take up much space. You still have to be careful about proper thermal management when dealing with a high power application. The data sheet provides all the needed thermal information.

    OPA569 data sheet figures 20 and 21 show two thermal electric cooler (TEC) applications. Figure 21 is an asymmetrical bipolar power supply configuration and figure 20 is bridge-tied driver which can be used to force current in one direction, or the other. The latter is useful when the TEC is required to heat, or cool.

    The power operational amplifier could be configured as desired and driven by a DAC to provide the required current through the Peltier element.

    Regards, Thomas

    PA - Linear Applications Engineering