DRV8262 Single Bridge vs Parallel Configuration for TEC Control

Hi Luis,

Thank you for your post.

Luis Contreras-Vidal said:

I'm using the DRV8262 to control a TEC with PWM. Do the H-bridges need to be paralleled even for single-bridge operation, or is paralleling only necessary when increasing the current limit?

The DRV8262 supports four MODES of full-bridge connections depending on MODE0 and MODE1 pin inputs at device power up or wake up from sleep. See below table from the datasheet. I could not confirm these MODE pins status from your schematic. MODE2 is floating, this is clear and it means PWM mode of bridge control. MODE1 seems like a control signal. If MODE1 = 1 at device power up or wake up it will function in Single H-bridge mode. In this mode, all OUT1 pins and all OUT2 pins must be externally tied together, both IPROPI pins and both VREF must be tied together as well. See second snippet. In the schematic IPROPI are tied together and VREF are as well. However, the missing connections are from the second bridge output. OUT1 and OUT3 are OUT1 as well as OUT2 and OUT4 are OUT2 in the Single H-bridge mode. 

If you'd like to use only one full-bridge and leave the other unconnected then MODE1 must be 0 to configure the device in dual H-bridge mode. The second bridge will be unused based on your schematic. You'll have to use IPROPI1 and VREF1 only - separated. See below pin out for dual H-bridge mode.

Luis Contreras-Vidal said:

I'm using a 12711-5P31-15CQ TEC rated to up to 15 amps

This may require single-H bridge parallel configuration along with the DRV8262 in DDV package - with external heatsink. The DDW package with thermal pad in the bottom of the IC can support to about 4.4 A continuous current with a 48 V supply and fPWM = 20 kHz. For higher PWM frequency and different VM voltages use the equations in section 7.1.1.3 Power Loss Calculations - Single H-bridge of the datasheet. Thank you.

Regards, Murugavel