LM5109B: TEC Heating Cooling. Current flow inversion via H-bridge

F. Schmuki

Part Number: LM5109B
Other Parts Discussed in Thread: SN6501

We are looking for a gate driver for a thermoelectric cooling (TEC / Peltier).
By means of a power source we operate a Peltier.
Switching between heating and cooling is done by a bridge circuit.
We are looking for a half or full bridge driver that can be operated statically.
The boost capacity for the HighSide-FET should be recharged independently without the load being disconnected for a short time.

Are there such gate drivers, and what would be the keyword to limit the search.
Currently we are using the LM5109B from TI, but this IC also has to hang the load for a short time to reload the boost capacity, which in turn disturbs the control loop of the power source.

Attached the schematics of our current design.
Application:
TEC cooling / heating by power source
24V DC / 3A

I would be pleased about a feedback.

TEC_Driver_Schematic.pdf

over 3 years ago

0 Richard Herring over 3 years ago

TI__Mastermind 20950 points

Hello,

It sounds like the main issue is to address the floating high side driver bias and the limitations of the bootstrap diode method for generating the high side bias.

This bias approach is limited regarding long on times or DC operation of the high side driver and the need to recharge the boot capacitor periodically.

TI has small devices specifically targeted to generate a floating bias which is the SN6501 and SN6505 transformer drivers. Using one of these devices to generate the high side floating bias would resolve your concerns about the bootstrap bias method.

The SN6501 datasheet can be found here:

https://www.ti.com/lit/ds/symlink/sn6501.pdf?ts=1600356804435&ref_url=https%253A%252F%252Fwww.google.com%252F

Confirm if this addresses your question, or you can post additional questions on this thread.

Regards,