SNVAA70 june   2023 LM5176 , LM5176-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Principle of the TEC
    2. 1.2 Design Specification and Key Challenge
  5. 2Tec Driver Design Using Buck-Boost Controller
    1. 2.1 System Description
    2. 2.2 Block Diagram of TEC Design With LM5176
    3. 2.3 Output Voltage Control of LM5176
  6. 3Test Result
    1. 3.1 TEC Current Versus Output Voltage
    2. 3.2 Current Ripple Measurement Through TEC Element
    3. 3.3 Start-Up
    4. 3.4 Efficiency
  7. 4Summary
  8. 5References

2.1 System Description

Due to the direction change in this application, the power supply needs to have the capacity to sink and source current. The buck-boost regulator is a good choice in this application. Most buck-boost modules and converters are limited in sink current; therefore, the buck-boost controller is selected in this note. LM5176 is a wide-input voltage four-switch buck-boost controller device with integrated drivers for N-channel MOSFETs. LM5176 can automatically transfer between the buck and boost mode. When Vin equals Vout, the device also provides a low ripple output voltage.

In this design, the LM5176 is supplied by a regulated voltage rail of 15 V. The TEC is connected between the Vin and Vout pin of the LM5176. The output voltage can be varied from 5 V to 25 V by adjusting the Vctrl in the microcontroller. Since Vin is fixed, the voltage applied on the TEC can be changed from -10 V to 10 V, which can regulate the current of TEC.