SLUUBJ1B february   2017  – july 2023 TPS2373

 

  1.   1
  2.   TPS2373-4EVM-758 Evaluation Module
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Features
    2. 1.2 Applications
  5. 2Electrical Specifications
  6. 3Description
  7. 4Schematic
  8. 5General Configuration and Description
    1. 5.1 Physical Access
  9. 6TPS237xEVM-758 Performance Data
    1. 6.1 Startup
    2. 6.2 Transient Response
    3. 6.3 Efficiency
  10. 7EVM Assembly Drawings and Layout Guidelines
    1. 7.1 PCB Drawings
    2. 7.2 Layout Guidelines
    3. 7.3 EMI Containment
  11. 8Bill of Materials
  12. 9Revision History

3 Description

The TPS2373-4EVM-758 enables full evaluation of the TPS2373-4 device. Refer to the schematic shown in Figure 4-1 and Figure 4-2. Ethernet power is applied from J1 and is dropped to the FET bridge rectifier. At the output of the FET bridge is the EMI and EMC filter and transient protection for the TPS2373-4.

Input power can also be applied at J3 from a DC source when power at J1 is not present or when the DC/DC converter is being evaluated and not the PoE front end.

The TPS2373-4 (U1) PD controller is shown in Figure 4-1. R30 provides the detection signature while J7 and J10 allow user selection of the classification signature and desired power level. To the right of U1 is the switched side of the PD controller. The TPS2373-4 RTN pin provides inrush, current limited turn on, and charge of the bulk capacitor C28 and C62.

The DC/DC converter is a high-efficiency, active clamp-forward converter. The primary (Q16) switching MOSFET is driven from the U2 OUT pin and the secondary (Q13/Q15) synch switching MOSFET is in a self-driven configuration.

Output voltage feedback is provided with U3 and associated error amplifier (U4) circuitry. R55 provides a means for error injection to measure the frequency response of the converter. This feedback circuit drives the U2 FB pin which provides a voltage proportional to the output load current. As the output load current decreases, the FB pin voltage decreases.