TIDUC99 August   2022 TPSM82903

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
    4. 2.4 System Design Theory
      1. 2.4.1 Buck Converter Circuit Design Using TPSM82903
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Startup
      2. 3.3.2 Shutdown
      3. 3.3.3 Load Transient
      4. 3.3.4 Output Ripple
      5. 3.3.5 Efficiency
      6. 3.3.6 Thermal Performance
      7. 3.3.7 Output Voltage vs. Output Current
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 PCB Layout Recommendations
        1. 4.1.3.1 Layout Prints
      4. 4.1.4 Altium Project
      5. 4.1.5 Gerber Files
      6. 4.1.6 Assembly Drawings
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks

2.4.1 Buck Converter Circuit Design Using TPSM82903

The TPSM82903 is optimized to work within a range of external components. A 1-μH inductor has been integrated to reduce solution size. Output capacitor selection can influence circuit stability; the recommended value for the output capacitor is 22 µF. SeeTPSM82903 data sheet for more details.

GUID-20220725-SS0I-0CV3-X0MN-H0Z18DX6DQXN-low.gif Figure 2-2 Buck Converter Circuit Design Using TPSM82903

A small low equivalent series resistance (ESR) multilayer ceramic capacitor (MLCC) is recommended to obtain the best filtering. For this design, a 10-µF/25V multilayer ceramic chip capacitor from TDK (C2012X7S1E106K125AC) is used as an input capacitor. The capacitor is designed to withstand up to 25-V which is enough for the input voltage range that we want to cover in this design.

For the output capacitor, the voltage rating is much smaller than the input, only 6-V to 10-V capacitor rating is needed. A 22-µF/10V multilayer ceramic chip capacitor (GRM21BD71A226ME44K) from Murata Manufacturing is chosen. The input and the output capacitors are X7S and X7T respectively; both of these cover the full temperature range needed for this design.

The MODE/S-CONF requires an E96 Resistor Series, 1% Accuracy, Temperature Coefficient better or equal than ±200- ppm/°C. A small size CRCW040226K1FKED from Vishay is used in this design.