SLUSDM0K May   2020  – June 2024 TPS628501-Q1 , TPS628502-Q1 , TPS628503-Q1

PRODMIX  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. Parameter Measurement Information
    1. 7.1 Schematic
  9. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Precise Enable (EN)
      2. 8.3.2 COMP/FSET
      3. 8.3.3 MODE / SYNC
      4. 8.3.4 Spread Spectrum Clocking (SSC)
      5. 8.3.5 Undervoltage Lockout (UVLO)
      6. 8.3.6 Power-Good Output (PG)
      7. 8.3.7 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode Operation (PWM/PFM)
      3. 8.4.3 100% Duty-Cycle Operation
      4. 8.4.4 Current Limit and Short Circuit Protection
      5. 8.4.5 Foldback Current Limit and Short-Circuit Protection
      6. 8.4.6 Output Discharge
      7. 8.4.7 Input Overvoltage Protection
  10. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Programming the Output Voltage
      2. 9.1.2 External Component Selection
        1. 9.1.2.1 Inductor Selection
      3. 9.1.3 Capacitor Selection
        1. 9.1.3.1 Input Capacitor
        2. 9.1.3.2 Output Capacitor
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Fixed Output Voltage Versions
      2. 9.3.2 Synchronizing to an External Clock
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Layout Guidelines

A proper layout is critical for the operation of a switched mode power supply, even more at high switching frequencies. Therefore, the PCB layout of the TPS62850x-Q1 demands careful attention to ensure operation and to get the performance specified. A poor layout can lead to issues like poor regulation (both in Section 9.5.2 and load), stability and accuracy weaknesses, increased EMI radiation, and noise sensitivity.

See for the recommended layout of the TPS62850x-Q1, which is designed for common external ground connections. The input capacitor must be placed as close as possible between the VIN and GND pin.

Provide low inductive and resistive paths for loops with high di/dt. Therefore, paths conducting the switched load current must be as short and wide as possible. Provide low capacitive paths (with respect to all other nodes) for wires with high dv/dt. Therefore, the input and output capacitance must be placed as close as possible to the IC pins and parallel wiring over long distances and narrow traces must be avoided. Loops which conduct an alternating current must outline an area as small as possible, as this area is proportional to the energy radiated.

Sensitive nodes like FB must be connected with short wires and not nearby high dv/dt signals (for example, SW). As they carry information about the output voltage, they must be connected as close as possible to the actual output voltage (at the output capacitor). The FB resistors, R1 and R2, must be kept close to the IC and be connected directly to the pin and the system ground plane.

The package uses the pins for power dissipation. Thermal vias on the VIN and GND pins help to spread the heat into the pcb.

The recommended layout is implemented on the EVM and shown in the TPS628502EVM-092 Evaluation Module User's Guide.