SLVSGC5E January   2023  – October 2025 TPS62870 , TPS62871 , TPS62872 , TPS62873

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Options
  6. 5 Pin Configuration and Functions
  7. 6 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 I2C Interface Timing Characteristics
    7. 6.7 Timing Requirements
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed-Frequency DCS-Control Topology
      2. 7.3.2  Forced PWM and Power Save Modes
      3. 7.3.3  Precise Enable
      4. 7.3.4  Start-Up
      5. 7.3.5  Switching Frequency Selection
      6. 7.3.6  Output Voltage Setting
        1. 7.3.6.1 Output Voltage Range
        2. 7.3.6.2 Output Voltage Setpoint
        3. 7.3.6.3 Non-Default Output Voltage Setpoint
        4. 7.3.6.4 Dynamic Voltage Scaling
      7. 7.3.7  Compensation (COMP)
      8. 7.3.8  Mode Selection and Clock Synchronization (MODE/SYNC)
      9. 7.3.9  Spread Spectrum Clocking (SSC)
      10. 7.3.10 Output Discharge
      11. 7.3.11 Undervoltage Lockout (UVLO)
      12. 7.3.12 Overvoltage Lockout (OVLO)
      13. 7.3.13 Overcurrent Protection
        1. 7.3.13.1 Cycle-by-Cycle Current Limiting
        2. 7.3.13.2 Hiccup Mode
        3. 7.3.13.3 Current Limit Mode
      14. 7.3.14 Power Good (PG)
        1. 7.3.14.1 Standalone or Primary Device Behavior
        2. 7.3.14.2 Secondary Device Behavior
      15. 7.3.15 Remote Sense
      16. 7.3.16 Thermal Warning and Shutdown
      17. 7.3.17 Stacked Operation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power-On Reset
      2. 7.4.2 Undervoltage Lockout
      3. 7.4.3 Standby
      4. 7.4.4 On
    5. 7.5 Programming
      1. 7.5.1 Serial Interface Description
      2. 7.5.2 Standard, Fast, Fast Mode Plus Protocol
      3. 7.5.3 I2C Update Sequence
      4. 7.5.4 I2C Register Reset
  9. 8 Register Map
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Selecting the Inductor
        2. 9.2.2.2 Selecting the Input Capacitors
        3. 9.2.2.3 Selecting the Compensation Resistor
        4. 9.2.2.4 Selecting the Output Capacitors
        5. 9.2.2.5 Selecting the Compensation Capacitor, CC
        6. 9.2.2.6 Selecting the Compensation Capacitor, CC2
      3. 9.2.3 Application Curves
    3. 9.3 Best Design Practices
    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

7.3.5 Switching Frequency Selection

During device initialization, a resistor-to-digital converter in the device determines the state of the FSEL pin and sets the switching frequency of the DC/DC converter according to Table 7-2.

Table 7-2 Switching Frequency Options
FSEL PIN(1)SWITCHING FREQUENCY
Short to GND1.5MHz
6.2kΩ to GND2.25MHz
47kΩ to VIN2.5MHz
Short to VIN3MHz
(1) For a reliable voltage setting, make sure there is no stray current path connected to the FSEL pin and that the parasitic capacitance between the FSEL pin and GND is less than 100pF.

Figure 7-10 shows a simplified block diagram of the R2D converter used to detect the state of the FSEL pin (an identical circuit detects the state of the VSEL pin – see Section 7.3.6.2).


TPS62870 TPS62871 TPS62872 TPS62873 FSEL R2D Converter Functional Block Diagram

Figure 7-10 FSEL R2D Converter Functional Block Diagram

Detection of the state of the FSEL pin works as follows:

To detect the most significant bit (MSB), the circuit opens S1 and S2, and the input buffer detects if a high or a low level is connected to the FSEL pin.

To detect the least significant bit (LSB):

  • If the MSB was 0, the circuit closes S1. If the input buffer detects a high level, LSB = 1. If the circuit detects a low level, LSB = 0.
  • If the MSB was 1, the circuit closes S2. If the input buffer detects a low level, LSB = 0. If the circuit detects a high level, LSB = 1.