SLVSGC5B January   2023  – May 2024 TPS62870 , TPS62871 , TPS62872 , TPS62873

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Device Options
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings_Catalog
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Interface Timing Characteristics
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Fixed-Frequency DCS Control Topology
      2. 8.3.2  Forced PWM and Power Save Modes
      3. 8.3.3  Precise Enable
      4. 8.3.4  Start-Up
      5. 8.3.5  Switching Frequency Selection
      6. 8.3.6  Output Voltage Setting
        1. 8.3.6.1 Output Voltage Range
        2. 8.3.6.2 Output Voltage Setpoint
        3. 8.3.6.3 Non-Default Output Voltage Setpoint
        4. 8.3.6.4 Dynamic Voltage Scaling
      7. 8.3.7  Compensation (COMP)
      8. 8.3.8  Mode Selection and Clock Synchronization (MODE/SYNC)
      9. 8.3.9  Spread Spectrum Clocking (SSC)
      10. 8.3.10 Output Discharge
      11. 8.3.11 Undervoltage Lockout (UVLO)
      12. 8.3.12 Overvoltage Lockout (OVLO)
      13. 8.3.13 Overcurrent Protection
        1. 8.3.13.1 Cycle-by-Cycle Current Limiting
        2. 8.3.13.2 Hiccup Mode
        3. 8.3.13.3 Current Limit Mode
      14. 8.3.14 Power Good (PG)
        1. 8.3.14.1 Standalone or Primary Device Behavior
        2. 8.3.14.2 Secondary Device Behavior
      15. 8.3.15 Remote Sense
      16. 8.3.16 Thermal Warning and Shutdown
      17. 8.3.17 Stacked Operation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-On Reset
      2. 8.4.2 Undervoltage Lockout
      3. 8.4.3 Standby
      4. 8.4.4 On
    5. 8.5 Programming
      1. 8.5.1 Serial Interface Description
      2. 8.5.2 Standard, Fast, Fast Mode Plus Protocol
      3. 8.5.3 I2C Update Sequence
      4. 8.5.4 I2C Register Reset
  10. 9 Register Map
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Selecting the Inductor
        2. 10.2.2.2 Selecting the Input Capacitors
        3. 10.2.2.3 Selecting the Compensation Resistor
        4. 10.2.2.4 Selecting the Output Capacitors
        5. 10.2.2.5 Selecting the Compensation Capacitor, CC
        6. 10.2.2.6 Selecting the Compensation Capacitor, CC2
      3. 10.2.3 Application Curves
    3. 10.3 Best Design Practices
    4. 10.4 Power Supply Recommendations
    5. 10.5 Layout
      1. 10.5.1 Layout Guidelines
      2. 10.5.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

8.3.14.1 Standalone or Primary Device Behavior

The primary purpose of the PG pin is to indicate if the output voltage is in regulation, but it also indicates if the device is in thermal shutdown or disabled. Table 8-7 summarizes the behavior of the PG pin in a standalone or primary device.

Table 8-7 Power-Good Function Table
VINENVOUTSoft StartPGBLNKDVSTJPG
2V > VINXXXXXUndefined
VIT(UVLO) ≥ VIN ≥ 2VXXXXXLow
VIN > VIT(UVLO)LXXXXLow
HXActiveXXLow
VOUT > VT(PGOV)

or

< VT(PGUV) > VOUT

Inactive0Xlow
1

(and DVS is active)

TJ < TSDHi-Z
VT(PGOV) > VOUT > VT(PGUV)XTJ < TSDHi-Z
XXXTJ > TSDLow

Figure 8-12 shows a functional block diagram of the power-good function in a standalone or primary device. A window comparator monitors the output voltage, and the output of the comparator goes high if the output voltage is either less than 95% (typical) or greater than 105% (typical) of the nominal output voltage. The output of the window comparator is deglitched – the typical deglitch time is 40µs – and then used to drive the open-drain PG pin.


TPS62870 TPS62871 TPS62872 TPS62873 Power-Good Functional Block Diagram (Standalone or Primary Device)
Figure 8-12 Power-Good Functional Block Diagram (Standalone or Primary Device)

During DVS activity, when the DC/DC converter transitions from one output voltage setting to another, the output voltage can temporarily exceed the limits of the window comparator and pull the PG pin low. The device has a feature to disable this behavior. If PGBLNKDVS = 1 in the CONTROL3 register, the device ignores the output of the power-good window comparator while DVS is active.

Note that the PG pin is always low, regardless of the output of the window comparator, when:

  • The device is in thermal shutdown.
  • The device is disabled.
  • The device is in undervoltage lockout.
  • The device is in soft start.