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

8.3.3 Precise Enable

The Enable (EN) pin is bidirectional and has two functions:

  • As an input, EN enables and disables the DC/DC converter in the device.
  • As an output, EN provides a SYSTEM_READY signal to other devices in a stacked configuration.

TPS62870 TPS62871 TPS62872 TPS62873 Enable Functional Block Diagram

Figure 8-6 Enable Functional Block Diagram
Because there is an internal open-drain transistor connected to the EN pin, do not drive this pin directly from a low-impedance source. Instead, use a resistor to limit the current flowing into the EN pin (see Section 10).

When power is first applied to the VIN pin, the device pulls the EN pin low until it has loaded the default register settings from nonvolatile memory and read the state of the VSEL, FSEL, and SYNCOUT pins. The device also pulls EN low if a fault, such as thermal shutdown or overvoltage lockout, occurs. In stacked configurations, all devices share a common enable signal, which means that the DC/DC converters in the stack cannot start to switch until all devices in the stack have completed the initialization. Similarly, a fault in one or more devices in the stack disables all converters in the stack (see Section 8.3.17).

In standalone (nonstacked) applications, the user can disable the active pulldown of the EN pin if the user sets SINGLE = 1 in the CONTROL3 register. Fault conditions have no effect on the EN pin when SINGLE = 1 (the EN pin is always pulled down during device initialization). In stacked applications, make sure that SINGLE = 0.

When the internal SYSTEM_READY signal is low (that is, initialization is complete and there are no fault conditions), the internal open-drain transistor is high impedance and the EN pin functions like a standard input. A high level on the EN pin enables the DC/DC converter in the device. A low level disables the DC/DC converter (the I2C interface is enabled as soon as the device has completed the initialization and is not affected by the state of the internal ENABLE or SYSTEM_READY signals).

A low level on the EN pin forces the device into shutdown. During shutdown, the MOSFETs in the power stage are off, the internal control circuitry is disabled, and the device consumes only 20 µA (typical).

The rising threshold voltage of the EN pin is 1.0V and the falling threshold voltage is 0.9 V. The tolerance of the threshold voltages is ±30mV, which means that the user can use the EN pin to implement precise turn-on and turn-off behavior.

When power is applied to the VIN pin, the toggling of the EN pin does not reset the loaded default register settings.