SLVSFU1C April   2023  – October 2024 TPS62874-Q1 , TPS62875-Q1 , TPS62876-Q1 , TPS62877-Q1

PRODMIX  

  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 - Q100
    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 Typical Characteristics
  8. 7 Parameter Measurement Information
  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  Transient Non-Synchronous Mode (optional)
      4. 8.3.4  Precise Enable
      5. 8.3.5  Start-Up
      6. 8.3.6  Switching Frequency Selection
      7. 8.3.7  Output Voltage Setting
        1. 8.3.7.1 Output Voltage Range
        2. 8.3.7.2 Output Voltage Setpoint
        3. 8.3.7.3 Non-Default Output Voltage Setpoint
        4. 8.3.7.4 Dynamic Voltage Scaling
        5. 8.3.7.5 Droop Compensation
      8. 8.3.8  Compensation (COMP)
      9. 8.3.9  Mode Selection / Clock Synchronization (MODE/SYNC)
      10. 8.3.10 Spread Spectrum Clocking (SSC)
      11. 8.3.11 Output Discharge
      12. 8.3.12 Undervoltage Lockout (UVLO)
      13. 8.3.13 Overvoltage Lockout (OVLO)
      14. 8.3.14 Overcurrent Protection
        1. 8.3.14.1 Cycle-by-Cycle Current Limiting
        2. 8.3.14.2 Hiccup Mode
        3. 8.3.14.3 Current-Limit Mode
      15. 8.3.15 Power Good (PG)
        1. 8.3.15.1 Standalone, Primary Device Behavior
        2. 8.3.15.2 Secondary Device Behavior
      16. 8.3.16 Remote Sense
      17. 8.3.17 Thermal Warning and Shutdown
      18. 8.3.18 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 HS-Mode Protocol
      4. 8.5.4 I2C Update Sequence
      5. 8.5.5 I2C Register Reset
      6. 8.5.6 Dynamic Voltage Scaling (DVS)
  10. 9 Device Registers
  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 Inductor Selection
        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 Typical Application Using Two TPS62876-Q1 in a Stacked Configuration
      1. 10.3.1 Design Requirements For Two Stacked Devices
      2. 10.3.2 Detailed Design Procedure
        1. 10.3.2.1 Selecting the Compensation Resistor
        2. 10.3.2.2 Selecting the Output Capacitors
        3. 10.3.2.3 Selecting the Compensation Capacitor CC
      3. 10.3.3 Application Curves for Two Stacked Devices
    4. 10.4 Typical Application Using Three TPS62876-Q1 in a Stacked Configuration
      1. 10.4.1 Design Requirements For Three Stacked Devices
      2. 10.4.2 Detailed Design Procedure
        1. 10.4.2.1 Selecting the Compensation Resistor
        2. 10.4.2.2 Selecting the Output Capacitors
        3. 10.4.2.3 Selecting the Compensation Capacitor CC
      3. 10.4.3 Application Curves for Three Stacked Devices
    5. 10.5 Best Design Practices
    6. 10.6 Power Supply Recommendations
    7. 10.7 Layout
      1. 10.7.1 Layout Guidelines
      2. 10.7.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    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

Package Options

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

8.3.4 Precise Enable

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

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


TPS62874-Q1 TPS62875-Q1 TPS62876-Q1 TPS62877-Q1 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 10.1).

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 SYNC_OUT pins. The device also pulls EN low if a fault such as thermal shutdown or overvoltage lockout occurs. In a stacked configuration 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 8.3.18).

In stand-alone (non-stacked) applications, you can disable the active pulldown of the EN pin if you set SINGLE = 1 in the CONTROL3 register. Fault conditions have no effect on the EN pin when SINGLE = 1. (Note that 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 and a low level disables the DC/DC converter in the device. (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 20µA (typical).

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