ZHCSEI2B January   2016  – June 2021 TPS7A84

PRODUCTION DATA  

  1. 特性
  2. 应用
  3. 说明
  4. Revision History
  5. Pin Configurations and Functions
  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 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Low-Noise, High-PSRR Output
      2. 7.3.2  Integrated Resistance Network (ANY-OUT)
      3. 7.3.3  Bias Rail
      4. 7.3.4  Power-Good Function
      5. 7.3.5  Programmable Soft-Start
      6. 7.3.6  Internal Current Limit (ILIM)
      7. 7.3.7  Enable
      8. 7.3.8  Active Discharge Circuit
      9. 7.3.9  Undervoltage Lockout (UVLO)
      10. 7.3.10 Thermal Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation with 1.1 V ≤ VIN < 1.4 V
      2. 7.4.2 Operation with 1.4 V ≤ VIN ≤ 6.5 V
      3. 7.4.3 Shutdown
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Recommended Capacitor Types
      2. 8.1.2  Input and Output Capacitor Requirements (CIN and COUT)
      3. 8.1.3  Noise-Reduction and Soft-Start Capacitor (CNR/SS)
      4. 8.1.4  Feed-Forward Capacitor (CFF)
      5. 8.1.5  Soft-Start and In-Rush Current
      6. 8.1.6  Optimizing Noise and PSRR
      7. 8.1.7  Charge Pump Noise
      8. 8.1.8  ANY-OUT Programmable Output Voltage
      9. 8.1.9  ANY-OUT Operation
      10. 8.1.10 Increasing ANY-OUT Resolution for LILO Conditions
      11. 8.1.11 Current Sharing
      12. 8.1.12 Adjustable Operation
      13. 8.1.13 Sequencing Requirements
        1. 8.1.13.1 Sequencing with a Power-Good DC-DC Converter Pin
        2. 8.1.13.2 Sequencing with a Microcontroller (MCU)
      14. 8.1.14 Power-Good Operation
      15. 8.1.15 Undervoltage Lockout (UVLO) Operation
      16. 8.1.16 Dropout Voltage (VDO)
      17. 8.1.17 Behavior when Transitioning from Dropout into Regulation
      18. 8.1.18 Load Transient Response
      19. 8.1.19 Negatively-Biased Output
      20. 8.1.20 Reverse Current Protection
      21. 8.1.21 Power Dissipation (PD)
      22. 8.1.22 Estimating Junction Temperature
      23. 8.1.23 Recommended Area for Continuous Operation (RACO)
    2. 8.2 Typical Applications
      1. 8.2.1 Low-Input, Low-Output (LILO) Voltage Conditions
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Application for a 5.0-V Rail
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Board Layout
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Evaluation Modules
        2. 11.1.1.2 Spice Models
      2. 11.1.2 Device Nomenclature
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 接收文档更新通知
    4. 11.4 支持资源
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 术语表
  12. 12Mechanical, Packaging, and Orderable Information

Recommended Area for Continuous Operation (RACO)

The operational area of an LDO is limited by the dropout voltage, output current, junction temperature, and input voltage. The recommended area for continuous operation for a linear regulator can be separated into the following parts, and is shown in Figure 8-13:

  • Limited by dropout: Dropout voltage limits the minimum differential voltage between the input and the output (VIN – VOUT) at a given output current level.
  • Limited by rated output current: The rated output current limits the maximum recommended output current level. Exceeding this rating causes the device to fall out of specification.
  • Limited by thermals: The shape of the slope is given by Equation 11. The slope is nonlinear because the junction temperature of the LDO is controlled by the power dissipation across the LDO; therefore, when VIN – VOUT increases, the output current must decrease in order to ensure that the rated junction temperature of the device is not exceeded. Exceeding this rating can cause the device to fall out of specifications and reduces long-term reliability.
  • Limited by VIN range: The rated input voltage range governs both the minimum and maximum of VIN – VOUT.

GUID-20727FE9-8287-4FD5-AC63-E719CCFF8AE3-low.gifFigure 8-13 Continuous Operation Slope Region Description

Figure 8-14 to Figure 8-19 show the recommended area of operation curves for this device on a JEDEC-standard high-K board with a RθJA = 35.4°C/W, as given in the Section 6.5 table.

GUID-2EA74D51-D174-4CB6-8BE3-BF3C752F8FCF-low.gifFigure 8-14 Recommended Area for Continuous Operation for VOUT = 0.9 V With Bias
GUID-2FF199FB-3A08-4C31-9E71-4421B3593EF4-low.gifFigure 8-16 Recommended Area for Continuous Operation for VOUT = 1.8 V
GUID-58879EFB-4322-4B1A-9FB6-97B48CC96DA3-low.gifFigure 8-18 Recommended Area for Continuous Operation for VOUT = 3.3 V
GUID-D7BC309F-B0AE-4344-BD05-9BBAA209204C-low.gifFigure 8-15 Recommended Area for Continuous Operation for VOUT = 1.2 V With Bias
GUID-697958D6-40EC-4336-A0F4-66674A781AA7-low.gifFigure 8-17 Recommended Area for Continuous Operation for VOUT = 2.5 V
GUID-0279B301-43B4-4DBE-A17F-54FDE81D5FDA-low.gifFigure 8-19 Recommended Area for Continuous Operation for VOUT = 5.0 V