JAJSDB7B June   2017  – October 2021 TPS7A83A

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 概要 (続き)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics: General
    6. 7.6 Electrical Characteristics: TPS7A8300A
    7. 7.7 Electrical Characteristics: TPS7A8301A
    8. 7.8 Typical Characteristics: TPS7A8300A
    9. 7.9 Typical Characteristics: TPS7A8301A
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Voltage Regulation Features
        1. 8.3.1.1 DC Regulation
        2. 8.3.1.2 AC and Transient Response
      2. 8.3.2 System Start-Up Features
        1. 8.3.2.1 Programmable Soft-Start (NR/SS)
        2. 8.3.2.2 Internal Sequencing
          1. 8.3.2.2.1 Enable (EN)
          2. 8.3.2.2.2 Undervoltage Lockout (UVLO) Control
          3. 8.3.2.2.3 Active Discharge
        3. 8.3.2.3 Power-Good Output (PG)
      3. 8.3.3 Internal Protection Features
        1. 8.3.3.1 Foldback Current Limit (ICL)
        2. 8.3.3.2 Thermal Protection (Tsd)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Regulation
      2. 8.4.2 Disabled
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 External Component Selection
        1. 9.1.1.1 Adjustable Operation
        2. 9.1.1.2 ANY-OUT Programmable Output Voltage
        3. 9.1.1.3 ANY-OUT Operation
        4. 9.1.1.4 Increasing ANY-OUT Resolution for LILO Conditions
        5. 9.1.1.5 Recommended Capacitor Types
        6. 9.1.1.6 Input and Output Capacitor Requirements (CIN and COUT)
        7. 9.1.1.7 Feed-Forward Capacitor (CFF)
        8. 9.1.1.8 Noise-Reduction and Soft-Start Capacitor (CNR/SS)
      2. 9.1.2 Start Up
        1. 9.1.2.1 Soft-Start (NR/SS)
          1. 9.1.2.1.1 Inrush Current
        2. 9.1.2.2 Undervoltage Lockout (UVLO)
        3. 9.1.2.3 Power-Good (PG) Function
      3. 9.1.3 AC and Transient Performance
        1. 9.1.3.1 Power-Supply Rejection Ratio (PSRR)
        2. 9.1.3.2 Output Voltage Noise
        3. 9.1.3.3 Optimizing Noise and PSRR
          1. 9.1.3.3.1 Charge Pump Noise
        4. 9.1.3.4 Load Transient Response
      4. 9.1.4 DC Performance
        1. 9.1.4.1 Output Voltage Accuracy (VOUT)
        2. 9.1.4.2 Dropout Voltage (VDO)
          1. 9.1.4.2.1 Behavior When Transitioning From Dropout Into Regulation
      5. 9.1.5 Sequencing Requirements
      6. 9.1.6 Negatively Biased Output
      7. 9.1.7 Reverse Current
      8. 9.1.8 Power Dissipation (PD)
        1. 9.1.8.1 Estimating Junction Temperature
        2. 9.1.8.2 Recommended Area for Continuous Operation (RACO)
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 Evaluation Models
        2. 12.1.1.2 Spice Models
      2. 12.1.2 Device Nomenclature
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 サポート・リソース
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.3.2.2 Internal Sequencing

Controlling when a single power supply turns on can be difficult in a power distribution network (PDN) because of the high power levels inherent in a PDN, and the variations between the supplies. Figure 8-3 and Table 8-2 show how the LDO turn-on and turn-off times are set by the enable circuit (EN) and undervoltage lockout circuits (UVLO1,2(IN) and UVLOBIAS).

GUID-14CA0243-FD9B-4E9D-A8C1-FA48C505F730-low.gif Figure 8-3 Simplified Turn-On Control
Table 8-2 Internal Sequencing Functionality Table
INPUT VOLTAGE BIAS VOLTAGE ENABLE STATUS LDO STATUS ACTIVE DISCHARGE POWER GOOD
VIN ≥ VUVLO_1,2(IN) VBIAS ≥ VUVLO(BIAS) EN = 1 On Off PG = 1 when VOUT ≥ VIT(PG)
EN = 0 Off On PG = 0
VBIAS < VUVLO(BIAS) + VHYS(BIAS) EN = don't care Off On (1)
VIN < VUVLO_1,2(IN) – VHYS1,2(IN) BIAS = don't care Off
IN = don't care VBIAS ≥ VUVLO(BIAS) Off
(1) The active discharge remains on as long as VIN or VBIAS provide enough headroom for the discharge circuit to function.