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

Adjustable Operation

The TPS7A84 can be used either with the internal ANY-OUT network or by using external resistors. Using the ANY-OUT network allows the TPS7A84 to be programmed from 0.8 V to 3.95 V. To extend this output voltage range to 5.0 V, external resistors must be used. This configuration is referred to as the adjustable configuration of the TPS7A84 throughout this document. Regardless whether the internal resistor network or whether external resistors are used, the output voltage is set by two resistors, as shown in Figure 8-4. Using the internal resistor ensures a 1% accuracy and minimizes the number of external components.

GUID-0BDC73CA-9010-440B-8ED9-FC55EEDD0730-low.gifFigure 8-4 Adjustable Operation

R1 and R2 can be calculated for any output voltage range using Equation 8. This resistive network must provide a current equal to or greater than 5 μA for dc accuracy. Using an R1 of 12.1 kΩ is recommended to optimize the noise and PSRR.

Equation 8. VOUT = VNR/SS × (1 + R1 / R2)

Table 8-5 shows the resistor combinations required to achieve several common rails using standard 1%-tolerance resistors.

Table 8-5 Recommended Feedback-Resistor Values(1)
TARGETED OUTPUT VOLTAGE
(V)
FEEDBACK RESISTOR VALUESCALCULATED OUTPUT VOLTAGE
(V)
R1 (kΩ)R2 (kΩ)
0.912.41000.899
0.9512.466.50.949
1.0012.449.90.999
1.1012.433.21.099
1.2012.424.91.198
1.5012.414.31.494
1.8012.4101.798
1.9012.18.871.89
2.5012.45.92.48
2.8512.14.752.838
3.0012.14.422.990
3.3011.83.743.324
3.6012.13.483.582
4.511.82.554.502
5.0012.42.374.985
R1 is connected from OUT to FB; R2 is connected from FB to GND.