ZHCS834G June   2011  – March 2020 TPS7A63-Q1 , TPS7A6401-Q1

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      固定输出电压选项
      2.      可调输出电压选项
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1  Power Up, Reset Delay, and Reset Output
      2. 7.3.2  Adjustable Output Voltage
      3. 7.3.3  Chip Enable
      4. 7.3.4  Charge Pump Operation
      5. 7.3.5  Low-Power Mode
      6. 7.3.6  Undervoltage Shutdown
      7. 7.3.7  Low-Voltage Tracking
      8. 7.3.8  Integrated Fault Protection
      9. 7.3.9  Thermal Shutdown
      10. 7.3.10 Integrated Window Watchdog
        1. 7.3.10.1 Programmable-Window Watchdog
        2. 7.3.10.2 Watchdog Enable
        3. 7.3.10.3 Watchdog Service Signal
        4. 7.3.10.4 Watchdog Fault Outputs
        5. 7.3.10.5 Watchdog Initialization
        6. 7.3.10.6 Watchdog Operation
        7. 7.3.10.7 Watchdog Fault Conditions
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation With VIN Lower Than 4 V
      2. 7.4.2 Operation With VIN Larger Than 4 V
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Example
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application Using the TPS7A6333-Q1 or TPS7A6350-Q1
        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 Using the TPS7A6401-Q1
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Power Dissipation and Thermal Considerations
        1. 10.1.1.1 Example
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 相关链接
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 Glossary
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.3.1 Power Up, Reset Delay, and Reset Output

During power up, the regulator incorporates a protection scheme to limit the current through the pass element and output capacitor. When the input voltage exceeds a certain threshold (VIN(POWERUP)) level, the output voltage begins to ramp up as shown in Figure 16.

When starting up, and also when the output recovers from a negative voltage spike due to a load step or a dip in the input voltage for a specified duration, the device implements reset delay to indicate that output voltage is stable and in regulation.

When the output voltage reaches the power-on-reset threshold (VTH(POR)) level, that is, 93% of regulated output voltage (3.3 V or 5 V, or a programmed value), a constant output current charges an external capacitor (CDLY) to an internal threshold (VTH(RDELAY)) voltage level. Then, nRST asserts high and CDLY discharges through an internal load. This allows CDLY to charge from approximately 0 V during the next power cycle.

Program the reset delay time by connecting an external capacitor (CDLY ,100 pF to 100 nF) to the RDELAY pin. Equation 1 gives the delay time:

Equation 1. TPS7A63-Q1 TPS7A6401-Q1 eq_tpor_lvsab1.gif

where

  • tPOR = reset delay time in seconds
  • CDLY = reset delay capacitor value in farads
TPS7A63-Q1 TPS7A6401-Q1 x_power_up_lvsab1.gifFigure 16. Power Up and Conditions for Activation of Reset
TPS7A63-Q1 TPS7A6401-Q1 x_reset_lvsab1.gifFigure 17. Reset Delay and Deglitch Filter

As Figure 17 shows, if the regulated output voltage falls below 93% of the set level, nRST asserts low after a short de-glitch time of approximately 5.5 µs (typical). In case of negative transients in the input voltage (VIN), the reset signal asserts low only if the output (VOUT) drops and stays below the reset threshold level (VTH(POR)) for more than the deglitch time (tDEGLITCH), as Figure 17 and Figure 20 illustrate. While nRST is low, if the input voltage returns to the nominal operating voltage, the normal power-up sequence ensues. nRST asserts high only if the output voltage exceeds the reset threshold voltage (VTH(POR)) and the reset delay time (tPOR) has elapsed.