ZHCSBC7E JULY   2013  – December 2019 LMZ31710

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      简化应用
  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 (PVIN = VIN = 12 V)
    7. 6.7 Typical Characteristics (PVIN = VIN = 5 V)
    8. 6.8 Typical Characteristics (PVIN = 3.3 V, VIN = 5 V)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  VIN and PVIN Input Voltage
      2. 7.3.2  3.3-V PVIN Operation
      3. 7.3.3  Adjusting the Output Voltage (0.6 V to 5.5 V)
      4. 7.3.4  Capacitor Recommendations For the LMZ31710 Power Supply
        1. 7.3.4.1 Capacitor Technologies
          1. 7.3.4.1.1 Electrolytic, Polymer-Electrolytic Capacitors
          2. 7.3.4.1.2 Ceramic Capacitors
          3. 7.3.4.1.3 Tantalum, Polymer-Tantalum Capacitors
        2. 7.3.4.2 Input Capacitor
        3. 7.3.4.3 Output Capacitor
      5. 7.3.5  Transient Response
        1. 7.3.5.1 Transient Response Waveforms
      6. 7.3.6  Power Good (PWRGD)
      7. 7.3.7  Light Load Efficiency (LLE)
      8. 7.3.8  SYNC_OUT
      9. 7.3.9  Parallel Operation
      10. 7.3.10 Power-Up Characteristics
      11. 7.3.11 Pre-Biased Start-Up
      12. 7.3.12 Remote Sense
      13. 7.3.13 Thermal Shutdown
      14. 7.3.14 Output On/Off Inhibit (INH)
      15. 7.3.15 Slow Start (SS/TR)
      16. 7.3.16 Overcurrent Protection
      17. 7.3.17 Synchronization (CLK)
      18. 7.3.18 Sequencing (SS/TR)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Programmable Undervoltage Lockout (UVLO)
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Setting The Output Voltage
        3. 8.2.2.3 Setting the Switching Frequency
        4. 8.2.2.4 Input Capacitance
        5. 8.2.2.5 Output Capacitance
    3. 8.3 Additional Application Schematics
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Considerations
    2. 10.2 Layout Examples
      1. 10.2.1 EMI
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 开发支持
        1. 11.1.1.1 使用 WEBENCH® 工具创建定制设计
      2. 11.1.2 第三方产品免责声明
    2. 11.2 文档支持
      1. 11.2.1 相关文档
    3. 11.3 接收文档更新通知
    4. 11.4 支持资源
    5. 11.5 商标
    6. 11.6 静电放电警告
    7. 11.7 Glossary
  12. 12机械、封装和可订购信息
    1. 12.1 Tape and Reel Information

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

7.4.1 Programmable Undervoltage Lockout (UVLO)

The LMZ31710 implements internal UVLO circuitry on the VIN pin. The device is disabled when the VIN pin voltage falls below the internal VIN UVLO threshold. The internal VIN UVLO rising threshold is 4.5 V(max) with a typical hysteresis of 150 mV.

If an application requires either a higher UVLO threshold on the VIN pin or a higher UVLO threshold for a combined VIN and PVIN, then the UVLO pin can be configured as shown in Figure 39 or Figure 40. Table 8 lists standard values for RUVLO1 and RUVLO2 to adjust the VIN UVLO voltage up.

LMZ31710 slvsAW7_VinUVLO.gifFigure 39. Adjustable VIN UVLO
LMZ31710 slvsAW7_VinPVinUVLO.gifFigure 40. Adjustable VIN And Pvin Undervoltage Lockout

Table 8. Standard Resistor Values For Adjusting VIN UVLO

VIN UVLO (V) 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
RUVLO1 (kΩ) 68.1 68.1 68.1 68.1 68.1 68.1 68.1 68.1 68.1 68.1 68.1
RUVLO2 (kΩ) 21.5 18.7 16.9 15.4 14.0 13.0 12.1 11.3 10.5 9.76 9.31
Hysteresis (mV) 400 415 430 450 465 480 500 515 530 550 565

For a split rail application, if a secondary UVLO on PVIN is required, VIN must be ≥ 4.5 V. Figure 41 shows the PVIN UVLO configuration. Use Table 9 to select RUVLO1 and RUVLO2 for PVIN. If PVIN UVLO is set for less than 3.5 V, a 5.1-V zener diode must be added to clamp the voltage on the UVLO pin below 6 V.

LMZ31710 slvsAW7_PVinUVLO.gifFigure 41. Adjustable PVIN Undervoltage Lockout, (VIN ≥ 4.5 V)

Table 9. Standard Resistor Values For Adjusting Pvin UVLO, (VIN ≥ 4.5 V)

PVIN UVLO (V) 2.9 3.0 3.5 4.0 4.5
RUVLO1 (kΩ) 68.1 68.1 68.1 68.1 68.1 For higher PVIN UVLO voltages, see Table 8 for resistor values
RUVLO2 (kΩ) 47.5 44.2 34.8 28.7 24.3
Hysteresis (mV) 330 335 350 365 385