ZHCSC57E November   2013  – December 2017 TPS56520 , TPS56720 , TPS56920 , TPS56C20

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用范围
  3. 3 说明
    1.     Device Images
      1.      典型应用电路
  4. 4 修订历史记录
  5. 5 说明 （续）
  6. 6 List of Devices
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
    2.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Switching Characteristics
    8. 8.8 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 PWM Operation
      2. 9.3.2 PWM Frequency and Adaptive On-Time Control
      3. 9.3.3 VIN and Power VIN Terminals (VIN and PVIN)
      4. 9.3.4 Auto-Skip Eco-mode™ Control
      5. 9.3.5 Soft Start and Pre-Biased Soft Start
      6. 9.3.6 Power Good
      7. 9.3.7 Overcurrent Protection
      8. 9.3.8 UVLO Protection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operation at Light Loads
    5. 9.5 Programming
      1. 9.5.1 I2C Interface
      2. 9.5.2 I2C Protocol
      3. 9.5.3 I2C Chip Address Byte
    6. 9.6 Register Maps
      1. 9.6.1 I2C Register Address Byte
      2. 9.6.2 Output Voltage Registers
      3. 9.6.3 CheckSum Bit (VOUT Register Only)
      4. 9.6.4 Control Registers
      5. 9.6.5 Latchoff
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 TPS56520, TPS56720 and TPS56920, 5-A, 7-A, and 9-A Converter
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Output Voltage Resistors Selection
            1. 10.2.1.2.1.1 Output Filter Selection
          2. 10.2.1.2.2 Input Capacitor Selection
          3. 10.2.1.2.3 Bootstrap Capacitor Selection
          4. 10.2.1.2.4 VREG5 Capacitor Selection
      2. 10.2.2 TPS56520, TPS56720 and TPS56920 Application Performance Curves
      3. 10.2.3 TPS56C20 12-A Converter
        1. 10.2.3.1 Design Requirements
        2. 10.2.3.2 Design Procedure
        3. 10.2.3.3 TPS56C20 Application Performance Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13器件和文档支持
    1. 13.1 器件支持
      1. 13.1.1 开发支持
    2. 13.2 文档支持
      1. 13.2.1 相关文档
    3. 13.3 相关链接
    4. 13.4 商标
    5. 13.5 静电放电警告
    6. 13.6 Glossary
  14. 14机械、封装和可订购信息

封装选项

请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • PWP|20
散热焊盘机械数据 (封装 | 引脚)
订购信息

10.2.1.2.1.1 Output Filter Selection

The output filter used with the TPS56X20 is an LC circuit. This LC filter has double pole at:

Equation 4. TPS56C20 TPS56920 TPS56720 TPS56520 eq3_Fp_lvsb3.gif

At low frequencies, the overall loop gain is set by the output set-point resistor divider network and the internal gain of the TPS56X20. The low frequency phase is 180 degrees. At the output filter pole frequency, the gain rolls off at a –40 dB per decade rate and the phase drops rapidly. D-CAP2™ introduces a high frequency zero that reduces the gain roll off to –20 dB per decade and increases the phase to 90 degrees one decade above the zero frequency. The inductor and capacitor selected for the output filter must be selected so that the double pole of Equation 4 is located below the high frequency zero but close enough that the phase boost provided be the high frequency zero provides adequate phase margin for a stable circuit. To meet this requirement use the values recommended in Table 5.

Table 5. Recommended Component Values

Output Voltage (V) R5 (kΩ) R6 (kΩ) C8 (pF)(1) L1 (µH) C7 (µF)
1 14.7 22 DNP 1.0-2.2 44-100
1.1 18.2 22 DNP 1.0-2.2 44-100
1.2 22 22 DNP 1.0-2.2 44-100
1.5 33 22 DNP 1.0-2.2 44-100
1.8 44.2 22 DNP 1.0-2.2 44-100
(1) Optional

For higher output voltages additional phase boost can be achieved by adding a feed forward capacitor (C6) in parallel with R5.

The inductor peak-to-peak ripple current, peak current and RMS current are calculated using Equation 5, Equation 6 and Equation 7. The inductor saturation current rating must be greater than the calculated peak current and the RMS or heating current rating must be greater than the calculated RMS current. Use 500 kHz for fSW.

Use 500 kHz for fSW. Make sure the chosen inductor is rated for the peak current of Equation 6 and the RMS current of Equation 7.

Equation 5. TPS56C20 TPS56920 TPS56720 TPS56520 eq4_Ilpp_lvsbv4.gif
Equation 6. TPS56C20 TPS56920 TPS56720 TPS56520 eq5_Ilpeak_lvsbv4.gif
Equation 7. TPS56C20 TPS56920 TPS56720 TPS56520 eq6_Ilorms_lvsbv4.gif

The capacitor value and ESR determines the amount of output voltage ripple. The TPS56X20 is intended for use with ceramic or other low ESR capacitors. Recommended values range from 44µF to 100µF. Use Equation 8 to determine the required RMS current rating for the output capacitor.

Equation 8. TPS56C20 TPS56920 TPS56720 TPS56520 eq8_lvsaAG1.gif