JAJSLJ7A May   2021  – August 2021 TPS6521855

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     4
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Wake-Up and Power-Up and Power-Down Sequencing
        1. 7.3.1.1  Power-Up Sequencing
        2. 7.3.1.2  Power-Down Sequencing
        3. 7.3.1.3  Strobe 1 and Strobe 2
        4. 7.3.1.4  Supply Voltage Supervisor and Power-Good (PGOOD)
        5. 7.3.1.5  Internal LDO (INT_LDO)
        6. 7.3.1.6  Current Limited Load Switches
          1. 7.3.1.6.1 Load Switch 1 (LS1)
          2. 7.3.1.6.2 Load Switch 2 (LS2)
          3. 7.3.1.6.3 Load Switch 3 (LS3)
        7. 7.3.1.7  LDO1
        8. 7.3.1.8  UVLO
        9. 7.3.1.9  Power-Fail Comparator
        10. 7.3.1.10 DCDC3 and DCDC4 Power-Up Default Selection
        11. 7.3.1.11 I/O Configuration
          1. 7.3.1.11.1 Using GPIO3 as Reset Signal to DCDC1 and DCDC2
        12. 7.3.1.12 Push Button Input (PB)
          1. 7.3.1.12.1 Signaling PB-Low Event on the nWAKEUP Pin
          2. 7.3.1.12.2 Push Button Reset
        13. 7.3.1.13 AC_DET Input (AC_DET)
        14. 7.3.1.14 Interrupt Pin (INT)
        15. 7.3.1.15 I2C Bus Operation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Modes of Operation
      2. 7.4.2 OFF
      3. 7.4.3 ACTIVE
      4. 7.4.4 SUSPEND
      5. 7.4.5 RESET
    5. 7.5 Register Maps
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Applications Without Backup Battery
      2. 8.1.2 Applications Without Battery Backup Supplies
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Output Filter Design
        2. 8.2.2.2 Inductor Selection for Buck Converters
        3. 8.2.2.3 Output Capacitor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 サポート・リソース
    4. 11.4 Trademarks
    5. 11.5 静電気放電に関する注意事項
    6. 11.6 用語集
  12. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Package Option Addendum
      1. 12.1.1 Packaging Information
      2. 12.1.2 Tape and Reel Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

8.2.2.3 Output Capacitor Selection

The hysteretic PWM control scheme of the TPS6521855 switching converters allows the use of tiny ceramic capacitors. Ceramic capacitors with low ESR values have the lowest output voltage ripple and are recommended. The output capacitor requires either an X7R or X5R dielectric.

At light load currents the converter operates in power save mode, and the output voltage ripple is dependent on the output capacitor value and the PFM peak inductor current. Higher output capacitor values minimize the voltage ripple in PFM Mode and tighten DC output accuracy in PFM mode.

The two battery backup converters (DCDC5 and DCDC6) always operate in PFM mode. For these converters, a capacitor of at least 20 µF is recommended on the output to help minimize voltage ripple.

The buck-boost converter requires additional output capacitance to help maintain converter stability during high load conditions. At least 40 µF of output capacitance is recommended and an additional 100-nF capacitor can be added to further filter output ripple at higher frequencies.

Table 8-2 lists the recommended capacitors.

Table 8-3 List of Recommended Capacitors
PART NUMBER VALUE SIZE (mm) [L × W × H] MANUFACTURER
CAPACITORS FOR VOLTAGES UP TO 5.5 V(1)
GRM188R60J105K 1 µF 1608 / 0603 (1.6 × 0.8 × 0.8) Murata
GRM21BR60J475K 4.7 µF 2012 / 0805 (2.0 × 1.25 × 1.25) Murata
GRM31MR60J106K 10 µF 3216 / 1206 (3.2 × 1.6 × 1.6) Murata
GRM31CR60J226K 22 µF 3216 / 1206 (3.2 × 1.6 × 1.6) Murata
CAPACITORS FOR VOLTAGES UP TO 3.3 V(1)
GRM21BR60J106K 10 µF 2012 / 0805 (2.0 × 1.25 × 1.25) Murata
GRM31CR60J476M 47 µF 3216 / 1206 (3.2 × 1.6 × 1.6) Murata
(1) The DC bias effect of ceramic capacitors must be considered when selecting a capacitor.