JAJSGQ2F August   2013  – March 2019

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      充電器の効率
  4. 4 改訂履歴
  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 Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Maximum Power Point Tracking
      2. 7.3.2 Battery Undervoltage Protection
      3. 7.3.3 Battery Overvoltage Protection
      4. 7.3.4 Battery Voltage in Operating Range (VBAT_OK Output)
      5. 7.3.5 Push-Pull Multiplexer Drivers
      6. 7.3.6 Nano-Power Management and Efficiency
    4. 7.4 Device Functional Modes
      1. 7.4.1 Main Boost Charger Disabled (Ship Mode) - (VSTOR > VSTOR_CHGEN and EN = HIGH)
      2. 7.4.2 Cold-Start Operation (VSTOR < VSTOR_CHGEN, VIN_DC > VIN(CS) and PIN > PIN(CS))
      3. 7.4.3 Main Boost Charger Enabled (VSTOR > VSTOR_CHGEN, VIN_DC > VIN(DC) and EN = LOW )
      4. 7.4.4 Thermal Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Energy Harvester Selection
      2. 8.1.2 Storage Element Selection
      3. 8.1.3 Inductor Selection
      4. 8.1.4 Capacitor Selection
        1. 8.1.4.1 VREF_SAMP Capacitance
        2. 8.1.4.2 VIN_DC Capacitance
        3. 8.1.4.3 VSTOR Capacitance
        4. 8.1.4.4 Additional Capacitance on VSTOR or VBAT_SEC
    2. 8.2 Typical Applications
      1. 8.2.1 Solar Application Circuit
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Performance Plots
      2. 8.2.2 TEG Application Circuit
      3. 8.2.3 Design Requirements
        1. 8.2.3.1 Detailed Design Procedure
        2. 8.2.3.2 Application Performance Plots
      4. 8.2.4 Piezoelectric Application Circuit
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
        3. 8.2.4.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 デベロッパー・ネットワークの製品に関する免責事項
      2. 11.1.2 Zipファイル
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12メカニカル、パッケージ、および注文情報

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

8.1.2 Storage Element Selection

In order for the charge management circuitry to protect the storage element from over-charging or discharging, the storage element must be connected to VBAT pin and the system load tied to the VSTOR pin. Many types of elements can be used, such as capacitors, super capacitors or various battery chemistries. A storage element with 100uF equivalent capacitance is required to filter the pulse currents of the PFM switching charger. The equivalent capacitance of a battery can be computed as computed as:

Equation 7. bq25505 Eq07_CEQ_slusbj3.gif

In order for the storage element to be able to charge VSTOR capacitor (CSTOR) within the tVB_HOT_PLUG (50 ms typical) window at hot-plug; therefore preventing the IC from entering cold start, the time constant created by the storage element's series resistance (plus the resistance of the internal PFET switch) and equivalent capacitance must be less than tVB_HOT_PLUG . For example, a battery's resistance can be computed as:

Equation 8. RBAT = VBAT / IBAT(CONTINUOUS) from the battery specifications.

The storage element must be sized large enough to provide all of the system load during periods when the harvester is no longer providing power. The harvester is expected to provide at least enough power to fully charge the storage element while the system is in low power or sleep mode. Assuming no load on VSTOR (that is, the system is in low power or sleep mode), the following equation estimates charge time from voltage VBAT1 to VBAT2 for given input power is:

Equation 9. PIN x ηEST X tCHRG = 1/2 X CEQ X (VBAT22 - VBAT12)

Refer to SLUC463 for a design example that sizes the storage element.

Note that if there are large load transients or the storage element has significant impedance then it may be necessary to increase the CSTOR capacitor from the 4.7uF minimum or add additional capacitance to VBAT in order to prevent a droop in the VSTOR voltage. See Capacitor Selection for guidance on sizing capacitors.