SLVSIR8 June   2026 TPS61383-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 VCC Power Supply and UVLO Logic
        1. 6.3.1.1 Internal VCC
      2. 6.3.2 Enable or Shutdown
      3. 6.3.3 Spread Spectrum
      4. 6.3.4 STATUS Pin
        1. 6.3.4.1 Status Indicatior IO (STATUS Pin)
        2. 6.3.4.2 Configured as External PMOS Driver
      5. 6.3.5 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Charger Feature Description
        1. 6.4.1.1 Charger Enable
        2. 6.4.1.2 LDO Charger and Buck Charger Description
          1. 6.4.1.2.1 Buck Charger
          2. 6.4.1.2.2 LDO Charger
        3. 6.4.1.3 NiMH Battery Charging Profile
          1. 6.4.1.3.1 Manual Charge Mode
        4. 6.4.1.4 Lithium Battery Charging Profile
        5. 6.4.1.5 Super Capacitor Charging Profile
        6. 6.4.1.6 Battery Cold, Hot Temperature (TS Pin)
        7. 6.4.1.7 Charger Protection and Fault Condition Indication
      2. 6.4.2 Boost Feature Description
        1. 6.4.2.1 Enable and Start-Up
          1. 6.4.2.1.1 Automatic Transition into Boost Mode
          2. 6.4.2.1.2 Manual Transition into Boost Mode
        2. 6.4.2.2 Down Mode
        3. 6.4.2.3 Output Short-to-Ground Protection
        4. 6.4.2.4 Boost Control Loop
        5. 6.4.2.5 Current Limit Operation
        6. 6.4.2.6 Functional Modes at Light Load
          1. 6.4.2.6.1 Auto PFM Mode
          2. 6.4.2.6.2 Forced PWM Mode
        7. 6.4.2.7 Duty Cycle Limitation
        8. 6.4.2.8 BUB Voltage Loop
      3. 6.4.3 Battery State-of-Health (SOH) Detection Mode Description
        1. 6.4.3.1 SOH Mode Operation
        2. 6.4.3.2 Multi-Signal Output in AVI Pin
        3. 6.4.3.3 Calculate Resistance of Super Capacitor
        4. 6.4.3.4 Calculate Capacitance of Super Capacitor
    5. 6.5 Programming I2C Serial Interface
      1. 6.5.1 Data Validity
      2. 6.5.2 START and STOP Conditions
      3. 6.5.3 Byte Format
      4. 6.5.4 Acknowledge (ACK) and Not Acknowledge (NACK)
      5. 6.5.5 Target Address and Data Direction Bit
      6. 6.5.6 Single Read and Write
      7. 6.5.7 Multi-Read and Multi-Write
  8. 7 Register Maps
    1. 7.1  Register 00H: CHIP_ID
    2. 7.2  Register 01H: BOOST_SET1
    3. 7.3  Register 02H: BOOST_SET2
    4. 7.4  Register 03H: BOOST_SET3
    5. 7.5  Register 04H: CHGR_SET1
    6. 7.6  Register 05H: CHGR_SET2
    7. 7.7  Register 06H: CHGR_SET3
    8. 7.8  Register 07H: CHGR_SET4
    9. 7.9  Register 08H: CHGR_STATUS
    10. 7.10 Register 09H: SOH_SET1
    11. 7.11 Register 0AH: SOH_SET2
    12. 7.12 Register 0BH: CONTROL_STATUS
    13. 7.13 Register 0CH: FAULT_CONDITION
    14. 7.14 Register 0DH: STATUS_PIN_SET
    15. 7.15 Register 0EH: SW_RST
  9. 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 Selecting the External MOSFET
        2. 8.2.2.2 Selecting the External Schottky
        3. 8.2.2.3 Inductor Selection
        4. 8.2.2.4 Capacitor in Super Capacitor Side
        5. 8.2.2.5 Selecting the Output Capacitor
        6. 8.2.2.6 Loop Stability and Compensation Design
          1. 8.2.2.6.1 Small Signal Analysis
          2. 8.2.2.6.2 Loop Compensation Design
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.4.2.8 BUB Voltage Loop

The TPS61383-Q1 applies BUB voltage loop to protect backup battery with high internal impedance, like batteries at low battery, cold temperature, or the end of life. This function allows the battery to output the maximum power and maintain the voltage over boost UVLO threshold when the battery has high internal resistance and that limits the output enough power for the output. This function is enabled by I2C BST_VINLOOP_EN bits and the input target voltage is programmed by BST_VINLOOP bits.

When the BUB voltage is higher than input target voltage, the BUB voltage loop is not activated. When the BUB voltage is lower than input target voltage, the BUB voltage loop takes over the controlling loop and try decreasing the inductor current to maintain the input voltage. So by allowing the VOUT to drop below VOUT_TARGET, TPS61383-Q1 turns to control the input voltage by which the battery matches the output impedance with internal impedance and output the maximum power.