SLUSFO4 August   2024 BQ25758A

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Power-On-Reset
      2. 7.3.2 Device Power-Up From Battery Without Input Source
      3. 7.3.3 Device Power Up from Input Source
        1. 7.3.3.1 VAC Operating Window Programming (ACUV and ACOV)
        2. 7.3.3.2 MODE Pin Configuration
        3. 7.3.3.3 REGN Regulator (REGN LDO)
        4. 7.3.3.4 Switching Frequency and Synchronization (FSW_SYNC)
        5. 7.3.3.5 Device HIZ Mode
      4. 7.3.4 Power Management
        1. 7.3.4.1 Output Voltage Programming (VOUT_REG)
        2. 7.3.4.2 Output Current Programming (IOUT pin and IOUT_REG)
        3. 7.3.4.3 Dynamic Power Management: Input Voltage and Input Current Regulation
          1. 7.3.4.3.1 Input Current Regulation
            1. 7.3.4.3.1.1 IIN Pin
            2. 7.3.4.3.1.2 Multi-Level Current Limit (Overload Mode)
          2. 7.3.4.3.2 Input Voltage Regulation
        4. 7.3.4.4 Bypass Mode
      5. 7.3.5 Bidirectional Power Flow and Programmability
      6. 7.3.6 Integrated 16-Bit ADC for Monitoring
      7. 7.3.7 Status Outputs (PG, STAT and INT)
        1. 7.3.7.1 Power Good Indicator (PG)
        2. 7.3.7.2 Interrupt to Host (INT)
      8. 7.3.8 Protections
        1. 7.3.8.1 Voltage and Current Monitoring
          1. 7.3.8.1.1 VAC Over-voltage Protection (VAC_OVP)
          2. 7.3.8.1.2 VAC Under-voltage Protection (VAC_UVP)
          3. 7.3.8.1.3 Reverse Mode Over-voltage Protection (REV_OVP)
          4. 7.3.8.1.4 Reverse Mode Under-voltage Protection (REV_UVP)
          5. 7.3.8.1.5 DRV_SUP Under-voltage and Over-voltage Protection (DRV_OKZ)
          6. 7.3.8.1.6 REGN Under-voltage Protection (REGN_OKZ)
        2. 7.3.8.2 Thermal Shutdown (TSHUT)
      9. 7.3.9 Serial Interface
        1. 7.3.9.1 Data Validity
        2. 7.3.9.2 START and STOP Conditions
        3. 7.3.9.3 Byte Format
        4. 7.3.9.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 7.3.9.5 Target Address and Data Direction Bit
        6. 7.3.9.6 Single Write and Read
        7. 7.3.9.7 Multi-Write and Multi-Read
    4. 7.4 Device Functional Modes
      1. 7.4.1 Host Mode and Default Mode
      2. 7.4.2 Register Bit Reset
    5. 7.5 BQ25758A Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application (Buck-Boost configuration)
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 ACUV / ACOV Input Voltage Operating Window Programming
          2. 8.2.1.2.2 Switching Frequency Selection
          3. 8.2.1.2.3 Inductor Selection
          4. 8.2.1.2.4 Input (VAC) Capacitor
          5. 8.2.1.2.5 Output (VBAT) Capacitor
          6. 8.2.1.2.6 Sense Resistor (RAC_SNS and RBAT_SNS) and Current Programming
          7. 8.2.1.2.7 Converter Fast Transient Response
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Application (Buck-only configuration)
        1. 8.2.2.1 Design Requirements
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Packaging Information
    2. 13.2 Tape and Reel Information
    3. 13.3 Mechanical Data

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RRV|36
Thermal pad, mechanical data (Package|Pins)

7.3.3.3 REGN Regulator (REGN LDO)

The REGN LDO regulator provides a regulated bias supply for the IC and the TS external resistors. Additionally, REGN voltage can be used to drive the buck switching FETs directly by tying the DRV_SUP pin to REGN. The pull-up rail of PG, STAT can be connected to REGN as well. The REGN LDO is enabled when below conditions are valid:

  1. VAC voltage above VVAC_OK and converter operation is enabled in forward mode.
  2. BAT voltage above 3 V in Reverse mode and Reverse Mode is enabled (EN_REV = 1)

At high input voltages and/or large gate drive requirements, the power loss from gate driving via the REGN LDO can be excessive. This power for the gate drivers can be provided externally by directly driving the DRV_SUP pin with a high efficiency supply ranging from 4.5 V to 12 V. This supply should be able to provide at least 50 mA or more as required to drive the switching FET gate charge.

The power dissipation for driving the gates via the REGN LDO is: P R E G N = ( V A C - V R E G N ) × Q G T O T 1,2 × f S W , where QG(TOT)1,2 is the sum of the total gate charge for all switching FETs and fSW is the programmed switching frequency. The Safe Operating Area (SOA) below is based on a 1-W power loss limit.

BQ25758A REGN LDO Safe Operating Area (SOA) Figure 7-2 REGN LDO Safe Operating Area (SOA)