SLUSET4B December   2022  – March 2024 BQ25758

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 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 Device Power-On-Reset
      2. 6.3.2 Device Power-Up From Battery Without Input Source
      3. 6.3.3 Device Power Up from Input Source
        1. 6.3.3.1 VAC Operating Window Programming (ACUV and ACOV)
        2. 6.3.3.2 MODE Pin Configuration
        3. 6.3.3.3 REGN Regulator (REGN LDO)
        4. 6.3.3.4 Compensation-Free Buck-Boost Converter Operation
          1. 6.3.3.4.1 Light-Load Operation
        5. 6.3.3.5 Switching Frequency and Synchronization (FSW_SYNC)
        6. 6.3.3.6 Device HIZ Mode
      4. 6.3.4 Power Management
        1. 6.3.4.1 Output Voltage Programming (VOUT_REG)
        2. 6.3.4.2 Output Current Programming (IOUT pin and IOUT_REG)
        3. 6.3.4.3 Dynamic Power Management: Input Voltage and Input Current Regulation
          1. 6.3.4.3.1 Input Current Regulation
            1. 6.3.4.3.1.1 IIN Pin
          2. 6.3.4.3.2 Input Voltage Regulation
        4. 6.3.4.4 Bypass Mode
      5. 6.3.5 Bidirectional Power Flow and Programmability
      6. 6.3.6 Integrated 16-Bit ADC for Monitoring
      7. 6.3.7 Status Outputs (PG, STAT and INT)
        1. 6.3.7.1 Power Good Indicator (PG)
        2. 6.3.7.2 Interrupt to Host (INT)
      8. 6.3.8 Protections
        1. 6.3.8.1 Voltage and Current Monitoring
          1. 6.3.8.1.1 VAC Over-voltage Protection (VAC_OVP)
          2. 6.3.8.1.2 VAC Under-voltage Protection (VAC_UVP)
          3. 6.3.8.1.3 Reverse Mode Over-voltage Protection (REV_OVP)
          4. 6.3.8.1.4 Reverse Mode Under-voltage Protection (REV_UVP)
          5. 6.3.8.1.5 DRV_SUP Under-voltage and Over-voltage Protection (DRV_OKZ)
          6. 6.3.8.1.6 REGN Under-voltage Protection (REGN_OKZ)
        2. 6.3.8.2 Thermal Shutdown (TSHUT)
      9. 6.3.9 Serial Interface
        1. 6.3.9.1 Data Validity
        2. 6.3.9.2 START and STOP Conditions
        3. 6.3.9.3 Byte Format
        4. 6.3.9.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 6.3.9.5 Target Address and Data Direction Bit
        6. 6.3.9.6 Single Write and Read
        7. 6.3.9.7 Multi-Write and Multi-Read
    4. 6.4 Device Functional Modes
      1. 6.4.1 Host Mode and Default Mode
      2. 6.4.2 Register Bit Reset
    5. 6.5 BQ25758 Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Typical Application (Buck-Boost configuration)
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 ACUV / ACOV Input Voltage Operating Window Programming
          2. 7.2.1.2.2 Switching Frequency Selection
          3. 7.2.1.2.3 Inductor Selection
          4. 7.2.1.2.4 Input (VAC) Capacitor
          5. 7.2.1.2.5 Output (VBAT) Capacitor
          6. 7.2.1.2.6 Sense Resistor (RAC_SNS and RBAT_SNS) and Current Programming
          7. 7.2.1.2.7 Converter Fast Transient Response
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Typical Application (Buck-only configuration)
        1. 7.2.2.1 Design Requirements
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

6.3.3.4 Compensation-Free Buck-Boost Converter Operation

The device integrates all the loop compensation, thereby providing a high density solution with ease of use.

The converter employs a synchronous buck-boost converter that allows conversion from a wide range of input voltage sources. The converter operates in buck, buck-boost or boost mode. The converter can operate uninterruptedly and continuously across the three operation modes. During buck-boost mode, the converter alternates a SW1 pulse with a SW2 pulse, with effective switching frequency interleaved among these pulses for highest efficiency operation.

During boost mode operation, the HS FET is forced to turn on for 225 ns in each switching cycle to ensure inductor energy is delivered to the output, effectively limiting the maximum boosting ratio. For example, when device is configured to switch at 500 kHz, the switching period is 2 μs, yielding a duty cycle limit of (1 - 0.225 μs/2 μs) = 88.75%. Given a 5-V input, this translates to a maximum 44-V output assuming 100% efficiency. The true output will be lower than this ideal limit. At lower switching frequencies, the maximum duty cycle increases, making the limitation less significant.

Table 6-2 Switching MOSFET Operation
MODE BUCK BUCK-BOOST BOOST
HS BUCK FET Switching at fSW Switching (fSW interleaved between SW1 and SW2) ON
LS BUCK FET Switching at fSW Switching (fSW interleaved between SW1 and SW2) OFF
LS BOOST FET OFF Switching (fSW interleaved between SW1 and SW2) Switching at fSW
HS BOOST FET ON Switching (fSW interleaved between SW1 and SW2) Switching at fSW