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)

7.1 Overview

BQ25758A is a wide voltage, bidirectional switched-mode synchronous buck-boost controller. The device offers high-efficiency voltage conversion over a wide voltage range with output CC-CV control. The device integrates all the loop compensation and 5-V gate drivers for the buck-boost converter, thereby providing a high density solution with ease of use. The switching frequency of the device can be programmed or forced to follow an external clock frequency via the FSW_SYNC pin. While switching under light-load, the device offers an optional Pulse Frequency Modulation (PFM) scheme to increase efficiency. In reverse mode, the device draws power from the output supply and regulates the input terminal voltage with an added constant current loop for protection.

Besides the I2C host-controlled mode, the device also supports programmable hardware limits. Input current, and output current regulation targets can be set with single resistor on the IIN, and IOUT pins, respectively. By default, the device is programmed to provide 5-V output, and the target output voltage can be adjusted via the VOUT_REG register bits. Forward switching function is controlled via the CE pin.

The input operating window is programmed via the ACUV and ACOV pins. When the input voltage is outside the programmed window, the device automatically stops switching, and the PG pin pulls HIGH.

The BQ25758A provides various safety features including over-voltage and over-current protections on the input and the output. The thermal shutdown prevents operating when the junction temperature exceeds the TSHUT limit.

The device has two status pins (STAT, and PG) to indicate the switcher and input voltage status. These pins can be used to drive LEDs or communicate with a host processor. If needed, these pins can also be used as general purpose indicators and their status controlled directly by the I2C interface. In addition, the CE pin can also be used as a general purpose indicator. The INT pin immediately notifies host when the device status changes, including faults.

The device also provides a 16-bit analog-to-digital converter (ADC) for monitoring input current, output current and input/output/thermistor voltages (IAC, IOUT, VAC, VOUT, TS).

The device comes with a 36-pin 5-mm × 6-mm QFN package with 0.5-mm pin pitch.