SLUSFR2 November   2024 BQ21088

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Thermal Information
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 Battery Charging Process
        1. 7.1.1.1 Trickle Charge
        2. 7.1.1.2 Pre-Charge
        3. 7.1.1.3 Fast Charge
        4. 7.1.1.4 Termination
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Input Voltage Based Dynamic Power Management (VINDPM)
      2. 7.3.2  Dynamic Power Path Management Mode (DPPM)
      3. 7.3.3  Battery Supplement Mode
      4. 7.3.4  Sleep Mode
      5. 7.3.5  SYS Power Control (SYS_MODE bit control)
        1. 7.3.5.1 SYS Pulldown Control
      6. 7.3.6  SYS Regulation
      7. 7.3.7  ILIM Control
      8. 7.3.8  Protection Mechanisms
        1. 7.3.8.1 Input Overvoltage Protection
        2. 7.3.8.2 Battery Undervoltage Lockout
        3. 7.3.8.3 Battery Overcurrent Protection
        4. 7.3.8.4 System Overvoltage Protection
        5. 7.3.8.5 System Short Protection
        6. 7.3.8.6 Thermal Protection and Thermal Regulation
        7. 7.3.8.7 Safety Timer and Watchdog Timer
      9. 7.3.9  Pushbutton Wake and Reset Input
        1. 7.3.9.1 Pushbutton Wake or Short Button Press Functions
        2. 7.3.9.2 Pushbutton Reset or Long Button Press Functions
      10. 7.3.10 15-Second Timeout for HW Reset
      11. 7.3.11 Hardware Reset
      12. 7.3.12 Software Reset
      13. 7.3.13 Interrupt Indicator (/INT) Pin
      14. 7.3.14 External NTC Monitoring (TS)
        1. 7.3.14.1 TS Biasing and Function
      15. 7.3.15 I2C Interface
        1. 7.3.15.1 F/S Mode Protocol
    4. 7.4 Device Functional Modes
    5. 7.5 Register Maps
      1. 7.5.1 I2C Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
      4. 8.2.4 Application Curves
  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 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • YBG|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.6 SYS Regulation

The BQ21088 includes a SYS voltage regulation loop. By regulating the SYS voltage the device prevents downstream devices connected to SYS from being exposed to voltages as high as VIN_OVP. SYS regulation is only active when VIN > VUVLO, VIN > VBAT + VSLEEP and VIN < VIN_OVP rather meeting the VIN_Powergood condition.

SYS voltage regulation target can be controlled through the SYS_REG_CTRL_2:0 bits on the SYS_REG Register to either track the battery, set to a fixed voltage, or enable pass through modes.

In battery tracking mode, the minimum voltage is at VMINSYS value for battery < 3.6 V. As battery voltage increases- VSYS is regulated to 225 mV above battery. If VIN <VMINSYS and VIN_Powergood is still active, then the SYS will be in dropout.

In the fixed voltage mode, the SYS voltage is regulated to a target set by the host ranging from 4.4 V to 4.9 V . If VIN voltage is less than the SYS target voltage, then the device will be in dropout mode.

Table 7-4 Regulation
SYS_REG_CTRLVSYS TARGET

000

VBAT + 225 mV (3.8 V minimum)

001

4.4

010 (default)

4.5

011

4.6

100

4.7

101

4.8

110

4.9

111

Passthrough