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

7.3.5 SYS Power Control (SYS_MODE bit control)

The device also offers the option to control SYS through the I2C SYS_MODE bits. These bits can force SYS to be supplied by BAT instead of IN (even if VIN > VBAT + VSLEEP), disconnect SYS from either supply, pull SYS down or leave it floating. The table below shows the device behavior based on SYS_MODE setting:

Table 7-2 Settings
SYS_MODE DESCRIPTION SYS SUPPLY SYS PULL-DOWN

00

Normal Operation

IN or BAT

Off except during HW reset

01

Force BAT power (USB Suspend)

BAT

Off except during HW reset

10

SYS Off –Floating

None

Off

11

SYS Off – Pulled Down

None

On

SYS_MODE = 00

This is the default state / normal operation of the device. SYS will be powered from IN if VIN > VUVLO, VIN > VBAT + VSLEEP, and VIN < VIN_OVP. SYS will powered by BAT if these conditions are not met. SYS will only be disconnected from IN or BAT and pulled down when a HW Reset occurs or the device goes into Ship mode.

SYS_MODE = 01

When this configuration is set, SYS will be powered by BAT if VBAT > VBUVLO regardless of VIN state. This allows the host to minimize the current draw from the adapter while it is still connected as needed in the system.If SYS_MODE = 01 is set while VBAT < VBUVLO, the SYS_MODE = 01 setting will be ignored and the device will go to SYS_MODE = 00. In the same manner, if the adapter (VIN) is removed and then connected the device will also switch to SYS_MODE=00. This prevents the device from needing a POR in order to restore power to the system thereby allowing battery charging and providing a true USB suspend mode. If SYS_MODE = 01 is set during charging, charging will be stopped and the battery will start to provide power to SYS as needed. The behavior is similar to that when the input adapter is disconnected.

SYS_MODE = 10

When this configuration is set, SYS will be disconnected and left floating. The digital remains on and active. When floating, SYS can only be forced to a voltage up to VBAT level. Toggling VIN(VIN <VINUVLO) will reset the SYS_MODE to 00.

SYS_MODE = 11

When this configuration is set, SYS will be disconnected and pulled down to ground. Toggling VIN will reset the SYS_MODE to 00.