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

7.3.15.1 F/S Mode Protocol

The master initiates data transfer by generating a start condition. The start condition is when a high-to-low transition occurs on the SDA line while SCL is high, as shown in Figure 7-4. All I2C-compatible devices should recognize a start condition.

BQ21088 START and STOP ConditionFigure 7-4 START and STOP Condition

The master then generates the SCL pulses, and transmits the 8-bit address and the read/write direction bit R/W on the SDA line. During all transmissions, the master ensures that data is valid. A valid data condition requires the SDA line to be stable during the entire high period of the clock pulse (see Figure 7-5). All devices recognize the address sent by the master and compare it to their internal fixed addresses. Only the slave device with a matching address generates an acknowledge (see Figure 7-6) by pulling the SDA line low during the entire high period of the ninth SCL cycle. Upon detecting this acknowledge, the master knows that communication link with a slave has been established.

BQ21088 Bit Transfer on the Serial InterfaceFigure 7-5 Bit Transfer on the Serial Interface

The master generates further SCL cycles to either transmit data to the slave (R/W bit 1) or receive data from the slave (R/W bit 0). In either case, the receiver needs to acknowledge the data sent by the transmitter. So an acknowledge signal can either be generated by the master or by the slave, depending on which one is the receiver. The 9-bit valid data sequences consisting of 8-bit data and 1-bit acknowledge can continue as long as necessary. To signal the end of the data transfer, the master generates a stop condition by pulling the SDA line from low to high while the SCL line is high (see Figure 7-4). This releases the bus and stops the communication link with the addressed slave. All I2C compatible devices must recognize the stop condition. Upon the receipt of a stop condition, all devices know that the bus is released, and wait for a start condition followed by a matching address. If a transaction is terminated prematurely, the master needs sending a STOP condition to prevent the slave I2C logic from remaining in an incorrect state. Attempting to read data from register addresses not listed in this section wil result in FFh being read out.

BQ21088 Ackowledge on the I2C BusFigure 7-6 Ackowledge on the I2C Bus
BQ21088 Bus ProtocolFigure 7-7 Bus Protocol