SLUSD08A May   2017  – January 2018

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Ship Mode
        1. 9.3.1.1 Ship Mode Entry and Exit
      2. 9.3.2  High Impedance Mode
      3. 9.3.3  Active Battery Only Connected
      4. 9.3.4  Voltage Based Battery Monitor
      5. 9.3.5  Sleep Mode
      6. 9.3.6  Input Voltage Based Dynamic Power Management (VIN(DPM))
      7. 9.3.7  Input Overvoltage Protection and Undervoltage Status Indication
      8. 9.3.8  Battery Charging Process and Charge Profile
      9. 9.3.9  Dynamic Power Path Management Mode
      10. 9.3.10 Battery Supplement Mode
      11. 9.3.11 Default Mode
      12. 9.3.12 Termination and Pre-Charge Current Programming by External Components (IPRETERM)
      13. 9.3.13 Input Current Limit Programming by External Components (ILIM)
      14. 9.3.14 Charge Current Programming by External Components (ISET)
      15. 9.3.15 Safety Timer and Watchdog Timer
      16. 9.3.16 External NTC Monitoring (TS)
      17. 9.3.17 Thermal Protection
      18. 9.3.18 Typical Application Power Dissipation
      19. 9.3.19 Status Indicators (PG and INT)
      20. 9.3.20 Chip Disable (CD)
      21. 9.3.21 Buck (PWM) Output
      22. 9.3.22 Load Switch / LDO Output and Control
      23. 9.3.23 Manual Reset Timer and Reset Output (MR and RESET)
    4. 9.4 Device Functional Modes
    5. 9.5 Programming
      1. 9.5.1 Serial Interface Description
      2. 9.5.2 F/S Mode Protocol
    6. 9.6 Register Maps
      1. 9.6.1  Status and Ship Mode Control Register
        1. Table 12. Status and Ship Mode Control Register
      2. 9.6.2  Faults and Faults Mask Register
        1. Table 13. Faults and Faults Mask Register
      3. 9.6.3  TS Control and Faults Masks Register
        1. Table 14. TS Control and Faults Masks Register, Memory Location 0010
      4. 9.6.4  Fast Charge Control Register
        1. Table 15. Fast Charge Control Register
      5. 9.6.5  Termination/Pre-Charge and I2C Address Register
        1. Table 16. Termination/Pre-Charge and I2C Address Register
      6. 9.6.6  Battery Voltage Control Register
        1. Table 17. Battery Voltage Control Register
      7. 9.6.7  SYS VOUT Control Register
        1. Table 18. SYS VOUT Control Register
      8. 9.6.8  Load Switch and LDO Control Register
        1. Table 20. Load Switch and LDO Control Register
      9. 9.6.9  Push-button Control Register
        1. Table 21. Push-button Control Register
      10. 9.6.10 ILIM and Battery UVLO Control Register
        1. Table 22. ILIM and Battery UVLO Control Register, Memory Location 1001
      11. 9.6.11 Voltage Based Battery Monitor Register
        1. Table 23. Voltage Based Battery Monitor Register, Memory Location 1010
      12. 9.6.12 VIN_DPM and Timers Register
        1. Table 24. VIN_DPM and Timers Register
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Default Settings
        2. 10.2.2.2 Choose the Correct Inductance and Capacitance
        3. 10.2.2.3 Calculations
          1. 10.2.2.3.1 Program the Fast Charge Current (ISET)
          2. 10.2.2.3.2 Program the Input Current Limit (ILIM)
          3. 10.2.2.3.3 Program the Pre-charge/termination Threshold (IPRETERM)
          4. 10.2.2.3.4 TS Resistors (TS)
      3. 10.2.3 Application Performance Curves
        1. 10.2.3.1 Charger Curves
        2. 10.2.3.2 SYS Output Curves
        3. 10.2.3.3 Load Switch and LDO Curves
        4. 10.2.3.4 LS/LDO Output Curves
        5. 10.2.3.5 Timing Waveforms Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.4 Voltage Based Battery Monitor

The device implements a simple voltage battery monitor which can be used to determine the depth of discharge. Prior to entering High-Z mode, the device will initiate a VBMON reading. The host can read the latched value for the no-load battery voltage, or initiate a reading using VBMON_READ to see the battery voltage under a known load. The register will be updated and can be read 2ms after a read is initiated. The VBMON voltage threshold is readable with 2% increments with ±1.5% accuracy between 60% and 100% of VBATREG using the VBMON_TH registers.  Reading the value during charge is possible, but for the most accurate battery voltage indication, it is recommended to disable charge, initiate a read, and then re-enable charge.

A typical discharge profile for a Li-Ion battery is shown in Table 2. The specific battery to be used in the application should be fully characterized to determine the thresholds that will indicate the appropriate battery status to the user. Two typical examples are shown below, assuming the VBMON reading is taken with no load on the battery.

This function enables a simple 5-bar status indicator with the following typical performance with different VBATREG settings:

Table 2. Discharge Profile for a Li-Ion Battery

VBATREG BATTERY FULL 95% to 65%
REMAINING CAPACITY 		65% to 35%
REMAINING CAPACITY 		35% to 5%
REMAINING CAPACITY 		BATTERY EMPTY
4.35 V VBMON > 90% VBMON = 88% VBMON = 86% VBMON = 84% VBMON < 82%
4.2 V VBMON > 98% VBMON = 94% or 96% VBMON = 90% or 92% VBMON = 86% or 88% VBMON < 84%
bq25120A voltage_battery_monitor_slusbz9.gifFigure 17. Voltage Battery Monitor