SLUSCA6B March   2016  – March 2017

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (Continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and 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 Functional Block Diagram
    2. 9.2 Feature Description
      1. 9.2.1  Device Power-On-Reset (POR)
      2. 9.2.2  Device Power Up from Battery without Input Source
      3. 9.2.3  Device Power Up from Input Source
        1. 9.2.3.1 Power Up REGN Regulation (LDO)
        2. 9.2.3.2 Poor Source Qualification
        3. 9.2.3.3 Input Source Type Detection
          1. 9.2.3.3.1 D+/D- Detection Sets Input Current Limit (bq25898D)
          2. 9.2.3.3.2 PSEL Pin Sets Input Current Limit (bq25898)
          3. 9.2.3.3.3 Force Input Current Limit Detection
        4. 9.2.3.4 Input Voltage Limit Threshold Setting (VINDPM Threshold)
        5. 9.2.3.5 Converter Power-Up
      4. 9.2.4  Input Current Optimizer (ICO)
      5. 9.2.5  Boost Mode Operation from Battery
      6. 9.2.6  Power Path Management
        1. 9.2.6.1 Narrow VDC Architecture
        2. 9.2.6.2 Dynamic Power Management
        3. 9.2.6.3 Supplement Mode
      7. 9.2.7  Battery Charging Management
        1. 9.2.7.1 Autonomous Charging Cycle
        2. 9.2.7.2 Battery Charging Profile
        3. 9.2.7.3 Charging Termination
        4. 9.2.7.4 Resistance Compensation (IRCOMP)
        5. 9.2.7.5 Thermistor Qualification
          1. 9.2.7.5.1 JEITA Guideline Compliance in Charge Mode
          2. 9.2.7.5.2 Cold/Hot Temperature Window in Boost Mode
        6. 9.2.7.6 Charging Safety Timer
      8. 9.2.8  Battery Monitor
      9. 9.2.9  Status Outputs (PG, STAT, and INT)
        1. 9.2.9.1 Power Good Indicator (PG)
        2. 9.2.9.2 Charging Status Indicator (STAT)
        3. 9.2.9.3 Interrupt to Host (INT)
      10. 9.2.10 BATFET (Q4) Control
        1. 9.2.10.1 BATFET Disable Mode (Shipping Mode)
        2. 9.2.10.2 BATFET Enable (Exit Shipping Mode)
        3. 9.2.10.3 BATFET Full System Reset
      11. 9.2.11 Current Pulse Control Protocol
      12. 9.2.12 Input Current Limit on ILIM
      13. 9.2.13 Thermal Regulation and Thermal Shutdown
        1. 9.2.13.1 Thermal Protection in Buck Mode
          1. 9.2.13.1.1 Thermal Protection in Boost Mode
      14. 9.2.14 Voltage and Current Monitoring in Buck and Boost Mode
        1. 9.2.14.1 Voltage and Current Monitoring in Buck Mode
          1. 9.2.14.1.1 Input Overvoltage (ACOV)
          2. 9.2.14.1.2 System Overvoltage Protection (SYSOVP)
        2. 9.2.14.2 Voltage and Current Monitoring in Boost Mode
          1. 9.2.14.2.1 VBUS Overcurrent Protection
          2. 9.2.14.2.2 Boost Mode Overvoltage Protection
      15. 9.2.15 Battery Protection
        1. 9.2.15.1 Battery Overvoltage Protection (BATOVP)
        2. 9.2.15.2 Battery Over-Discharge Protection
        3. 9.2.15.3 System Overcurrent Protection
      16. 9.2.16 Serial Interface
        1. 9.2.16.1 Data Validity
        2. 9.2.16.2 START and STOP Conditions
        3. 9.2.16.3 Byte Format
        4. 9.2.16.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 9.2.16.5 Slave Address and Data Direction Bit
        6. 9.2.16.6 Single Read and Write
        7. 9.2.16.7 Multi-Read and Multi-Write
    3. 9.3 Device Functional Modes
      1. 9.3.1 Host Mode and Default Mode
    4. 9.4 Register Map
      1. 9.4.1  REG00
      2. 9.4.2  REG01
      3. 9.4.3  REG02
      4. 9.4.4  REG03
      5. 9.4.5  REG04
      6. 9.4.6  REG05
      7. 9.4.7  REG06
      8. 9.4.8  REG07
      9. 9.4.9  REG08
      10. 9.4.10 REG09
      11. 9.4.11 REG0A
      12. 9.4.12 REG0B
      13. 9.4.13 REG0C
      14. 9.4.14 REG0D
      15. 9.4.15 REG0E
      16. 9.4.16 REG0F
      17. 9.4.17 REG10
      18. 9.4.18 REG11
      19. 9.4.19 REG12
      20. 9.4.20 REG13
      21. 9.4.21 REG14
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application Diagram
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Inductor Selection
        2. 10.2.2.2 Buck Input Capacitor
        3. 10.2.2.3 System Output Capacitor
      3. 10.2.3 Application Curves
    3. 10.3 System Example
  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 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • YFF|42
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

10.1 Application Information

A typical application consists of the device configured as an I2C controlled power path management device and a single cell battery charger for Li-Ion and Li-polymer batteries used in a wide range of smartphones and other portable devices. It integrates an input reverse-block FET (RBFET, Q1), high-side switching FET (HSFET, Q2), low-side switching FET (LSFET, Q3), and BATFET (Q4) between the system and battery. The device also integrates a bootstrap diode for the high-side gate drive.

10.2 Typical Application Diagram

bq25898 bq25898D app_circuit2_bq25898D_slusca6.gif
VREF is the pull up voltage of I2C communication interface
Figure 49. bq25898D Application Diagram with PSEL with Interface and USB On-The-Go (OTG)

10.2.1 Design Requirements

For this design example, use the parameters shown in Table 30.

Table 30. Design Parameters

PARAMETER VALUE
Input voltage range 3.9 V to 14 V
Input current limit 1.5 A
Fast charge current 4032 mA
Output voltage 4.208 V

10.2.2 Detailed Design Procedure

10.2.2.1 Inductor Selection

The device has 1.5 MHz switching frequency to allow the use of small inductor and capacitor values. The Inductor saturation current should be higher than the charging current (ICHG) plus half the ripple current (IRIPPLE):

Equation 5. bq25898 bq25898D eq3_Ibat_slusbu7.gif

The inductor ripple current depends on input voltage (VBUS), duty cycle (D = VBAT/VVBUS), switching frequency (fs) and inductance (L):

Equation 6. bq25898 bq25898D eq4_Iripple_slusbu7.gif

The maximum inductor ripple current happens with D = 0.5 or close to 0.5. Usually inductor ripple is designed in the range of (20–40%) maximum charging current as a trade-off between inductor size and efficiency for a practical design.

10.2.2.2 Buck Input Capacitor

Input capacitor should have enough ripple current rating to absorb input switching ripple current. The worst case RMS ripple current is half of the charging current when duty cycle is 0.5. If the converter does not operate at 50% duty cycle, then the worst case capacitor RMS current IPMID occurs where the duty cycle is closest to 50% and can be estimated by Equation 7:

Equation 7. bq25898 bq25898D eq5_Icin_slusbu7.gif

Low ESR ceramic capacitor such as X7R or X5R is preferred for input decoupling capacitor and should be placed to the drain of the high side MOSFET and source of the low side MOSFET as close as possible. Voltage rating of the capacitor must be higher than normal input voltage level. 25 V rating or higher capacitor is preferred for up to 14-V input voltage. 8.2-μF capacitance is suggested for typical of 3 A – 5 A charging current.

10.2.2.3 System Output Capacitor

Output capacitor also should have enough ripple current rating to absorb output switching ripple current. The output capacitor RMS current ICOUT is given:

Equation 8. bq25898 bq25898D eq6_Icout_slusbu7.gif

The output capacitor voltage ripple can be calculated as follows:

Equation 9. bq25898 bq25898D eq7_Vout_slusbu7.gif

At certain input/output voltage and switching frequency, the voltage ripple can be reduced by increasing the output filter LC. The charger device has internal loop compensator. To get good loop stability, 1-µH and minimum of 20-µF output capacitor is recommended. The preferred ceramic capacitor is 6V or higher rating, X7R or X5R.

10.2.3 Application Curves

bq25898 bq25898D tek00072_Fig50_slusca6.png
VBAT = 3.2 V, VBUS = 5 V
Figure 50. Power Up with Charge Disabled
bq25898 bq25898D tek00079_FIG52_slusca6.png
VBUS = 5 V
Figure 52. Charge Enable
bq25898 bq25898D tek00093_FIG54_slusca6.png
VBUS = 5 V IIN = 3 A Charge Disable
Figure 54. Input Current DPM Response without Battery
bq25898 bq25898D tek00096_FIG56_slusca6.png
VBUS = 12 V VBAT = 3.8 V ICHG = 3 A
Figure 56. PWM Switching Waveform
bq25898 bq25898D tek00103_FIG58_slusca6.png
VBAT = 3.8 V ILOAD = 1 A
Figure 58. Boost Mode Switching Waveform
bq25898 bq25898D tek00082_FIG60_slusca6.png
VBAT = 3.2 V VBUS = 12 V
Figure 60. Power Up with Charge Disabled
bq25898 bq25898D tek00081_FIG62_slusca6.png
VBUS = 12 V
Figure 62. Charge Disable
bq25898 bq25898D tek00084_FIG64_slusca6.png
VBUS = 12 V ISYS = 7 mA Charge Disable
Figure 64. PFM Switching Waveform
bq25898 bq25898D tek00073_FIG51_slusca6.png
VBAT = 3.2 V, VBUS = 5 V
Figure 51. Power Up with Charge Enabled
bq25898 bq25898D tek00076_FIG53_slusca6.png
VBUS = 5 V
Figure 53. Charge Disable
bq25898 bq25898D tek00095_FIG55_slusca6.png
VBUS = 9 V IIN = 1.5 A VBAT = 3.8 V
ICHG = 2 A ISYS = 0 A - 4 A
Figure 55. Load Transient During Supplement Mode
bq25898 bq25898D tek00102_FIG57_slusca6.png
VBUS = 9V ISYS = 20 mA, Charge Disable
No Battery
Figure 57. PFM Switching Waveform
bq25898 bq25898D tek00091_FIG59_slusca6.png
VBAT = 3.8 V ILOAD = 0 A - 1 A
Figure 59. Boost Mode Load Transient
bq25898 bq25898D tek00080_FIG61_slusca6.png
VBUS = 12 V
Figure 61. Charge Enable
bq25898 bq25898D tek00086_FIG63_slusca6.png
VBUS = 12 V VBAT = 3.8 V ICHG = 3 A
Figure 63. PWM Switching Waveform

10.3 System Example

bq25898 bq25898D app_circuit2_bq25898_slusca6.gif
C1 = 8.2µF (OTG ≤ 1.8A) or 20µF (OTG ≤ 2.4A) is recommended
Figure 65. bq25898 with PSEL Interface and USB On-The-Go (OTG)