SLUS688H March   2006  – November 2015

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Options
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Dissipation Ratings
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  PWM Controller
      2. 8.3.2  Temperature Qualification
      3. 8.3.3  Battery Preconditioning (Precharge)
      4. 8.3.4  Battery Charge Current
      5. 8.3.5  Battery Voltage Regulation
      6. 8.3.6  Charge Termination And Recharge
      7. 8.3.7  Sleep Mode
      8. 8.3.8  Charge Status Outputs
      9. 8.3.9  PG Output
      10. 8.3.10 CE Input (Charge Enable)
      11. 8.3.11 Timer Fault Recovery
      12. 8.3.12 Output Overvoltage Protection (Applies to All Versions)
      13. 8.3.13 Battery Detection
        1. 8.3.13.1 Battery Detection Example
      14. 8.3.14 Current Sense Amplifier
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor, Capacitor, and Sense Resistor Selection Guidelines
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

6 Pin Configuration and Functions

RHL Package
20-Pin VQFN
Top View
bq24120 bq24123 bq24125 po_lus688.gif

Pin Functions

PIN I/O DESCRIPTION
NAME bq24120 bq24123 bq24125
BAT 14 14 14 I Battery voltage sense input. Bypass it with a capacitor to VSS if there are long inductive leads to battery.
CE 16 16 16 I Charger enable input. This active low input, if set high, suspends charge and places the device in the low-power sleep mode. Do not pull up this input to VTSB.
CELLS 13 I Available on parts with selectable output voltage. Ground or float for single-cell operation (4.2 V). For two-cell operation (8.4 V) pull up this pin with a resistor to VIN.
FB 13 I Output voltage analog feedback adjustment. Connect the output of a resistive voltage divider powered from the battery terminals to this node to adjust the output battery voltage regulation.
IN 3, 4 3, 4 3, 4 I Charger input voltage. Bypass it with a 10μF capacitor from IN to PGND.
ISET1 8 8 8 I/O Charger current set point 1 (fast charge). Use a resistor to ground to set this value.
ISET2 9 9 9 I/O Charge current set point 2 (precharge and termination), set by a resistor connected to ground.
N/C 13 – No connection. This pin must be left floating in the application.
OUT 1 1 1 O Charge current output inductor connection. Connect a zener TVS diode between OUT pin and PGND to clamp the voltage spike to protect the power MOSFETs during abnormal conditions.
20 20 20 O
PG 5 5 5 O Power-good status output (open drain). The transistor turns on when a valid VCC is detected. It is turned off in the sleep mode. PG can be used to drive a LED or communicate with a host processor.
PGND 17,18 17,18 17,18 Power ground input
SNS 15 15 15 I Charge current-sense input. Battery current is sensed via the voltage drop developed on this pin by an external sense resistor in series with the battery pack. A 0.1μF capacitor to VSS is required.
STAT1 2 2 2 O Charge status 1 (open-drain output). When the transistor turns on indicates charge in process. When it is off and with the condition of STAT2 indicates various charger conditions (See Table 1)
STAT2 19 19 19 O Charge status 2 (open-drain output). When the transistor turns on indicates charge is done. When it is off and with the condition of STAT1 indicates various charger conditions (See Table 1)
TS 12 12 12 I Temperature sense input. This input monitors its voltage against an internal threshold to determine if charging is allowed. Use an NTC thermistor and a voltage divider powered from VTSB to develop this voltage. (See Figure 9)
TTC 7 7 7 I Timer and termination control. Connect a capacitor from this node to VSS to set the bqSWITCHER timer. When this input is low, the timer and termination detection are disabled.
VCC 6 6 6 I Analog device input. A 0.1μF capacitor to VSS is required.
VSS 10 10 10 Analog ground input
VTSB 11 11 11 O TS internal bias regulator voltage. Connect capacitor (with a value between a 0.1μF and 1μF) between this output and VSS.
Exposed Thermal
Pad		 Pad Pad Pad There is an internal electrical connection between the exposed thermal pad and VSS. The exposed thermal pad must be connected to the same potential as the VSS pin on the printed circuit board. The power pad can be used as a star ground connection between VSS and PGND. A common ground plane may be used. VSS pin must be connected to ground at all times.