Features: ` 3- or 4-Cell Series Protection Control
` Autonomous Overcurrent and Short Circuit Protection
` Provides Individual Cell Voltages to Battery Management Host
` Integrated Cell Balancing Control
` I2C Compatible User Interface Allows Access to Battery Information
` User Control to Initiate Protection
` Integrated 3.3-V 25-mA LDO
` Programmable Shutdown and Brownout Control
` Provides Drive for Three External FETs
` Low Supply Current of 140 A Typical
` Programmable Threshold and Delay for Short-Circuit Current Protection
` Provides Drive for Three External FETs
` Can Directly Interface With bq2083/5 for Complete Battery Management SolutionApplication· Notebook Computer Battery Packs
· Test EquipmentPinout
Specifications
| Supply voltage range(2) |
VCC, VPACK |
−0.3 V to 34 V |
| Input voltage range |
VC1, VC2, VC3, VC4, VBAT |
−0.3 V to 34 V |
| VC5, SR1, SR2 |
−1 V to 1 V |
| VC1 to VC2, VC2 to VC3, VC3 to VC4, VC4 to VC5 |
−0.3 V to 8.5 V |
| CLK-IN, SCLK, SDATA |
−0.3 V to 7 V |
| CNTL |
−0.3 V to 34 V |
| Output voltage range |
DSG, CHG, PCHG |
−0.3 V to VCC |
| LEDOUT, TOUT, SCLK, SDATA, VCELL, XALERT |
−0.3 V to 7 V |
| Current for cell balancing |
10 mA |
| Continuous total power dissipation |
See Dissipation Rating Table |
| ESD rating(3) |
HBM |
1.5 kV |
| CDM |
250 V |
| MM |
50 V |
| Operating free-air temperature range, TA |
−25 to 85 |
| Storage temperature range, Tstg |
−65 to 150 |
| Lead temperature (soldering, 10 s) |
260 |
(1) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) All voltages are with respect to ground of this device except VCn-VC(n+1), where n = 1, 2, 3, 4 cell voltage.
(3) Design considerations should be made with respect to excessive ESD.
DescriptionThe bq29311 is a three- or four-cell lithium-ion battery pack protection analog front end (AFE) IC that incorporates a 3.3-V 25-mA low-dropout regulator (LDO) and an I2C compatible interface to extract battery parameters such as cell voltages and control output status. Other parameters, such as overcurrent protection threshold and delay, can also be programmed into the bq29311 to increase the flexibility of the battery management system.
The bq29311 provides safety protection in overcurrent, short circuit, overvoltage, and undervoltage conditions via control from the battery management host. In overcurrent and short-circuit conditions the bq29311 can directly activate the FET drive as a secondary proection level. The communications interface allows the host to control and observe the current status of the protection, to set overcurrent and overload levels, to set the overcurrent and overload blanking delay time, short-circuit threshold levels, and short-circuit blanking delay time, and to program for the VREG shutdown voltage and brownout-detection thresholds.
Each cell of BQ29311 is balanced by a discharge path, which is enabled by the internal control registers accessible through the I2C compatible interface. The maximum current is set by an external series resistor with an absolute maximum value of 10 mA discharge current per cell.
BQ29311 Data Sheet
