BQ29200 Datasheet, PDF (1/15 Pages) Texas Instruments – Voltage Protection with Automatic Cell Balance for 2-Series Cell Li-Ion Batteries

bq29200
bq29209
www.ti.com
SLUSA52 – JUNE 2010
Voltage Protection with Automatic Cell Balance for 2-Series Cell Li-Ion Batteries
Check for Samples: bq29200 , bq29209
FEATURES
1
• 2-Series Cell Secondary Protection
• Automatic Cell Imbalance Correction with
External Enable Control
– ±30 mV Enable, 0 mV Disable
Thresholds Typical
• External Capacitor-Controlled Delay Timer
• External Resistor-Controlled Cell Balance
Current
• Low Power Consumption I_CC < 3 µA Typical
(V_CELL(ALL) < V_PROTECT)
• High-Accuracy Overvoltage Protection:
– ±25 mV with T_A = 0°C to 60°C
• Fixed Overvoltage Protection Thresholds:
4.30 V, 4.35 V
• Small 8L DRB Package
APPLICATIONS
• 2^nd Level Protection in Li-Ion Battery Packs
– Netbook Computers
– Power Tools
– Portable Equipment and Instrumentation
– Battery Backup Systems
DESCRIPTION
The bq2920x device is a secondary overvoltage protection IC for two-series cell lithium-ion battery packs that
incorporates a high-accuracy precision overvoltage detection circuit and automatic cell imbalance correction.
The voltage of each cell in a two-series cell battery pack is compared to an internal reference voltage. If either
cell reaches an overvoltage condition, the bq2920x device starts a timer that provides a delay proportional to the
capacitance on the CD pin. Upon expiration of the internal timer, the OUT pin changes from low to high state.
If enabled, the bq2920x will perform automatic cell imbalance correction where the two cells are automatically
corrected for voltage imbalance by loading the cell with the higher charge voltage with a small balancing current.
When the cells are measured to be equal within nominally 0 mV, the load current is removed. It will be re-applied
if the imbalance exceeds nominally 30 mV. The cell mismatch correction circuitry is enabled by pulling the
CB_EN pin low, and disabled when CB_EN is pulled to VDD or greater than 2.2 V.
VC2 1
VC1 2
VC1_CB 3
CD 4
8 OUT
7 VDD
6 CB_EN
5 GND
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated