BQ77910 Datasheet, PDF (1/56 Pages) Texas Instruments – Stand-Alone Multi-Cell Lithium-Ion/Polymer Precision Protectors

bq77910
www.ti.com
SLUSA07B – AUGUST 2010 – REVISED MAY 2011
Stand-Alone Multi-Cell Lithium-Ion/Polymer Precision Protectors
Check for Samples: bq77910
FEATURES
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• 4-, 5-, 6-, 7-, 8-, 9-, or 10 Series Cell Protection
• Individual Cell-Voltage Monitoring
• Low-Side NMOS FET Drive for Charge and
Discharge Control
• Compatible With 1-mΩ Current-Sense Resistor
• Supply-Voltage Range From 5.6 V to 50 V
• Integrated 3.3-V Micro-Power LDO Regulator
• Low Supply Current
– Normal Mode: 50 µA, Typical
– Shutdown Mode, LDO OFF: 3 µA, Typical
• 38-Pin TSSOP Package
• Internal 50-mA Automatic Cell Balancing
APPLICATIONS
• Cordless Power Tools
• Cordless Lawn Equipment
• Electric Bikes
• UPS
• Medical Equipment
• Light Electric Vehicles (LEV)
DESCRIPTION
The bq77910 precision protector is a complete
stand-alone, self-contained battery-protection and
cell-balancing device intended for Li-ion/polymer
battery packs.
The bq77910 monitors 4 to 10 series individual cell
voltages and provides fast-acting outputs which may
be used to drive N-channel MOSFETs to interrupt the
power path. Activation delays and recovery methods
for each safety condition are fully programmable in
non-volatile memory.
Automatic cell balancing is provided using internal
50-mA cell circuits. A robust balancing algorithm
ensures optimum performance by maintaining all cell
voltages in balance. Balancing may be configured to
operate at all times, only during charge, or can be
disabled completely.
Additional advanced safety features of the bq77910
include the ability to control split power-path
MOSFETs, an open-cell sense-line detection
mechanism, and the ability to detect an open or
shorted external temperature sensor.
Programmable Protection Functions
• Wide range of programmable detection thresholds
and delay times
• Configurable for multiple cell types and application
requirements:
– Cell overvoltage
– Cell undervoltage
– Pack discharge overcurrent
– Pack discharge short circuit
– Pack charge short-circuit current
• Variable gain (×1 or ×5) current-sense circuit
– Compatible with a wide range of current-sense
resistors (1 mΩ to 5 mΩ typical) sized for
application requirements
Fixed Hardware Protection Functions
• Preset overtemperature protections
• Open-cell detection
• Open and shorted thermistor detection
• Brownout protection quickly shuts off FETs under
low battery conditions to avoid FET overheating
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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.
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