BQ76925_15 Datasheet, PDF (1/43 Pages) Texas Instruments – Host-Controlled Analog Front

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bq76925
SLUSAM9C – JULY 2011 – REVISED OCTOBER 2015
bq76925 Host-Controlled Analog Front End for 3-Series to 6-Series Cell Li-Ion/Li-Polymer
Battery Protection and Gas Gauging Applications
1 Features
•1 Analog Interface for Host Cell Measurement
– Cell Input MUX, Level Shifter, and Scaler
– 1.5-/ 3.0-V Low-Drift, Calibrated Reference
Allows Accurate Analog-to-Digital Conversions
• Analog Interface for Host Current Measurement
– Variable Gain Current Sense Amplifier
Capable of Operation with 1-mΩ Sense
Resistor
• Switchable Thermistor Bias Output for Host
Temperature Measurements
• Overcurrent Comparator With Dynamically
Adjustable Threshold
– Alerts Host to Potential Overcurrent Faults
– Wakes up Host on Load Connect
• Integrated Cell Balancing FETs
– Individual Host Control
– 50 mA per Cell Balancing Current
• Supports Cell Sense-Line Open Wire Detection
• Integrated 3.3-V Regulator for Powering Micro-
Controller and/or LEDs
• I²C Interface for Host Communications
– Optional Packet CRC for Robust Operation
• Supply Voltage Range From 4.2 to 26.4 V
• Low Power Consumption
– 40 µA Typical in Normal Mode
– 1.5 µA Maximum in Sleep Mode
• 20-Pin TSSOP or 24-Pin VQFN Package
2 Applications
• Primary Protection in Li-Ion Battery Packs
– Cordless Power Tools
– Light Electric Vehicles (E-Bike, Scooter, etc.)
– UPS Systems
– Medical Equipment
– Portable Test Equipment
3 Description
The bq76925 host-controlled analog front end (AFE)
is part of a complete pack monitoring, balancing, and
protection system for 3-, 4-, 5-, or 6-series cell Li-Ion
and Li-Polymer batteries. The bq76925 device allows
a Host controller to monitor individual cell voltages,
pack current and temperature easily. The Host may
use this information to determine unsafe or faulty
operating conditions such as overvoltage, under-
voltage, overtemperature, overcurrent, cell imbalance,
state of charge, and state of health conditions.
Cell input voltages are level-shifted, multiplexed,
scaled, and output for measurement by a Host ADC.
A dedicated pin provides a low-drift calibrated
reference voltage to enable accurate measurements.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
bq76925
TSSOP (20)
4.00 mm × 4.00 mm
bq76925
VQFN (24)
6.50 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Simplified Schematic
RBAT
CBAT
CV3P3
PACK+
RIN
RIN
RIN
CIN
CIN
CIN
RIN
CIN
RIN
CIN
RIN
CIN
RIN
CIN
BAT
VCTL
VC6
V3P3
VC5
SCL
VC4
SDA
VC3
VREF
bq76925
VC2
VTB
VC1
VCOUT
VC0
VIOUT
VSS
ALERT
SENSEN
SENSEP
CREF
(Optional)
RTH
CTH
RNTC
COUT
VCC
I2C
ADC Ref
MCU
ADC1 (Temp)
ADC2 (Voltage)
ADC3 (Current)
GPIO (Alert)
GPIO
GPIO
VSS
FET Control
Or
Fault
signaling
RSENSEN
CSENSE
COUT
RSENSEP
RSENSE
PACK-
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.