R
SR
Adapter
4.5-24V
HOST
bq24725A
Hybrid Power
Boost Charge
Controller
SYS
Battery
Pack
N-FET Driver
N-FET Driver
1S-4S
SMBus
SMBus Controls V & I
with high accuracy
Adapter Detection
Enhanced Safety:
OCP, OVP, FET Short
Integration:
Loop Compensation; Soft-Start
Comparator
R
AC
Product
Folder
Sample &
Buy
Technical
Documents
Tools &
Software
Support &
Community
bq24725A
SLUSAL0A – SEPTEMBER 2011 – REVISED AUGUST 2014
bq24725A 1-4 Cell Li+ Battery SMBus Charge Controller with N-Channel Power MOSFET
Selector and Advanced Circuit Protection
1 Features
3 Description
The bq24725A is a high-efficiency, synchronous
1
•
SMBus Host-Controlled NMOS-NMOS
battery charger, offering low component count for
Synchronous Buck Converter with Programmable
space-constraint, multi-chemistry battery charging
615kHz, 750kHz, and 885kHz Switching
applications.
Frequencies
The
bq24725A
utilizes
two
charge
pumps
to
•
Automatic N-channel MOSFET Selection of
separately
drive
n-channel
MOSFETs
(ACFET,
System Power Source from Adapter or Battery
RBFET and BATFET) for automatic system power
Driven by Internal Charge Pumps
source selection.
•
Enhanced Safety Features for Over Voltage
SMBus controlled input current, charge current, and
Protection, Over Current Protection, Battery,
charge voltage DACs allow for very high regulation
Inductor and MOSFET Short Circuit Protection
accuracies that can be easily programmed by the
•
Programmable Input Current, Charge Voltage,
system power management micro-controller.
Charge Current Limits
The bq24725A uses internal input current register or
–
±0.5% Charge Voltage Accuracy up to 19.2V
external ILIM pin to throttle down PWM modulation to
–
±3% Charge Current Accuracy up to 8.128A
reduce the charge current.
–
±3% Input Current Accuracy up to 8.064A
The bq24725A charges one, two, three or four series
–
±2% 20x Adapter Current or Charge Current
Li+ cells.
Amplifier Output Accuracy
Device Information
(1)
•
Programmable Battery Depletion Threshold, and
PART NUMBER
PACKAGE
BODY SIZE (NOM)
Battery LEARN Function
bq24725A
VQFN (20)
3.50mm x 3.50mm
•
Programmable Adapter Detection and Indicator
(1) For all available packages, see the orderable addendum at
•
Integrated Soft Start
the end of the datasheet.
•
Integrated Loop Compensation
•
Real Time System Control on ILIM pin to Limit
Charge Current
•
AC Adapter Operating Range 4.5V-24V
•
5µA Off-State Battery Discharge Current
•
0.65mA (0.8mA max) Adapter Standby Quiescent
Current
•
20-pin 3.5 x 3.5 mm
2
VQFN Package
2 Applications
•
Portable Notebook Computers, UMPC, Ultra-Thin
Notebook, and Netbook
•
Handheld Terminal
•
Industrial and Medical Equipment
•
Portable Equipment
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.
