1FEATURES
2• SMBus Host-Controlled NMOS-NMOS
Synchronous Buck Converter with
Programmable 615kHz, 750kHz, and 885kHz
Switching Frequencies
• Automatic N-channel MOSFET Selection of
System Power Source from Adapter or Battery
Driven by Internal Charge Pumps
• Enhanced Safety Features for Over Voltage
Protection, Over Current Protection, Battery,
Inductor and MOSFET Short Circuit Protection
• Programmable Input Current, Charge Voltage,
Charge Current Limits
– ±0.5% Charge Voltage Accuracy up to 19.2V
– ±3% Charge Current Accuracy up to 8.128A
– ±3% Input Current Accuracy up to 8.064A
– ±2% 20x Adapter Current or Charge Current
Amplifier Output Accuracy
• Programmable Battery Depletion Threshold,
and Battery LERAN Function
• Programmable Adapter Detection and
Indicator
• Integrated Soft Start
• Integrated Loop Compensation
• Real Time System Control on ILIM pin to Limit
Charge Current
• AC Adapter Operating Range 9V-24V
• 5μA Off-State Battery Discharge Current
• 20-pin 3.5 x 3.5 mm2 QFN Package

APPLICATIONS
• Portable Notebook Computers, UMPC, Ultra-
Thin Notebook, and Netbook
• Personal Digital Assistant
• Handheld Terminal
• Industrial and Medical Equipment
• Portable Equipment

DESCRIPTION
The bq24725 is a high-efficiency, synchronous
battery charger, offering low component count for
space-constraint, multi-chemistry battery charging
applications.
The bq24725 uses two charge pumps to separately
drive n-channel MOSFETs (ACFET, RBFET and
BATFET) for automatic system power source
selection.
SMBus controlled input current, charge current, and
charge voltage DACs allow for high regulation
accuracies that can be programmed by the system
power management micro-controller.
The bq24725 uses internal input current register or
external ILIM pin to throttle down PWM modulation to
reduce the charge current.
The bq24725 charges two, three or four series Li+
cells, and is available in a 20-pin, 3.5 x 3.5 mm2 QFN
package.