SLUSAL0C
September 2011 – January 2020
BQ24725A
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
Pin Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Timing Characteristics
6.7
Typical Characteristics
7
Parameter Measurement Information
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
SMBus Interface
8.4
Device Functional Modes
8.4.1
Adapter Detect and ACOK Output
8.4.2
Adapter Over Voltage (ACOVP)
8.4.3
System Power Selection
8.4.4
Battery LEARN Cycle
8.4.5
Enable and Disable Charging
8.4.6
Automatic Internal Soft-Start Charger Current
8.4.7
High Accuracy Current Sense Amplifier
8.4.8
Charge Timeout
8.4.9
Converter Operation
8.4.10
Continuous Conduction Mode (CCM)
8.4.11
Discontinuous Conduction Mode (DCM)
8.4.12
Input Over Current Protection (ACOC)
8.4.13
Charge Over Current Protection (CHGOCP)
8.4.14
Battery Over Voltage Protection (BATOVP)
8.4.15
Battery Shorted to Ground (BATLOWV)
8.4.16
Thermal Shutdown Protection (TSHUT)
8.4.17
EMI Switching Frequency Adjust
8.4.18
Inductor Short, MOSFET Short Protection
8.5
Register Maps
8.5.1
Battery-Charger Commands
8.5.2
Setting Charger Options
Table 3.
Charge Options Register (0x12H)
8.5.3
Setting the Charge Current
Table 4.
Charge Current Register (0x14H), Using 10mΩ Sense Resistor
8.5.4
Setting the Charge Voltage
Table 5.
Charge Voltage Register (0x15H)
8.5.5
Setting Input Current
Table 6.
Input Current Register (0x3FH), Using 10mΩ Sense Resistor
9
Application and Implementation
9.1
Application Information
9.2
Typical Applications
9.2.1
Typical System with Two NMOS Selector
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.2.1
Negative Output Voltage Protection
9.2.1.2.2
Reverse Input Voltage Protection
9.2.1.2.3
Reduce Battery Quiescent Current
9.2.1.2.4
Inductor Selection
9.2.1.2.5
Input Capacitor
9.2.1.2.6
Output Capacitor
9.2.1.2.7
Power MOSFETs Selection
9.2.1.2.8
Input Filter Design
9.2.1.2.9
BQ24725A Design Guideline
9.2.1.3
Application Curves
9.2.2
Simplified System without Power Path
9.2.2.1
Design Requirements
9.2.2.2
Detailed Design Procedure
9.2.2.3
Application Curves
9.3
System Examples
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
12
Device and Documentation Support
12.1
Third-Party Products Disclaimer
12.2
Receiving Notification of Documentation Updates
12.3
Support Resources
12.4
Trademarks
12.5
Electrostatic Discharge Caution
12.6
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RGR|20
MPQF239A
Thermal pad, mechanical data (Package|Pins)
RGR|20
QFND242E
Orderable Information
slusal0c_oa
slusal0c_pm
1
Features
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 LEARN 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 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