SMB347: Programmable Switching Li+ Battery Charger with USB/AC Input, CurrentPath™ Manager, TurboCharge™ Mode*, AICL*, USB On-The-Go and JISC8714/JEITA Support
FEATURES
Efficient battery charging eliminates heat issues
Charge current: up to 2.5A (see SMB346 for 1.25A solution)
Automatic Input Current Limit for universal USB/AC/DC adapter compatibility* (patent granted)
Optional automatic power source detection per USB charging specification 1.2 (except primary detection after DCD timeout)
USB or AC input with automatic input selection and
programmable input current limiting (USB2.0/3.0 compliant)
Up to 750mA charging output from 500mA USB port or 2500mA
from AC adapter using proprietary “TurboCharge™ Mode”
(patent granted)
Input/output CurrentPath™ control allows system operation
with deeply discharged/missing battery – no start-up delay
USB OTG and HDMI/MHL power support (up to 750mA @ +5V)
Float voltage and charge current compensation for JEITA and
JISC 8714 support
3MHz switching allows tiny external components
+4.35 to +6.2V operating input voltage range
+20V input rating (non-operating) with over-voltage protection
Digital programming of all major parameters via I2C interface
º
Pre-charge voltage, float voltage
º
Input/pre-charge/fast charge/term. current
º
Battery temperature limits, safety timers
Comprehensive protection features
º
Status/fault indicator
º
Battery/IC thermal protection
º
Short circuit/UV/OV protection
º
Charge termination safety timers
Tiny CSP packages
INTRODUCTION
The SMB347 is a programmable single-cell lithium-ion/lithium-polymer battery chargers designed for a variety of portable applications. The device provides a simple and efficient way to charge high-capacity Li- Ion batteries and power the system via a USB or AC adapter input. Unlike conventional charging devices, the SMB347’s high-efficiency switch-mode operation eliminates the low charge current and thermal problems of conventional linear solutions. In addition, the switching architecture in conjunction with programmability enables dramatically faster charging from current limited inputs such as USB.
The SMB347 can switch between USB mode and AC Adapter mode and works seamlessly in conjunction with a USB controller. Charge current and input current limits for both USB and AC can be set up to 2.5A. Also the SMB347 can manage two outputs independently: battery charging and system power. This allows immediate system operation even under missing/deeply discharged battery conditions. The SMB347 also supports USB On-the-Go devices by providing the required USB-OTG +5V and up to 750mA power supply using the Li- Ion battery as a source. The USB-ACA standard is also supported.
