INTRODUCTION
The SMB137B is a programmable single-cell lithium-ion/lithium polymer battery charger designed for a variety of portable applications. The device provides a simple and efficient way to charge high-capacity Li-Ion batteries via a USB or AC adapter input. Unlike conventional charging devices, the SMB137B’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– TurboCharge™ mode - from current limited in puts such as USB.

FEATURES & APPLICATIONS
• Automatic Input Current Limit for universal USB/AC/DC adapter compatibility*
• Optional automatic power source detection per latest USB charging specification 1.0
• USB or AC input with automatic input selection and programmable input current limiting (USB2.0 compliant)
• Up to 750mA charging output from 500mA USB port or 1500mA from AC adapter using proprietary “TurboChargeTM Mode”
• Input/output CurrentPath™ control allows system operation with deeply discharged/missing battery – no start-up delay
• “Low Battery Recovery” mode for >500mA startup from 100mA USB port with deeply discharged cells – no start-up delay
• USB On-the-Go (OTG) power support (up to 500mA @ +5V)
• Reverse current blocking prevents battery discharge
• High-efficiency step-down regulator with 3MHz switching
• +4.35 to +6.0V input voltage range
• +18V input tolerance (non-operating)
• High-accuracy float voltage regulation: 1.0%
• 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
o Software watchdog timers
• Tiny CSP-30 package