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