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SMB139

TM

Programmable Linear Battery Charger in 1.3 x 2.1 uCSP

FEATURES & APPLICATIONS INTRODUCTION

World’s smallest linear charger

The SMB139 is a programmable single-cell lithium-ion/lithium-polymer battery charger for a variety of portable applications. The device provides a simple way to charge low-capacity Li-Ion or Li-Polymer batteries via a USB port or an AC port. Unlike conventional devices, the SMB139’s very small package and high level of configurability simplify design in a wide range of handheld equipment. Charge control includes qualification, trickle-charge, pre-charge, constant current/constant voltage, and termination/safety settings that are fully programmable via a serial I2C/SMBus making the device truly a flexible solution. Pre-charge, fast charge and termination current levels can be set via I2C commands. The Enable (EN) pin is used for suspending or re-staring the charging process. The SMB139 offers a wide variety of features that protect the battery pack as well as the charger and input circuitry: over-current, under/over-voltage and thermal protection. Ultra-precise, 1% accurate, float voltage control improves battery capacity utilization. Status can be monitored via the serial port for charge state and fault conditions. In addition, one LED driver output can be used to signal charge status. As a protection mechanism, when the

Linear charging for reduced board space

o Up to 210mA charge current * o Stable with small ceramic capacitors

4.35 to 6.5V input voltage range Small 1.3 x 2.1 uCSP

TM

package (0.4mm pitch) High-accuracy output voltage regulation: 1% Low reverse leakage current Digital programming of all major parameters via I

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C interface and lockable non-volatile memory

o Battery voltage set point o Pre-charge, fast charge, termination current o Fast charge voltage threshold o Temperature limits junction temperature approaches approximately 110 o Charge safety timers C, the SMB139 will start to reduce charge current to ensure device and system reliability, while charging the battery cell as fast as possible. The SMB139 is available in a space-saving 1.3mm x 2.1mm uCSP

o

Automatic restart threshold

Fault/Status indicator Wide range of protection features

o Thermal regulation o Input/output over-voltage lockout

Applications

Bluetooth & Stereo Headsets Noise Cancellation Headphones

TM package with lead-free balls and is rated over the –30

MP3 Players

C to +85 C temperature range.

Wrist PDA/Watches Toys Handheld Equipment

SIMPLIFIEDAPPLICATIONSDRAWING

4.35V to 6.5V10V Tolerance IN GNDSTAT

SMB139

2.2 F TRICKLESENSE VDDCAP 1 F Up to 210mACharge CurrentBatteryOVLOI2C Communication(Optional)CHGSET Optional OUT F SCL EN1-cellLi+ BatterySDABATT THERM RLIM REDLED

Figure 1 – Applications block diagram featuring the SMB139 programmable linear battery charger.

* Contact factory for higher current version © SUMMIT Microelectronics, Inc. 2005
• 757 N. Mary Avenue • Sunnyvale CA 94085 • Phone 408 523-1000 • FAX 408 523-1266

http://www.summitmicro.com/

2121 3.0 6/19/2008

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