SMB239 Datasheet, PDF (1/30 Pages) Summit Microelectronics, Inc. – Programmable Linear Battery Charger in 1.3 x 2.1 uCSP

SMB239
Programmable Linear Battery Charger in 1.3 x 2.1 uCSP^TM
FEATURES & APPLICATIONS
INTRODUCTION
• World’s smallest linear charger
• Linear charging for reduced board space
o Up to 525mA 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 (0.5mm pitch)
• High-accuracy output voltage regulation: 1%
• Low reverse leakage current
• Digital programming of all major parameters via I²C
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
o Charge safety timers
o Automatic restart threshold
• Fault/Status indicator
• Wide range of protection features
o Thermal regulation
o Battery pack temperature monitor
o Input/output over-voltage lockout
Applications
• Bluetooth & Stereo Headsets
• Noise Cancellation Headphones
• Wireless Handsets
• MP3 Players
• Wrist PDA/Watches
• Handheld Equipment
The SMB239 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- and medium-capacity Li-Ion or
Li-Polymer batteries via a USB port or an AC port. Unlike conventional
devices, the SMB239’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 SMB239 offers the option to
automatically recharge the battery upon power cycling, only when
battery voltage falls 220/390/550mV below the selectable float voltage.
This allows for a reduced number of charge/discharge cycles, thereby
extending battery life.
The SMB239 offers a wide variety of features that protect the battery
pack as well as the charger and input circuitry: over-current, under-
and 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 junction temperature
approaches approximately 110°C, the SMB239 will start to reduce
charge current to ensure device and system reliability, while charging
the battery cell as fast as possible.
The SMB239 is available in a space-saving, 1.3mm x 2.1mm uCSP^TM
package with lead-free balls and is rated over the –30°C to +85°C
temperature range.
SIMPLIFIED APPLICATIONS DRAWING
4.35V to 6.5V
10V Tolerance
4.7uF
IN ^SMB239 OUT
BATT
I2C Communication
SCL
SDA
THERM
GND STAT
Up to 525mA
Charge Current
Battery
OVLO
4.7uF
1-cell
Li+ Battery
RLIM
RED
LED
Figure 1 – Applications block diagram featuring the SMB239 programmable linear battery charger.
© SUMMIT Microelectronics, Inc. 2005 • 757 N. Mary Avenue • Sunnyvale CA 94085 • Phone [phone] • FAX [phone]
http://www.summitmicro.com/
2129 3.0 2/23/2009
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