SUMMIT SMB136

SMB136
Preliminary Information
Programmable Switching Li+ Battery Charger with USB/AC Input, CurrentPath™ Manager,
TurboChargeTM Mode*, Low Battery Recovery*, AICL* and USB On-The-Go Support
FEATURES & APPLICATIONS
INTRODUCTION
• Automatic Input Current Limit for universal USB/AC/DC adapter
compatibility*
• Optional automatic power source detection per latest USB
charging specification 1.0
• USB input with programmable input current limiting (USB2.0
compliant)
• Up to 750mA charging output from 500mA USB port or 1500mA
TM
from AC adapter using proprietary “TurboCharge 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 +6.2V input voltage range
• +18V input tolerance (non-operating)
• High-accuracy float voltage regulation: 1.0%
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• Digital programming of all major parameters via I C 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
The SMB136 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 LiIon batteries via a USB or AC power source. Unlike conventional
charging devices, the SMB136’s high-efficiency switch-mode operation
eliminates the low charge current and thermal problems of
conventional linear solutions. Also the switching architecture in
conjunction with programmability enables dramatically faster charging
– TurboCharge™ mode - from current limited in puts such as USB.
The SMB136 works seamlessly in conjunction with a USB controller.
Also the SMB136 can manage two outputs independently: battery
charging and system power. This allows immediate system operation
even under missing/deeply discharged battery conditions. In the case
of a low battery and insufficient/missing input supply the SMB136 can
run its switching regulator in reverse to support “Low Battery Recovery”
mode (+4.17V @ 500mA) or USB “On the Go” power (+5.0V @
500mA).
Charge control includes input current limit (supporting USB2.0), trickle
charge, pre-charge, constant current/constant voltage, float voltage
and termination/safety settings that are fully programmable via a serial
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I C/SMBus and stored in non-volatile memory making the device truly
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a flexible solution. Fast charge current level can be set via I C (limited
by the input current settings). An Enable (EN) pin is also provided for
suspending charging and/or sleep mode. Built-in reverse-current
blocking prevents inadvertent cell discharge.
The SMB136 also offers a wide variety of features that protect the
battery pack as well as the charger and input circuitry: over-current,
under/over-voltage, safety timers and thermal protection. Accurate
1.0% battery float voltage control ensures complete charging and
improves battery capacity utilization. Status can be monitored via the
serial port for charge state and fault conditions. In addition, the STAT
output can be used to signal charge status. Operating voltage is
specified from +4.35V to +6.2V with +18V non-operating input
tolerance. The SMB136 is available in an ultra-compact CSP-30
package and is rated over the –30C to +85C temperature range.
Applications
Portable Media Players
Smartphones/PDA’s
Digital camcorders/still cameras
Handheld GPS
SYSTEM APPLICATION
Handheld Device
USB
500mA
4.35V-5.5V
VB US D-
USB
D+
Total Sys. Output
>1400mA
"Ideal Diode"
Current
USB-OTG
5.0V @ 500mA
LBR Output
5.0V @ 500mA
Charging Current
up to 1500mA
SMB136
NC GND
USB
System Output
up to 1400mA
USB or AC Input
100/500/700-1400mA
OTG/LBR
750mA
AC/DC
300-1800mA
4.5V-6.0V
I2C (optional)
Li- Ion
System
•
•
•
•
USB
Figure 1 – Using the SMB136 to charge a single cell Li+ battery from USB or AC Adapter power sources
*Patent Pending
© SUMMIT Microelectronics, Inc. 2007 • 757 N. Mary • Sunnyvale CA 94085 • Phone 408 523-1000 • FAX 408 523-1266
http://www.summitmicro.com/
2141 2.0 7/7/2009
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