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 “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 inadvertent battery discharge
High-efficiency step-down regulator with 2MHz switching
Precision integrated current sensing
+4.35 to +5.5V input voltage range
High-accuracy float voltage regulation: 1.0%
Digital programming of all major parameters via I²C interface
- Pre-charge voltage, float voltage
- Input/pre-charge/fast charge/term. current
-Battery temperature limits, safety timers
Comprehensive protection features
- Status/fault indicator
- Battery/IC thermal protection
- Short circuit/UV/OV protection
- Charge termination safety timers
- Software watchdog timers
Tiny CSP-30 package
SMB137- Programmable Switching Li+ Battery Charger with USB/AC Input, CurrentPath™ Manager, TurboCharge™ Mode*, Low Battery Recovery* and USB On-The-Go Support
INTRODUCTION
The SMB137 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 adapter input. Unlike conventional charging devices, the SMB137'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 SMB137 can switch between USB mode and AC Adapter mode and works seamlessly in conjunction with a USB controller. Also the SMB137 can manage two outputs independently: battery charging and system power. This allows immediate system operation even under missing/deeply discharged battery conditions. Also in the case of a low battery and insufficient/missing input supply the SMB137 can run its switching regulator in reverse to support “Low Battery Recovery” mode or USB “On the Go” power (+5V @ 500mA).
Charge control includes input current limit (supporting USB 2.0), trickle charge, pre-charge, constant current/constant voltage, float voltage and termination/safety settings that are fully programmable via a serial I²C/SMBus and stored in non-volatile memory making the device truly a flexible solution. Fast charge current level can be set via I²C (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 SMB137 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 ensure 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 +5.5V with +16V non-operating input tolerance. The SMB137 is available in a 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
SMB137 System Application
Using the SMB137 to charge a single cell Li+ battery from USB or AC Adapter power sources
NOTE 1 - This is an Advance Information data sheet that describes a Summit product currently in development. It is meant solely as a product description and should not be used as a design tool.
SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained herein reflect representative operating parameters, and may vary depending upon a user’s specific application. While the information in this publication has been carefully checked, SUMMIT Microelectronics, Inc. shall not be liable for any damages arising as a result of any error or omission.
SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation applications where the failure or malfunction of the product can reasonably be expected to cause any failure of either system or to significantly affect their safety or effectiveness. Products are not authorized for use in such applications unless SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT Microelectronics, Inc. is adequately protected under the circumstances.
Revision 1.1 - This document supersedes all previous versions.
