Battery Charger IC - SMB139 - Summit Microelectronics

Summit Microelectronics introduced the SMB139 single-cell, Li-Ion and Li-Polymer linear battery charger, new member of company’s  Programmable Battery Charger integrated circuits (ICs). The SMB139 battery charger IC comes in tiny size of package (1.3mm x 2.1mm), makes it ideal for portable applications.  The new battery charger chip also integrates many protection features to ensure high level of safety. The device’s battery charging profile can be configured to adapt easily to new system designs and battery types.

The SMB139 battery charger IC offers flexible programmability with the I2C interface allows convenient parametric and functional control and provides unlimited design flexibility, both in-system and during the development stage. Unlike other linear chargers offered in packages with a limited number of pins, the SMB139’s chip-scale package allows the integration of a higher number of features, including critical charging protection functionality. Overall, the SMB139 enables new standards for performance, mobility and safety in portable consumer electronics.

Summit SMB139 Battery Charger IC

The new battery charger chip comprises a highly integrated, 210mA linear charging solution that utilizes a fully programmable algorithm for single-cell Li-Ion and Li-Polymer cells. All charging parameters - pre-charge/fast-charge/charge termination current, battery temperature/timer safety limits, cell float/pre-charge voltage, are configurable via the I2C/SMBus interface.

The SMB139 battery charger IC can be programmed either dynamically (real-time using volatile registers), by a microcontroller and software via the I2C/SMBus port, or statically (pre-programmed using non-volatile registers). If the static programming mode is used there is no need for software to access the I2C/SMBus interface and the SMB139 battery charger functions independently as a customized, but parametrically fixed solution. Static configurability allows the same product to be used in different system designs and/or with different battery types and technologies, resulting in significantly lower qualification/inventory costs and sourcing risks.

Summit SMB139 Battery Charger Block Diagram

The new battery charger IC operates from a +4.35V to +6.5V input making it ideally suited for either USB or AC adapter power sources. However, for applications where the AC adapter may be poorly regulated and/or an aftermarket or counterfeit product is used, the SMB139 battery charger will tolerate +10V inputs without damage. Ensuring long battery life when not connected to a DC power source, the reverse leakage current is less than 2microA. In addition, when the I2C/SMBus port is not utilized for charge control/monitoring, the SMB139 battery charger chip provides a CHGSET control pin for real-time, two-level charge current configuration, as well as a STATUS output to drive an LED for indicating charge status and fault conditions.

The SMB139 IC integrates input/output over-voltage, short-circuit and thermal protection circuits. A variety of fault and status registers are also available for real-time monitoring charging and system operation. The SMB139 battery charger IC also protects the battery pack with a programmable battery temperature monitor and charge safety timers to prevent dangerous charging conditions. Furthermore, to protect deeply discharged cells, the SMB139 battery charger chip has a 3mA trickle charge mode below 2.0V. This mode allows safe, controlled recovery of the deeply discharged cell until it can accept normal charging currents. All these protection features allow designs to meet strict industry safety standards without the need for additional external components and cost.

The SMB139 battery charger IC is well suited for a wide range of space-constrained handheld consumer devices such as Bluetooth headsets, stereo headsets, flash-based portable music players, noise-cancellation headphones, robotic toys and wrist watches/PDAs. In particular, it is the ideal battery charging solution for applications that utilize small-capacity Li+ batteries and/or use a single USB connector to provide both data and power.

Design Software and Programmer for Prototype Development
To speed user product development, Summit offers customers the SMB139EV companion evaluation board and a graphical user interface (GUI) software so designers can quickly see the features and benefits and design a prototype battery charger with the SMB139 battery charger IC. This is a complete development tool that lets designers easily manipulate the characteristics of their systems. The SMB139EV design kit includes menu-driven Microsoft Windows (R) GUI software to automate programming tasks and also includes all necessary hardware to interface to the parallel or USB port of a laptop or PC.

Once a user completes design and prototyping, the SMB139EV automatically generates a HEX data file that can be transmitted to Summit for review and approval. Summit then assigns a unique customer identification code to the HEX file and programs the customer's production devices prior to final electrical test operations. This ensures that the device will operate properly in the end application. The design kit software can be downloaded today from Summit's website.

The SMB139 battery charger chip  has an operating temperature range of -30 degrees C to +85 degrees C and is available in the 1.3mm x 2.1mm 15-ball chip-scale (CSP) package. The battery charger IC is   available at $0.85 each in 10K qty

More info:  Summit SMB139 Battery Charger IC