Tiny CSP CurrentPath™ Charger ICs Integrate Programmability, Advanced USB Charging and Safety Features for Cost Sensitive Applications



Summit Microelectronics has introduced its fourth-generation programmable battery charger integrated circuit (IC) family for single-cell Li-Ion, Li-Polymer, and Li-FePO4 battery packs. The SMB231, SMB232 and SMB233 integrate the largest feature set in the industry, including compatibility with all relevant industry standards: USB Battery Charging Revision 1.1, USB 2.0/USB3.0, JEITA Safety, IEEE1725, Chinese USB Charging, and others. All three products incorporate innovative functionality that allows automatic matching between the AC/DC adaptor's current capability and the portable device's charging requirements. Tiny packages and minimum external components allow for small board space and reduced solution cost. Like all Summit's solutions, digital, non-volatile programmability provides design and system flexibility at no additional cost. The SMB231/2/3 family of battery chargers is ideal for a wide range of portable devices such as digital still cameras, mobile phones, digital camcorders, wireless headsets, DECT headsets, portable media/MP3 players (PMP), portable GPS navigation equipment, and portable game consoles/controllers. The SMB231, SMB232 and SMB233 simplify system designs by integrating a robust set of system functions, thereby eliminating a significant number of external components and software requirements. Unlike many traditional charging solutions, these products enable cost-effective and slim industrial designs without compromising performance and safety. Features The SMB231/2/3 products incorporate Summit's CurrentPath™ functionality to allow independent output current paths for the system and the battery, allowing the system to turn on with a missing or deeply-discharged battery. This charging configuration reduces the charge and discharge cycles on the battery, thereby extending its operating life. CurrentPath functionality also allows accurate charge termination, since the devices can detect the current flowing into the battery vs. traditional solutions that can only detect the combined current for battery and system. The devices also include input current limit which allows USB500/100, USB900/150 or AC/DC operation (300mA - 1500mA). An additional option is also available for not limiting input current, thereby supporting high system current levels directly from the input power source, even when the battery is not present. Like all products in Summit's 3rd generation family, the SMB231/2/3 devices provide the means to accomplish true, universal USB charging and to meet the various USB industry standards without the need for additional hardware and software support. The products incorporate Automatic Power Source Detection, adhering to the latest USB Battery Charging Specification 1.1. The SMB231/2/3 devices can also detect non-USB compliant wall adapters, thereby maximizing system reliability and performance. A patented Automatic Input Current Limit capability detects the maximum current capability of the AC/DC adapter and automatically programs the devices' input current limit accordingly. This unique functionality addresses system issues associated with the fact that "USB" AC/DC adapters can vary widely in current rating, while eliminating the need for additional software support or external components. The resulting improved user experience translates into fewer service calls, fewer merchandise returns and increased subscriber revenue for wireless carriers. The SMB231, SMB232 and SMB233 incorporate the industry's widest range of safety features for the battery and the system. All three devices adhere to the Japan Electronics and Information Technology Association (JEITA) safety guidelines, by preventing high charging voltage and/or current levels during certain low and high temperature ranges. Going a step further, battery pack temperature limits, charging voltage and current compensation levels are programmable, resulting in optimized operation for a given battery and system. In addition, the products support IEEE1725 by including dual redundant protection for input/output current and voltage, chip and battery thermal protection, hardware safety timers, battery missing detection and a variety of status and fault registers and indicators. Programmable thermal regulation is also available for preventing system over-heating. The SMB231/2/3 family of products also provides an integrated low-battery voltage detector with programmable voltage thresholds. This function allows the system to receive real-time battery voltage level information and take appropriate actions. "Summit has once again demonstrated its commitment to introduce industry's most innovative battery charging solutions, which solve real system issues and help customers reduce time-to-market and introduce smaller and better portable devices. The SMB231, SMB232 and SMB233 adhere to the latest charging and safety industry standards and integrate many of the system-critical functions," stated George Paparrizos, Summit Marketing Director. "Portable system designs are becoming increasingly complicated and traditional one-size-fits-all solutions do not meet the new performance, system cost, board space and safety requirements." The SMB231, SMB232 and SMB233 operate with an input range from +3.7V to +6.2V input and safely withstand continuous input over-voltage up to +20V (non-operating), while protecting downstream circuitry. Package, Price and Availability The SMB231 and SMB232 are offered in tiny 2.16mm x 1.61mm, 12- and 20-ball, lead-free chip-scale (CSP) packages, while the SMB233 is offered in a small 4mm x 4mm QFN package. All products have an operating temperature range of -30C to +85C. Available now in production quantities, the SMB231 and SMB232 are priced at $0.80 and the SMB233 is priced at $0.88, each in quantities of 10,000 units. Design Software and Programmer for Prototype Development To speed user product development, Summit offers customers the SMB233EV and SMB231EV companion evaluation boards and a graphical user interface (GUI) software so designers can quickly see the features and benefits and design a prototype battery charging solution with the SMB231, SMB232 and SMB233. This is a complete development tool that lets designers easily manipulate the characteristics of their systems. The SMB233EV and SMB231EV design kits include menu-driven Microsoft Windows (R) GUI software to automate programming tasks and also includes all necessary hardware to interface to the USB port of a laptop or PC. Once a user completes design and prototyping, the SMB233EV and SMB231EV automatically generate 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 URL for the SMB231 product is http://www.summitmicro.com/prod_select/summary/SMB231/SMB231.htm