Summit Micro Offers Switch-Mode Battery Chargers with Programmable JEITA Support
Summit Microelectronics has expanded its third-generation programmable battery charger integrated circuit (IC) family for single-cell Li-Ion, Li-Polymer, and Li-FePO4 powered systems. According to the company, the SMB328A and SMB328B integrate the largest feature set in the industry, including compatibility with all relevant industry standards: USB 2.0 Specification, USB On-The-Go Supplement, JEITA Safety Guidelines, IEEE1725 Standard, Chinese USB Charging Specification, and others. Both products incorporate what the company calls innovative functionality that allows automatic matching between the ac-dc adaptor’s current capability and the portable device’s charging requirements. High-efficiency operation allows for higher, continuous charging current levels, thereby ensuring battery charging even during high system load conditions.
The SMB328A and SMB328B enable companies to create slim industrial designs with significantly faster charging times; two valuable differentiating factors for smart phones and other portable consumer products.
The devices are based on a 3MHz, switch-mode architecture, with minimal external components, which results in very efficient power delivery and extremely compact solution size. The SMB328A allows for I²C control of parametric and functional performance, while the SMB328B operates in a GPIO-controlled configuration. Summit’s proprietary TurboCharge™ patent-pending technology is incorporated in both devices, enabling highest charging current levels (up to 750mA from 500mA USB source) from current-limited input power sources.
The SMB328A and SMB328B incorporate what the company says is the industry’s widest range of safety features for the battery and the system. Both products adhere to the Japan Electronics and Information Technology Association (JEITA) safety guidelines, by preventing high charging voltage levels during certain low and high temperature ranges. Going a step further, battery pack temperature limits and charging voltage compensation levels are programmable, resulting in optimized operation for a given battery. In addition, the SMB328A and SMB328B support IEEE1725 by including dual redundant protection for input/output current and voltage, chip and battery thermal protection, hardware and software safety timers, battery missing detection and a variety of status and fault registers.
The SMB328A and SMB328B also incorporate an LDO that can provide instant-on power from the input source to critical system components, allowing them to wake-up and perform system functions, even with a deeply discharged (dead), or missing battery. Both products also allow the host to directly measure charge current in real-time, thereby allowing the system to recognize the operating mode it is in, and making necessary adjustments for increasing battery life, monitoring for safety and communicating information to the user. The SMB328A and SMB328B are also capable of supporting USB On-The-Go, by providing 5V and up to 500mA to VBUS, thereby also exceeding the requirements set by the USB OTG Supplemental Specification.
The SMB328A and SMB328B are well suited for a wide range of portable devices such as mobile phones, smartphones, portable media/MP3 players (PMP), portable GPS navigation equipment, portable game consoles, and digital cameras/camcorders (DSC/DCC). The features and integration of the SMB328A and SMB328B make them especially suited for devices that include a USB interface because they allow a tiny, low-cost industry-standard micro USB connector to be the primary data and power/charging interface.
The SMB328A and SMB328B operate with an input range from +3.5 to +6.2V input and safely withstand continuous input over-voltage up to +20V (non-operating), while protecting downstream circuitry. Both products are offered in a tiny 2.2 x 2.0mm, 20-ball, lead-free chip-scale (CSP) package with an operating temperature range of â€“30 to +85°C.
Available now in production quantities, the SMB328A is priced at $1.28 and the SMB328B is priced at $1.23 each in quantities of 10,000 units.