Summit Micro Expands Family Of Tiny, Programmable Switch-Mode Battery Chargers
Summit Microelectronics has expanded its third-generation programmable battery charger integrated circuit (IC) family with the introduction of the SMB329. Based on the SMB339 family, the SMB329 integrates additional features, such as "instant-on", even with a dead battery, and real-time charge current monitoring. Like its predecessors, the SMB329’s parameters are programmable in non-volatile memory for power-up configuration, and in volatile memory for in-system adjustments via the I²C host interface. In addition, high-efficiency switch-mode operation and TurboCharge mode allow for thirty to 50% shorter charging times, while reducing thermal dissipation and wasted power by 80%.
The SMB329 supports all relevant interface (USB2.0, USB OTG, USB charging, etc.) and safety (IEEE1725, JICS8714, etc.) standards, resulting in reduced development time and cost associated with system compliancy efforts. Additionally, the SMB329 supports the industry’s environmental and Green efforts by enabling universal USB charging, eliminating electronic waste while dramatically reducing energy usage.
The SMB329 is based on a 3MHz, switch-mode architecture, with minimal external components, which allows for very efficient power delivery and extremely compact solution size. High-efficiency operation enables fast charging due to higher output/charge currents, while reduced thermal dissipation improves user comfort and system reliability. Furthermore, Summit’s proprietary TurboCharge patent-pending technology enables high charge current, even from relatively low-power sources (example: up to 750mA output from 500mA USB source). As consumer devices continue to employ larger batteries, the SMB329 reduces charge time for consumer convenience.
The SMB329 provides integrated instant-on operation, improving consumer convenience without the cost and size penalty of alternate implementations. The SMB329 also allows 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 SMB329’s Power Source Detection and Automatic Input Current Limit (patent pending) ensure that the charge current is safely and dynamically optimized regardless of power source capability (USB or AC/DC). The resulting improved user experience translates into fewer service calls, fewer merchandise returns and increased subscriber revenue for wireless carriers.
In addition to USB battery charging, the SMB329 (like all SMB339 family chargers) supports USB On-the-Go (OTG) with integrated VBUS power without additional components or cost. The SMB329’s step-down converter, that normally operates in "forward mode" to charge the battery, can operate in reverse to boost the battery voltage to +5V for USB-OTG and deliver up to 500mA, exceeding the USB OTG Supplement Specification requirements. USB-OTG allows two portable USB devices (phones, digital cameras, etc.) to connect to and/or power each other without the presence of a host PC. This creates virtually unlimited opportunities for mobile connectivity, such as exchange of media files between portable devices or charging a Bluetooth headset from a mobile phone.
The SMB329 is well suited for any portable device, such as mobile phones, smartphones/PDAs, portable media/MP3 players (PMP), portable GPS navigation, portable game consoles, and digital cameras/camcorders (DSC/DCC). The features and integration of the SMB329 make it especially suited for portable devices that require compliancy with USB battery charging specifications, utilize higher-capacity batteries and feature very compact industrial designs.
The SMB329 operates with an input range from +3.5 to +6.2V input and safely withstands continuous input over-voltage up to +18V (non-operating), while protecting downstream circuitry. The SMB329 is offered in a tiny 2.3 x 2.0mm, 20-ball, lead-free chip-scale (CSP) and in a 4 x 4 QFN-24 package with an operating temperature range of -30 to +85°C.
Available now in production quantities, the SMB329 is priced at $1.15 each in quantities of 10,000 units.
