Summit has expanded its third-generation programmable battery charger IC (integrated circuit) family with the introduction of the SMB329. Based on the highly-integrated SMB339 family, the IC integrates additional features, such as ‘instant-on' and real-time charge current monitoring. The device provides 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. The IC'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. The high-efficiency switch-mode operation and TurboCharge mode enable shorter charging times, while reducing thermal dissipation and wasted power. The IC supports all relevant interfaces such as USB2.0, USB OTG and USB charging, and conforms to safety standards like the IEEE1725 and JICS8714 without the need for additional hardware and software support. This support has resulted in reduced development time and cost associated with system compliancy efforts. The IC supports the industry's environmental and green efforts by enabling universal USB charging, eliminating electronic waste and reducing energy usage.
The IC is based on a 3MHz, switch-mode architecture, with minimal external components that allows efficient power delivery and 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. The TurboCharge technology enables high charge current from relatively low-power sources; for example, up to 750mA output is obtained from 500mA USB source.
The device allows a host to directly measure charge current in real-time, allowing the system to recognise the operating mode it is in. The device can make necessary adjustments for increasing the battery life, monitoring for safety and communicating information to the user. The device's Power Source Detection and Automatic Input Current Limit can ensure that the charge current is safely and dynamically optimised regardless of power source capability. The device provides good design flexibility and integration to enable compact designs.
The IC supports USB OTG (on-the-go) with integrated VBUS power, without needing additional components or cost. The device's step-down converter, which 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, thus exceeding the USB OTG supplement specification requirements. The USB OTG allows two portable USB devices to connect to and/or power each other without the presence of a host PC. This creates more opportunities for mobile connectivity, such as exchange of media files between portable devices or charging a Bluetooth headset from a mobile phone. The device supports the industry's complete set of safety features including input/output current limits, input and battery over-voltage protection, battery and chip thermal protection, charge safety and watchdog timers, trickle charging and status/fault monitors. The chip's parametric programmability allows the implementation of sophisticated embedded charging algorithms, further increasing system performance and reliability.
The IC operates with an input range from 3.5 to 6.2V input and safely withstands continuous input over-voltage up to +18V, while protecting downstream circuitry. The device is offered in a small 2.3x2.0mm, 20-ball, lead-free CSP (chip-scale package) and in a 4x4 QFN-24 package with an operating temperature range of -30 to +85°C. The IC is suitable for portable devices, such as mobile phones, smartphones/PDAs, PMP (portable media/MP3 players), portable GPS navigation, portable game consoles and DSC/DCC (digital cameras/camcorders). The features and integration of the IC make it suitable for portable devices that require compliancy with USB battery charging specifications, utilise higher-capacity batteries and feature compact industrial designs.
The company offers the SMB329EV companion evaluation board and a GUI (graphical user interface) software so that designers can quickly see the features and benefits and design a prototype battery charging solution with the SMB329. The SMB329EV design kit includes menu-driven Microsoft Windows GUI software to automate programming tasks. It also includes all the necessary hardware required to interface to the USB port of a laptop or PC. Once a user completes design and prototyping, the kit automatically generates a Hex data file that can be transmitted to the company for review and approval. The company then assigns a customer identification code to the Hex file and programs the customer's production devices prior to final electrical test operations. This can ensure that the device will operate properly in the end application.
