Linear Technology announces universal 35VIN/35VOUT synchronous step-down battery charger controller

     Linear Technology Corporation introduces the LTC4015, a highly integrated, high-voltage, synchronous step-down battery charger controller that supports a variety of battery chemical compositions and has built-in telemetry. The LTC4015 comes in a 5mm x 7mm QFN package with bare metal pads for excellent thermal performance. Class E and Class I devices are guaranteed to operate in the temperature range -40 °C to 125°C.

     The device efficiently delivers power from a variety of input sources such as AC adapters, solar panels, lithium-ion/polymer, lithium iron phosphate (LiFePO4) or lead-acid battery packs, with system loads up to 35V. The LTC4015 provides advanced system monitoring and management capabilities, including battery coulomb counting and health monitoring. When the master microcontroller is required to access the LTC4015's most advanced features, the I2C port is an option. The main charging function of the product can be adjusted using the pin lap configuration and setting resistors.

     The device provides accurate charge current regulation of ±5% (up to 20A), charge voltage regulation of ±0.5%, and operates in an input voltage range of 4.5V to 35V. Applications include portable medical instruments, military equipment, battery backup applications, industrial handheld devices, industrial lighting, rugged laptops/tablets, and remotely powered communication and telemetry systems.

     The LTC4015 contains an accurate 14-bit analog-to-digital converter (ADC) and a high-resolution Coulomb counter. The ADC continuously monitors a large number of system parameters, including input voltage, input current, battery voltage, and battery current, and reports the battery temperature and battery series resistance (BSR) on command. By monitoring these parameters, the LTC4015 reports on the health of the battery as well as its charging status. All system parameters can be monitored via a two-wire I2C interface, while programmable and masking alerts ensure that only information of interest causes interruptions.

     The LTC4015's on-chip charging mode is optimized for a variety of battery chemical compositions, including lithium-ion/lithium polymer, lithium iron phosphate, and lead-acid batteries. The configuration pins allow the user to choose between several pre-defined charging algorithms for each battery chemical composition, as well as several algorithms whose parameters can be adjusted by I2C. Charge voltage and charge current can be automatically adjusted based on battery temperature to follow JEITA guidelines or custom Settings.