Integrated battery charger has optional power point tracking
An integrated, high voltage multi-chemistry synchronous monolithic step-down battery charger and PowerPath manager with onboard telemetry functions and optional maximum power point tracking (MPPT) has been announced by Analog Devices. The Power by Linear LTC4162 is 3.2A, 35VIN/35VOUT synchronous monolithic multi-chemistry PowerPath manager/charger with digital I2C telemetry and MPPT operation.
The LTC4162 transfers power from a variety of input sources, such as wall adapters, backplanes and solar panels, to charge a Li-Ion/polymer, LiFePO4 or lead-acid battery stack and provide power to a system load up to 35V. The device provides advanced system monitoring and PowerPath management, plus battery health monitoring. A host microcontroller is required to access the most advanced features of the LTC4162, although the use of the I2C port is optional, says ADI.
The main charging features of the product can be adjusted using pin-strap configurations and programming resistors. The device offers precision ± five per cent charge current regulation up to 3.2A, ±0.75 per cent charge voltage regulation and operates over a 4.5 to 35V input voltage range. Applications include portable medical instruments, USB power delivery (one to five devices), military equipment, industrial handhelds and ruggedised notebook or tablet computers.
The LTC4162 contains a 16-bit analogue-to-digital converter (ADC) that continuously monitors system parameters on command, including input voltage, input current, battery voltage, battery current, output voltage, battery temperature, die temperature and battery series resistance (BSR). All system parameters can be monitored via a two-wire I2C interface, while programmable and maskable alerts ensure that only the information of interest causes an interrupt.
The active maximum power point tracking algorithm globally sweeps an input under-voltage control loop and selects an operating point to maximise power extraction from solar panels and other resistive sources. The LTC4162’s PowerPath topology decouples the output voltage from the battery, thereby allowing a portable product to start-up instantly when a charging source is applied under very low battery voltage conditions.
The LTC4162’s on-board charging profiles are optimised for each of a variety of battery chemistries, including Li-Ion/polymer, LiFePO4 and lead acid. Both charge voltage and charge current can be automatically adjusted based on battery temperature to comply with JEITA guidelines, or custom settings.
The LTC4162 is housed in a 28-lead, 4.0 x 5.0mm QFN package with an exposed metal pad for excellent thermal performance. E- and I-grade devices are guaranteed for operation from –40 to +125 degree C.