A battery charging voltage range of 1.2V to 60V, programmable via a resistor with a charging voltage accuracy of ±0.5%, and built-in charge termination make the LTC4079 suitable for numerous battery chemistries, including Li-Ion, nickel, and lead-acid. The charging current is adjustable from 10mA to 250mA using an external resistor, and unlike other chargers on the market, the device maintains its high accuracy even at low charge levels. Common applications include embedded systems in automotive and industrial applications, backup battery charging, energy harvesting, and thin-film battery products.
The LTC4079's input voltage regulation function can regulate the IN pin to a constant voltage or a constant differential voltage higher than the battery voltage when charging from a current-limited source such as a low-charge battery or a solar panel. These functions can also be used to prevent the input voltage from falling below the undervoltage lockout (UVLO) or to maintain the input source voltage at its maximum power transfer point. The charging current is reduced when the input voltage drops below the programmed threshold. This regulation mechanism allows the charging current to be selected based on the battery's requirements and the maximum power available from the input source, letting the LTC4079 take over if the input source is unable to supply the full programmed charging current.
The LTC4079's thermal regulation ensures a maximum charging current up to the specified limit without risk of overheating. The charging process can be terminated using C/10 or the built-in adjustable timer. Other features include multi-temperature ready charging via an NTC thermistor, faulty battery detection, automatic recharging with standby feedback sampling for negligible battery drain, and an open-drain CHRG pin status output.
The LTC4079 is supplied in a low-profile (0.75mm), 10-pin, 3mm x 3mm DFN package with a metallized back panel for excellent thermal performance. The device is guaranteed to operate between -40°C and 125°C for E and I grades.
