Maxim Integrated Products introduced the MAX8730, a highly integrated, accurate, and low-cost battery-charger. The IC charges three to four Lithium-ion cells in series at charge currents greater than 3.5 A. Analog inputs control input current limit, charge current, and voltage. An integrated 3.3-V LDO supplies over 20 mA current to any external circuitry or ICs, such as a keyboard controller. Three monitoring outputs simplify design, and save external component cost and board space. Two analog outputs are available for charge current and input current; a digital output is used to detect AC-adapter presence.
The MAX8730 provides 0.5% accurate battery-voltage regulation, which increases battery capacity and minimizes charging time. The device can be hardwired or controlled by a microprocessor to set the charging current or voltage. Based on the presence or absence of an AC adapter, the charger uses two p-channel MOSFETs to automatically select the appropriate source for powering the system.
Housed in a 5- by 5-mm, 28-pin QFN, the MAX8730 is specified for the extended industrial temperature range (-40°C to +85°C). Prices start at $5.04 in lots of 1000. A data sheet is available at www.maxim-ic.com/MAX8730.