UNIVERSAL-CHEMISTRY, LEVEL-2 BATTERY CHARGER HAS INPUT CURRENT LIMITING
SUNNYVALE, CA-November 16, 1999-Maxim Integrated Products introduces the MAX1645, a level-2 compliant battery charger that meets SBS IF Specification v1.0. This high-efficiency battery charger can charge batteries of any chemistry type. It offers a one-chip solution for charging lithium-ion (Li+) cells and contains independent voltage and current regulation circuitry that automatically transitions from constant-current to constant-voltage mode during charge. The MAX1645 can also limit line input current so that it will not exceed a predetermined current drawn from the DC source. The MAX1645 charges one to four series Li+ cells and regulates programmed charge voltages to within ±0.8%.
An advanced synchronous buck topology allows duty cycles up to 99.99%, ensuring low input-to-output voltage differentials while maintaining efficiencies greater than 97%. The MAX1645 has a 5.4V low-dropout linear regulator capable of delivering up to 15mA of current to external loads. The MAX1645 uses an SMBus™ compatible 2-wire interface to receive charging voltage and current commands as well as charger and battery status. A 175sec charge safety timer prevents "runaway charging" if the MAX1645 stops receiving charging voltage/current commands. At power-on reset, the MAX1645 supplies a 128mA "wake-up" charging current to condition deeply discharged cells before applying full charge currents. Charging voltage is programmable from 0 to 18.432V with 11 bits of resolution. Charging current is programmable up to 3A with 6 bits of resolution.
The MAX1645 includes battery thermistor fail-safe protection logic that inhibits charging when the device is operating outside of predetermined temperature limits. The MAX1645 can also signal the host controller when power is applied to the charger or when a battery is installed or removed. It can be connected directly to charge sources from 8V to 28V and can easily charge one to four series Li+ cells.
The MAX1645 is available in a 28-pin QSOP package and is specified for the extended-industrial temperature range (-40°C to +85°C). Prices start from $5.31 (1000-up, FOB USA).
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