Analog Devices MAX1645B Product Info

• Input Current Limiting
• 175s Charge Safety Timeout
• 128mA Wake-Up Charge
• Charges Any Chemistry Battery: Li+, NiCd, NiMH, Lead Acid, etc.
• Intel SMBus 2-Wire Serial Interface
• Compliant with Level 2 Smart Battery Charger Spec Rev 1.0
• +8V to +28V Input Voltage Range
• Up to 18.4V Battery Voltage
• 11-Bit Battery Voltage Setting
• ±0.8% Output Voltage Accuracy with Internal Reference
• 3A (max) Battery Charge Current
• 6-Bit Charge-Current Setting
• 99.99% (max) Duty Cycle for Low-Dropout Operation
• Load/Source Switchover Drivers
• >97% Efficiency

The MAX1645B is a high-efficiency battery charger capable of charging batteries of any chemistry type. It uses the Intel System Management Bus (SMBus^™) to control voltage and current-charge outputs.

When charging lithium-ion (Li+) batteries, the MAX1645B automatically transitions from regulating current to regulating voltage. The MAX1645B can also limit line input current so as not to exceed a predetermined current drawn from the DC source. A 175s charge safety timer prevents "runaway charging" should the MAX1645B stop receiving charging voltage/current commands.

The MAX1645B employs a next-generation synchronous buck control circuitry that lowers the minimum input-to-output voltage drop by allowing the duty cycle to exceed 99%. The MAX1645B can easily charge one to four series Li+ cells.

Applications

• Notebook Computers
• Personal Digital Assistants
• Point-of-Sale Terminals