The MAX1645BEEI 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 MAX1645BEEI automatically transitions from regulating current to regulating voltage. The MAX1645BEEI can also limit line input current so as not to exceed a predetermined current drawn from the DC source. A 175sec charge safety timer prevents "runaway charging" should the MAX1645BEEI stop receiving charging voltage/current commands. The MAX1645BEEI 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 MAX1645BEEI can easily charge one to four series Li+ cells. 
Feature
 
 
  
  - Input Current Limiting 
 
  - 175sec 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 
 
 
 
  
Applications
 
 
 
  - Notebook Computers
 
  - PDAs and Other Handheld Devices
 
  - Point-of-Sale Terminals