Features: · 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% EfficiencyApplicationNotebook Computers
Point-of-Sale Terminals
Personal Digital AssistantsPinout
SpecificationsDCIN, CVS, CSSP, CSSN, LX to GND....................-0.3V to +30V
CSSP to CSSN, CSIP to CSIN ............................-0.3V to +0.3V
PDS, PDL to GND .................................-0.3V to (VCSSP + 0.3V)
BST to LX.............................................................-0.3V to +6V
DHI to LX...............................................-0.3V to (VBST + 0.3V)
CSIP, CSIN, BATT to GND ..................................-0.3V to +22V
LDO to GND .................-0.3V to (lower of 6V or VDCIN + 0.3V)
DLO to GND .......................................-0.3V to (VDLOV + 0.3V)
REF, DAC, CCV, CCI, CCS, CLS to GND..-0.3V to (VLDO + 0.3V)
VDD, SCL, SDA, INT, DLOV to GND.......................-0.3V to +6V
THM to GND............................................-0.3V to (VDD + 0.3V)
PGND to GND ..................................................-0.3V to +0.3V
LDO Continuous Current...............................................50mA
Continuous Power Dissipation (TA = +70°C)
28-Pin QSOP (derate 10.8mW/°C above +70°C).....860mW
Operating Temperature Range ...................-40°C to +85°C
Storage Temperature................................-60°C to +150°C
Lead Temperature (soldering, 10s) ..........................+300°C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
DescriptionThe MAX1645A are high-efficiency battery chargers capable of charging batteries of any chemistry type. It uses the Intel System Management Bus (SMBusTM) to control voltage and current charge outputs.
When charging lithium-ion (Li+) batteries, the MAX1645 automatically transition from regulating current to regulating voltage. The MAX1645 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 MAX1645 stop receiving charging voltage/ current commands.
The MAX1645A employs a next-generation synchronous buck control circuity that lowers the minimum input-tooutput voltage drop by allowing the duty cycle to exceed 99%. The MAX1645 can easily charge one to four series Li+ cells.
MAX1645A Data Sheet
