MAX1873 Datasheet, PDF (1/14 Pages) Maxim Integrated Products – Simple Current-Limited Switch-Mode Li Charger Controller

19-2099; Rev 0; 7/01
EVALUATION ^{KIT AVAILABLE}
Simple Current-Limited Switch-Mode
Li+ Charger Controller
General Description
The low-cost MAX1873R/S/T provides all functions
needed to simply and efficiently charge 2-, 3-, or 4-
series lithium-ion cells at up to 4A or more. It provides a
regulated charging current and voltage with less than
±0.75% total voltage error at the battery terminals. An
external P-channel MOSFET operates in a step-down
DC-DC configuration to efficiently charge batteries in
low-cost designs.
The MAX1873R/S/T regulates the battery voltage and
charging current using two control loops that work
together to transition smoothly between voltage and
current regulation. An additional control loop limits cur-
rent drawn from the input source so that AC adapter
size and cost can be minimized. An analog voltage out-
put proportional to charging current is also supplied so
that an ADC or microcontroller can monitor charging
current.
The MAX1873 may also be used as an efficient current-
limited source to charge NiCd or NiMH batteries in mul-
tichemistry charger designs. The MAX1873R/S/T is
available in a space-saving 16-pin QSOP package. Use
the evaluation kit (MAX1873EVKIT) to help reduce
design time.
Applications
Notebook Computers
Portable Internet Tablets
2-, 3-, or 4-cell Li+ Battery Pack Chargers
6-, 9-, or 10-cell Ni Battery Pack Chargers
Hand-Held Instruments
Portable Desktop Assistants (PDAs)
Desktop Cradle Chargers
PART
MAX1873REEE
MAX1873SEEE
MAX1873TEEE
Selector Guide
SERIES CELLS TO CHARGE
2-Cell Li+ or 5- or 6-cell Ni Battery
3-Cell Li+ or 7- or 9-cell Ni Battery
4-Cell Li+ 10-cell Ni Battery Packs
Pin Configuration appears at end of data sheet.
Features
o Low-Cost and Simple Circuit
o Charges 2-, 3-, or 4-Series Lithium-Ion Cells
o AC Adapter Input-Current-Limit Loop
o Also Charges Ni-Based Batteries
o Analog Output Monitors Charge Current
o ±0.75% Battery-Regulation Voltage
o 5µA Shutdown Battery Current
o Input Voltage Up to 28V
o 200mV Dropout Voltage/100% Duty Cycle
o Adjustable Charging Current
o 300kHz PWM Oscillator Reduces Noise
o Space-Saving 16-Pin QSOP
o MAX1873 Evaluation Kit Available to Speed
Designs
Ordering Information
PART
MAX1873REEE
MAX1873SEEE
MAX1873TEEE
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
16 QSOP
16 QSOP
VIN 9V TO
28V
(9V MIN
FOR 2-
CELLS)
4V OUT PER
200mV ON RCS
Typical Operating Circuit
SYSTEM
LOAD
VH VL
CSSP
MAX1873
DCIN
CSSN
IOUT
ICHG/EN
EXT
REF
CSB
BATT
CCI
VADJ
CCS
GND
CCV
2- TO 4-CELL
Li+
________________________________________________________________ Maxim Integrated Products 1
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