MAX1879 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – Simple, Efficient, 1-Cell Li+ Pulse Charger

19-2061;
Rev
0; 5/01
EVALUATION
KIT
AVAILABLE
Simple, Efficient, 1-Cell Li+ Pulse Charger
General Description
The MAX1879 single-cell lithium-ion (Li+) battery charger
utilizes an efficient pulse-charging architecture to minimize
power dissipation in portable devices. This architecture
combines the efficiency of switch-mode chargers with the
simplicity and low cost of linear chargers. This simple
device, in conjunction with a current-limited wall cube and
a PMOS transistor, allows safe and fast charging of a sin-
gle Li+ cell.
The MAX1879 initiates charging in one of three ways: bat-
tery insertion, charger power-up, or toggling the THERM
pin. Key safety features include continuous voltage and
temperature monitoring, a preset charger time-out, and an
8mA precharge current mode to charge near-dead cells.
Automatic detection of input power removal shuts down
the device, minimizing current drain from the battery. An
overall system accuracy of 0.75% ensures that the cell
capacity is fully utilized without cycle life degradation.
The MAX1879 is offered in a space-saving 8-pin µMAX
package. An evaluation kit (MAX1879EVKIT) is available
to help reduce design time.
Applications
Single-Cell Li+ Powered Portables
Self-Charging Battery Packs
PDAs
Cell Phones
Cradle Chargers
Features
o Simple Design Minimizes Heat
o Low Component Count, No Inductor
o Battery-Full Indicator
o 0.75% Accurate Battery Regulation
o 1.5µA (max) Battery Current Drain with Wall Cube
Removed
o Restart Charging at 4.0V
o Continuous Overvoltage and Overtemperature
Protection
o Safely Precharges Near-Dead Cells
o Automatic Power-Down when Power Source is
Removed
o Charges 1 Cell from as Low as 4.5V
o Pin-Compatible Upgrade to MAX1679
PART
MAX1879EUA
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
8-µMAX
TOP VIEW
Pin Configuration
IN 1
GATE 2
CHG 3
TSEL 4
MAX1879
8 BATT
7 THERM
6 GND
5 ADJ
µMAX
Typical Operating Circuit
CURRENT-
LIMITED
AC WALL
ADAPTER
LED
PULSE WIDTH
SELECT INPUT
IN
GATE
CHG
BATT
MAX1879
TSEL
GND
THERM
ADJ
THERMISTOR
1-CELL
Li+
BATTERY
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.