MAX1679 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Single-Cell Li Battery Charger for Current-Limited Supply

19-1545; Rev 0; 9/99
EVAALVUAAILTAIOBNLEKIT
Single-Cell Li+ Battery Charger
for Current-Limited Supply
General Description
The MAX1679 battery charger for a single lithium-ion (Li+)
cell comes in a space-saving 8-pin µMAX package. This
simple device, in conjunction with a current-limited wall
cube and a PMOS transistor, allows safe and fast charg-
ing of a single Li+ cell.
The MAX1679 initiates charging in one of three ways:
battery insertion, charger power-up, or external manip-
ulation of the THERM pin. Charging terminates when
the average charging current falls to approximately 1%
of the fast-charge current, or when the on-chip counter
times out.
Key safety features include continuous voltage and
temperature monitoring, a programmable charger time-
out, and a 5mA 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 MAX1679 evaluation kit (MAX1679EVKIT) is avail-
able to help reduce design time.
Applications
Single-Cell Li+ Portable Applications
Self-Charging Battery Packs
PDAs
Cell Phones
Cradle Chargers
Pin Configuration
TOP VIEW
IN 1
GATE 2
CHG 3
TSEL 4
MAX1679
µMAX
8 BATT
7 THERM
6 GND
5 ADJ
Features
o Simple Stand-Alone Application Circuit
o Lowest Power Dissipation
o 8-Pin µMAX Package Saves Space
o No Inductor Required
o 0.75% Overall System Accuracy
o Continuous Voltage and Temperature Protection
o Safely Precharges Near-Dead Cells
o Programmable Safety Timeout
o Top-Off Charging to Achieve Full Battery Capacity
o Automatic Power-Down when Power Source is
Removed
PART
MAX1679EUA
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
8 µMAX
Typical Operating Circuit
CURRENT-
LIMITED
VOLTAGE
SOURCE
LED
TIMER
RANGE
SELECT
PFET
IN
GATE
CHG
BATT
MAX1679
TSEL
GND
THERM ADJ
THERMISTOR
BATTERY
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