MAX1908_05 Datasheet, PDF (1/29 Pages) Maxim Integrated Products – Low-Cost Multichemistry Battery Chargers

19-2764; Rev 4; 7/05
EVAALVUAAILTAIOBNLEKIT
Low-Cost Multichemistry Battery Chargers
General Description
The MAX1908/MAX8724/MAX8765 highly integrated, multi-
chemistry battery-charger control ICs simplify the construc-
tion of accurate and efficient chargers. These devices use
analog inputs to control charge current and voltage, and
can be programmed by the host or hardwired. The
MAX1908/MAX8724/MAX8765 achieve high efficiency
using a buck topology with synchronous rectification.
The MAX1908/MAX8724/MAX8765 feature input current
limiting. This feature reduces battery charge current when
the input current limit is reached to avoid overloading the
AC adapter when supplying the load and the battery
charger simultaneously. The MAX1908/MAX8724/
MAX8765 provide outputs to monitor current drawn from
the AC adapter (DC input source), battery-charging cur-
rent, and the presence of an AC adapter. The MAX1908’s
conditioning charge feature provides 300mA to safely
charge deeply discharged lithium-ion (Li+) battery packs.
The MAX1908 includes a conditioning charge feature
while the MAX8724/MAX8765 do not.
The MAX1908/MAX8724/MAX8765 charge two to four
series Li+ cells, providing more than 5A, and are avail-
able in a space-saving, 28-pin, thin QFN package (5mm
× 5mm). An evaluation kit is available to speed designs.
Applications
Notebook and Subnotebook Computers
Personal Digital Assistants
Handheld Terminals
Minimum Operating Circuit
AC ADAPTER
INPUT
0.01Ω
TO EXTERNAL
LOAD
LDO
FROM HOST μP
CSSP
DCIN
REFIN
CSSN
CELLS
LDO
VCTL
BST
ICTL
DLOV
ACIN
MAX1908
ACOK MAX8724 ^DHI
MAX8765
SHDN
LX
ICHG
DLO
IINP
PGND
CCV
CSIP
CCI
CCS
REF CLS
CSIN
BATT
GND
10μH
0.015Ω
BATT+
Features
♦ ±0.5% Output Voltage Accuracy Using Internal
Reference (0°C to +85°C)
♦ ±4% Accurate Input Current Limiting
♦ ±5% Accurate Charge Current
♦ Analog Inputs Control Charge Current and
Charge Voltage
♦ Outputs for Monitoring
Current Drawn from AC Adapter
Charging Current
AC Adapter Presence
♦ Up to 17.6V Battery-Voltage Set Point
♦ Maximum 28V Input Voltage
♦ > 95% Efficiency
♦ Shutdown Control Input
♦ Charge Any Battery Chemistry
Li+, NiCd, NiMH, Lead Acid, etc.
Ordering Information
PART
MAX1908ETI
MAX8724ETI
MAX8765ETI
TEMP RANGE ^PIN-
PACKAGE
-40°C to +85°C 28 Thin QFN
-40°C to +85°C 28 Thin QFN
-40°C to +85°C 28 Thin QFN
PKG CODE
T2855-6
T2855-6
T2855-6
Pin Configuration
TOP VIEW
DLOV 22
LX 23
BST 24
DHI ²⁵
CSSN 26
CSSP 27
IINP 28
21 20 19 18 17 16 15
MAX1908
MAX8724
MAX8765
14 GND
13 ICTL
12 REFIN
11 ACOK
10 ACIN
9 ICHG
8 SHDN
1 23 4 567
THIN QFN
________________________________________________________________ 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.