MAX1908_09 Datasheet, PDF (1/30 Pages) Maxim Integrated Products – Low-Cost Multichemistry Battery Chargers

19-2764; Rev 5; 11/09
EVAALVUAAILTAIOBNLEKIT
Low-Cost Multichemistry Battery Chargers
General Description
The MAX1908/MAX8724/MAX8765/MAX8765A highly
integrated, multichemistry battery-charger control ICs
simplify the construction of accurate and efficient charg-
ers. These devices use analog inputs to control charge
current and voltage, and can be programmed by the host
or hardwired. The MAX1908/MAX8724/MAX8765/
MAX8765A achieve high efficiency using a buck topology
with synchronous rectification.
The MAX1908/MAX8724/MAX8765/MAX8765A 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/MAX8765A provide out-
puts to monitor current drawn from the AC adapter (DC
input source), battery-charging current, and the pres-
ence 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/MAX8765A do not.
The MAX1908/MAX8724/MAX8765/MAX8765A charge two
to four series Li+ cells, providing more than 5A, and are
available 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 MAX8765A ^LX
ICHG
DLO
IINP
PGND
CCV
CSIP
CCI
CCS
REF CLS
CSIN
BATT
GND
10µH
0.015Ω
BATT+
Features
o ±0.5% Output Voltage Accuracy Using Internal
Reference (±0.4% for MAX8765A, 2-/3-Cell Only)
o ±4% Accurate Input Current Limiting
o ±5% Accurate Charge Current
o Analog Inputs Control Charge Current and
Charge Voltage
o Outputs for Monitoring
Current Drawn from AC Adapter
Charging Current
AC Adapter Presence
o Up to 17.6V Battery-Voltage Set Point
o Maximum 28V Input Voltage
o > 95% Efficiency
o Shutdown Control Input
o Charge Any Battery Chemistry
Li+, NiCd, NiMH, Lead Acid, etc.
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX1908ETI+
-40°C to +85°C 28 Thin QFN-EP*
MAX8724ETI+
-40°C to +85°C 28 Thin QFN-EP*
MAX8765ETI+
-40°C to +85°C 28 Thin QFN-EP*
MAX8765AETI+
-40°C to +85°C 28 Thin QFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
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
MAX8765A
1 23 4 567
14 GND
13 ICTL
12 REFIN
11 ACOK
10 ACIN
9 ICHG
8 SHDN
THIN QFN
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.