Rainbow Electronics MAX8724 - Manual

General Description
The MAX1908/MAX8724 highly integrated, multichemistry
battery-charger control ICs simplify the construction of
accurate and efficient chargers. These devices use ana-
log inputs to control charge current and voltage, and can
be programmed by the host or hardwired. The MAX1908/
MAX8724 achieve high efficiency using a buck topology
with synchronous rectification.
The MAX1908/MAX8724 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 provide outputs
to monitor current drawn from the AC adapter (DC input
source), battery-charging current, and the presence of
an AC adapter. The MAX1908’s conditioning charge fea-
ture provides 300mA to safely charge deeply discharged
lithium-ion (Li+) battery packs.
The MAX1908 includes a conditioning charge feature
while the MAX8724 does not.
The MAX1908/MAX8724 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
Hand-Held Terminals
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
♦ Charges Any Battery Chemistry
Li+, NiCd, NiMH, Lead Acid, etc.
MAX1908/MAX8724
Low-Cost Multichemistry Battery Chargers
________________________________________________________________ Maxim Integrated Products 1
28 27 26 25 24 23 22
IINP CSSP CSSN DHI BST LX DLOV
8 9 10 11 12 13 14
SHDN ICHG ACIN ACOK REFIN
ICTL GND
15
16
17
18
19
20
21
VCTL
BATT
CELLS
CSIN
CSIP
PGND
DLO
7
6
5
4
3
2
1
CCV
CCI
CCS
REF
CLS
LDO
DCIN
MAX1908
MAX8724
THIN QFN
TOP VIEW
Pin Configuration
Ordering Information
MAX1908
MAX8724
AC ADAPTER
INPUT
TO EXTERNAL
LOAD
LDO
FROM HOST µP
10µH
0.015Ω
BATT+
DCIN
REFIN
VCTL
ICTL
ACIN
ACOK
SHDN
ICHG
IINP
CCV
CCI
CCS
CELLS
LDO
BST
DLOV
DHI
LX
DLO
PGND
CSIP
CSIN
BATT
REF CLS GND
CSSP CSSN
0.01Ω
Minimum Operating Circuit
19-2764; Rev 1; 1/04
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.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX1908ETI -40°C to +85°C 28 Thin QFN
MAX8724ETI -40°C to +85°C 28 Thin QFN