19-1772; Rev 4; 2/09
Low-Cost, Multichemistry Battery-
Charger Building Block
General Description
Features
o
Input Current Limiting
o
±0.5% Output Voltage Accuracy Using Internal
Reference (0°C to +85°C)
o
Programmable Battery Charge Current >4A
o
Analog Inputs Control Charge Current and
Charge Voltage
o
Monitor Outputs for:
Current Drawn from AC Input Source
Charging Current
AC Adapter Present
o
Up to 18.2V (max) Battery Voltage
o
8V to 28V Input Voltage
o
> 95% Efficiency
o
99.99% (max) Duty Cycle for Low-Dropout
Operation
o
Charges Any Battery Chemistry: Li+, NiCd, NiMH,
Lead Acid, etc.
MAX1772
The MAX1772 is a highly-integrated, multichemistry
battery-charger control IC that simplifies the construc-
tion of accurate and efficient chargers. The MAX1772
uses analog inputs to control charge current and volt-
age and can be programmed by the host or hardwired.
High efficiency is achieved by a buck topology with
synchronous rectification.
Maximum current drawn from the AC adapter is pro-
grammable to avoid overloading the AC adapter when
supplying the load and the battery charger simultane-
ously. This enables the user to reduce the cost of the
AC adapter. The MAX1772 provides outputs that can
be used to monitor the current drawn from the AC
adapter, battery-charging current, and the presence of
an AC adapter.
The MAX1772 can charge two to four lithium-ion (Li+)
series cells, easily providing 4A. When charging, the
MAX1772 automatically transitions from regulating cur-
rent to regulating voltage. It is available in a space-sav-
ing 28-pin QSOP package.
Applications
Notebook and Subnotebook Computers
Personal Digital Assistants
Handheld Terminals
Pin Configuration
TOP VIEW
DCIN 1
LDO 2
CLS 3
REF 4
CCS 5
CCI 6
CCV 7
GND 8
GND 9
ICHG 10
ACIN 11
ACOK 12
REFIN 13
ICTL 14
28 IINP
27 CSSP
26 CSSN
25 BST
Ordering Information
PART
MAX1772EEI
MAX1772EEI+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 QSOP
28 QSOP
+Denotes
lead(Pb)-free/RoHS-compliant package.
MAX1772
24 DHI
23 LX
22 DLOV
21 DLO
20 PGND
19 CSIP
18 CSIN
17 BATT
16 CELLS
15 VCTL
QSOP
________________________________________________________________
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
