Datasheet

19-4410; Rev 5; 9/11
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
MAX8903A–E/G/H/J/N/Y
2A 1-Cell Li+ DC-DC Chargers
for USB and Adapter Power
EVALUATION KIT AVAILABLE
General Description
The MAX8903A–MAX8903E/MAX8903G/MAX8903H/
MAX8903J/MAX8903N/MAX8903Y are integrated 1-cell
Li+ chargers and Smart Power Selectors™ with dual
(AC adapter and USB) power inputs. The switch mode
charger uses a high switching frequency to eliminate
heat and allow tiny external components. It can operate
with either separate inputs for USB and AC adapter
power, or from a single input that accepts both. All
power switches for charging and switching the load
between battery and external power are included on-
chip. No external MOSFETs, blocking diodes, or cur-
rent-sense resistors are required.
The MAX8903_ features optimized smart power control
to make the best use of limited USB or adapter power.
Battery charge current and SYS output current limit are
independently set. Power not used by the system
charges the battery. Charge current and SYS output cur-
rent limit can be set up to 2A while USB input current can
be set to 100mA or 500mA. Automatic input selection
switches the system from battery to external power. The
DC input operates from 4.15V to 16V with up to 20V pro-
tection, while the USB input has a range of 4.1V to 6.3V
with up to 8V protection.
The MAX8903_ internally blocks current from the bat-
tery and system back to the DC and USB inputs when
no input supply is present. Other features include pre-
qual charging and timer, fast charge timer, overvoltage
protection, charge status and fault outputs, power-OK
monitors, and a battery thermistor monitor. In addition,
on-chip thermal limiting reduces battery charge rate
and AC adapter current to prevent charger overheat-
ing. The MAX8903_ is available in a 4mm x 4mm, 28-pin
thin QFN package.
The various versions of the MAX8903_ allow for design
flexibility to choose key parameters such as system
regulation voltage, battery prequalification threshold,
and battery regulation voltage. The MAX8903B/
MAX8903E/MAX8903G also includes power-enable on
battery detection. See the
Selector Guide
section for
complete details.
Applications
Features
o Efficient DC-DC Converter Eliminates Heat
o 4MHz Switching for Tiny External Components
o Instant On—Works with No/Low Battery
o Dual Current-Limiting Inputs—AC Adapter or USB
Automatic Adapter/USB/Battery Switchover to
Support Load Transients
50m System-to-Battery Switch
Supports USB Spec
o Thermistor Monitor
o Integrated Current-Sense Resistor
o No External MOSFETs or Diodes
o 4.1V to 16V Input Operating Voltage Range
Pin Configuration appears at end of data sheet.
Selector Guide appears at end of data sheet.
CHARGE
AND
SYS LOAD
SWITCH
DC
SYS
BAT
AC
ADAPTER
OR USB
SYSTEM
LOAD
BATTERY
GND
USB
USB
CHARGE
CURRENT
LOAD
CURRENT
LX
CS
PWM
STEP-DOWN
MAX8903_
Typical Operating Circuit
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
PDAs, Palmtops, and
Wireless Handhelds
Personal Navigation
Devices
Smart Cell Phones
Portable Multimedia
Players
Mobile Internet Devices
Ultra Mobile PCs
Ordering Information
+
Denotes a lead(Pb)-free/RoHS-compliant package.
*
EP = Exposed pad.
T = Tape and reel.
PART TEMP RANGE PIN-PACKAGE
MAX8903AETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903BETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903CETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903DETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903EETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903GETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903HETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903JETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903NETI+T
-40°C to +85°C
28 Thin QFN-EP*
MAX8903YETI+T
-40°C to +85°C
28 Thin QFN-EP*
Visit www.maximintegrated.com/products/patents for
product patent marking information.

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