MAX8903A_11 Datasheet, PDF (1/30 Pages) Maxim Integrated Products – 2A 1-Cell Li DC-DC Chargers for USB and Adapter Power Thermistor Monitor

19-4410; Rev 4; 5/11
EVAALVUAAILTAIOBNLEKIT
2A 1-Cell Li+ DC-DC Chargers for USB
and Adapter Power
General Description
The MAX8903A–MAX8903E/MAX8903G/MAX8903H/
MAX8903J/MAX8903Y are integrated 1-cell Li+ charg-
ers 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 current-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
PDAs, Palmtops, and
Wireless Handhelds
Personal Navigation
Devices
Smart Cell Phones
Portable Multimedia
Players
Mobile Internet Devices
Ultra Mobile PCs
Selector Guide appears at end of data sheet.
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
50mΩ 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
Ordering Information
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*
MAX8903YETI+T
-40°C to +85°C 28 Thin QFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
**Future product—contact factory for availability.
T = Tape and reel.
Typical Operating Circuit
AC
LX
CS
ADAPTER
OR USB _DC
PWM
STEP-DOWN
USB
USB
CHARGE
CURRENT
SYS
LOAD
CURRENT
CHARGE
AND
SYS LOAD
SWITCH
SYSTEM
LOAD
BAT BATTERY
MAX8903_
GND
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
Pin Configuration appears at end of data sheet.
________________________________________________________________ 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.