19-4410; Rev 4; 5/11
KIT
ATION
EVALU
E
BL
AVAILA
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.
o
o
o
o
Features
Efficient DC-DC Converter Eliminates Heat
4MHz Switching for Tiny External Components
Instant On—Works with No/Low Battery
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
Thermistor Monitor
Integrated Current-Sense Resistor
No External MOSFETs or Diodes
4.1V to 16V Input Operating Voltage Range
MAX8903A–E/G/H/J/Y
o
o
o
o
Ordering Information
PART
MAX8903AETI+T
MAX8903BETI+T
MAX8903CETI+T
MAX8903DETI+T
MAX8903EETI+T
MAX8903GETI+T
MAX8903HETI+T
MAX8903JETI+T**
MAX8903YETI+T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 Thin QFN-EP*
28 Thin QFN-EP*
28 Thin QFN-EP*
28 Thin QFN-EP*
28 Thin QFN-EP*
28 Thin QFN-EP*
28 Thin QFN-EP*
28 Thin QFN-EP*
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
ADAPTER
OR USB
LX
DC
CS
SYS
LOAD
CURRENT
CHARGE
AND
SYS LOAD
SWITCH
SYSTEM
LOAD
Applications
PDAs, Palmtops, and
Wireless Handhelds
Personal Navigation
Devices
Smart Cell Phones
Portable Multimedia
Players
Mobile Internet Devices
Ultra Mobile PCs
PWM
STEP-DOWN
USB
CHARGE
CURRENT
USB
BAT
BATTERY
Selector Guide appears at end of data sheet.
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
MAX8903_
GND
Pin Configuration appears at end of data sheet.
1
________________________________________________________________
Maxim Integrated Products
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.
2A 1-Cell Li+ DC-DC Chargers for USB
and Adapter Power
MAX8903A–E/G/H/J/Y
ABSOLUTE MAXIMUM RATINGS
DC, LX to GND .......................................................-0.3V to +20V
DCM to GND ..............................................-0.3V to (V
DC
+ 0.3V)
DC to SYS .................................................................-6V to +20V
BST to GND ...........................................................-0.3V to +26V
BST TO LX ................................................................-0.3V to +6V
USB to GND .............................................................-0.3V to +9V
USB to SYS..................................................................-6V to +9V
VL to GND ................................................................-0.3V to +6V
THM, IDC, ISET, CT to GND........................-0.3V to (V
VL
+ 0.3V)
DOK, FLT, CEN, UOK, CHG,
USUS,
BAT, SYS, IUSB, CS to GND ................................-0.3V to +6V
SYS to BAT ...............................................................-0.3V to +6V
PG, EP (exposed pad) to GND .............................-0.3V to +0.3V
DC Continuous Current (total in two pins)......................2.4A
RMS
USB Continuous Current.......................................................1.6A
LX Continuous Current (total in two pins).......................2.4A
RMS
CS Continuous Current (total in two pins) ......................2.4A
RMS
SYS Continuous Current (total in two pins) .......................3A
RMS
BAT Continuous Current (total in two pins) .......................3A
RMS
VL Short Circuit to GND .............................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
28-Pin Thin QFN-EP
Multilayer (derate 28.6mW/°C above +70°C) ..........2286mW
28-Pin Thin QFN-EP
Single-Layer (derate 20.8mW/°C above +70°C)...1666.7mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature Range ............................-40°C to +150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DC
= V
USB
= 5V, V
BAT
= 4V, circuit of Figure 2, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Note 1)
PARAMETER
DC INPUT
DC Operating Range
DC Undervoltage Threshold
DC Overvoltage Threshold
When V
DOK
goes low, V
DC
rising, 500mV typical hysteresis
No valid USB input
Valid USB input
4.15
3.9
4.0
16.5
4.0
4.3
17
2.3
15
1
1
0.10
0.15
0.15
Assumes a 40mΩ inductor resistance (R
L
)
When SYS regulation and charging stops, V
DC
falling,
200mV hysteresis
0
0.31
15
100
V
DC
= 8V, V
BAT
= 4V
V
DC
= 5V, V
BAT
= 3V
V
DC
= 9V, V
BAT
= 4V
V
DC
= 9V, V
BAT
= 3V
0.5
R
IDC
= 3kΩ
V
DC
= 6V, V
SYS
= 4V
R
IDC
= 6kΩ
R
IDC
= 12kΩ
1900
950
450
2000
1000
500
70
4
3
1
1
2
2100
1050
550
mA
A
30
2
2
0.25
Ω
Ω
Ω
mV
ns
ns
mA
16
4.1
4.4
17.5
4
V
V
V
CONDITIONS
MIN
TYP
MAX
UNITS
When V
DOK
goes high, V
DC
rising, 500mV typical
hysteresis
Charger enabled, no switching, V
SYS
= 5V
Charger enabled, f = 3MHz, V
DC
= 5V
DC Supply Current
Charger enabled, V
CEN
= 0V, 100mA USB mode (Note 2)
Charger enabled, V
CEN
= 5V, 100mA USB mode (Note 2)
V
DCM
= 0V, V
USUS
= 5V
DC High-Side Resistance
DC Low-Side Resistance
DC-to-BAT Dropout Resistance
DC-to-BAT Dropout Voltage
Minimum Off Time (t
OFFMIN
)
Minimum On Time (t
ONMIN
)
MAX8903A/B/C/D/E/H/J/Y
Switching Frequency (f
SW
)
MAX8903G
DC Step-Down Output Current-
Limit Step Range
DC Step-Down Output Current
Limit (I
SDLIM
)
MHz
2
_______________________________________________________________________________________
2A 1-Cell Li+ DC-DC Chargers for USB
and Adapter Power
ELECTRICAL CHARACTERISTICS (continued)
(V
DC
= V
USB
= 5V, V
BAT
= 4V, circuit of Figure 2, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Note 1)
PARAMETER
DC Soft-Start Time
DC Output Current
500mA USB Mode (Note 3)
DC Output Current
100mA USB Mode (Note 2)
SYS to DC Reverse Current
Blocking
USB INPUT
USB Operating Range
USB Standoff Voltage
USB Undervoltage Threshold
USB Overvoltage Threshold
USB Current Limit
When V
UOK
goes low, V
USB
rising, 500mV hysteresis
When V
UOK
goes high, V
USB
rising, 500mV hysteresis
V
IUSB
= 0V (100mA setting)
V
IUSB
= 5V (500mA setting)
I
SYS
= I
BAT
= 0mA, V
CEN
= 0V
USB Supply Current
Minimum USB to BAT Headroom
USB to SYS Dropout Resistance
USB Soft-Start Time
SYS OUTPUT
Minimum SYS Regulation Voltage
(V
SYSMIN
)
I
SYS
= 1A,
V
BAT
< V
SYSMIN
MAX8903A/MAX8903B/MAX8903E/
MAX8903G/MAX8903Y
MAX8903C/MAX8903D/MAX8903H/
MAX8903J
MAX8903A/MAX8903C/
MAX8903D/MAX8903H/MAX8903Y
Regulation Voltage
I
SYS
= 0A
MAX8903B/MAX8903E/
MAX8903G
MAX8903J
MAX8903A/MAX8903C/
MAX8903D/MAX8903H
4.3
4.265
3.0
V
3.4
4.4
4.325
4.5
40
mV/A
25
0.07
0.01
0.05
50
1.8
75
1.9
0.1
100
2.0
Ω
µA
Ω
mV
V
4.5
4.395
V
V
USB
rising
V
DC
falling below DC UVLO to initiate USB soft-start
I
SYS
= I
BAT
= 0mA, V
CEN
= 5V
V
USUS
= 5V (USB suspend mode)
0
3.95
6.8
90
450
4.0
6.9
95
475
1.3
0.8
0.115
15
0.2
1
20
4.1
6.3
8
4.05
7.0
100
500
3
2
0.25
30
0.35
mV
Ω
ms
µs
mA
V
V
V
V
mA
No valid USB input
Valid USB input before soft-start
V
DCM
= 0V, V
IUSB
= 5V
V
DCM
= 0V, V
IUSB
= 0V
V
SYS
= 5.5V, V
DC
= 0V
450
90
CONDITIONS
MIN
TYP
1
20
475
95
0.01
500
100
MAX
UNITS
ms
µs
mA
mA
µA
MAX8903A–E/G/H/J/Y
Load Regulation
CS to SYS Resistance
SYS to CS Leakage
BAT to SYS Resistance
BAT to SYS Reverse Regulation
Voltage
SYS Undervoltage Threshold
MAX8903B/MAX8903E/
MAX8903G/MAX8903J/MAX8903Y
V
DC
= 6V, V
DCM
= 5V, V
SYS
= 4V, I
CS
= 1A
V
SYS
= 5.5V, V
DC
= V
CS
= 0V
V
DC
= V
USB
= 0V, V
BAT
= 4.2V, I
SYS
= 1A
V
USB
= 5V, V
DC
= 0V, V
IUSB
= 0V, I
SYS
= 200mA
SYS falling, 200mV hysteresis (Note 4)
I
SYS
= 0 to 2A
_______________________________________________________________________________________
3
2A 1-Cell Li+ DC-DC Chargers for USB
and Adapter Power
MAX8903A–E/G/H/J/Y
ELECTRICAL CHARACTERISTICS (continued)
(V
DC
= V
USB
= 5V, V
BAT
= 4V, circuit of Figure 2, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Note 1)
PARAMETER
BATTERY CHARGER
MAX8903A/
MAX8903B/
MAX8903C/
MAX8903G/
MAX8903H
BAT Regulation Voltage
(V
BATREG
)
I
BAT
= 0mA
MAX8903D/
MAX8903E
MAX8903J
MAX8903Y
Charger Restart Threshold
BAT Prequal Threshold (V
BATPQ
)
Prequal Charge Current
Fast-Charge Current
DONE Threshold (I
TERM
)
R
ISET
Resistor Range
ISET Output Voltage
ISET Current Monitor Gain
BAT Leakage Current
Charger Soft-Start Time
Charger Thermal Limit
Temperature
Charger Thermal Limit Gain
CHARGER TIMER
Prequalification Time
Fast-Charge Time
Top-Off Timer (t
TOP-OFF
)
Timer Accuracy
Timer Extend Current Threshold
Timer Suspend Current Threshold
Percentage of fast-charge current below which the timer
clock operates at half-speed
Percentage of fast-charge current below which timer
clock pauses
C
CT
= 0.15µF
C
CT
= 0.15µF
MAX8903A/MAX8903C/MAX8903D/MAX8903H/
MAX8903J/MAX8903Y (fixed)
MAX8903B/MAX8903E/MAX8903G, C
CT
= 0.15µF
-15
40
16
50
20
33
660
15
132
+15
60
24
min
min
s
min
%
%
%
Charge current = 0 at +120°C
No DC or USB input
With valid input power, V
CEN
= 5V
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
4.179
4.200
4.221
CONDITIONS
MIN
TYP
MAX
UNITS
4.158
4.079
4.059
4.328
4.307
4.129
4.109
-150
2.9
2.4
1800
900
450
0.6
4.200
4.100
4.100
4.350
4.350
4.150
4.150
-100
3.0
2.5
10
2000
1000
500
10
4.242
4.121
4.141
4.372
4.394
4.171
4.192
-60
3.1
2.6
%
2200
1100
550
%
2.4
kΩ
V
mA/A
4
6
µA
ms
°C
%/°C
mA
mV
V
V
Change in V
BAT
from DONE to fast-charge
V
BAT
rising
180mV hystersis
MAX8903A/MAX8903C/MAX8903D/
MAX8903H/MAX8903J/MAX8903Y
MAX8903B/MAX8903E/MAX8903G
Percentage of fast-charge current set at ISET
R
ISET
= 600Ω
R
ISET
= 1.2kΩ (MAX8903A/MAX8903C/MAX8903D)
R
ISET
= 2.4kΩ
Percentage of fast-charge, I
BAT
decreasing
1.5
1.25
0.05
3
1.0
100
5
4
_______________________________________________________________________________________
2A 1-Cell Li+ DC-DC Chargers for USB
and Adapter Power
ELECTRICAL CHARACTERISTICS (continued)
(V
DC
= V
USB
= 5V, V
BAT
= 4V, circuit of Figure 2, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Note 1)
PARAMETER
THERMISTOR MONITOR
THM Threshold, Hot
THM Threshold, Cold
THM Threshold, Disabled
THM Threshold DC, USB Enable
When charging is suspended, 1% hysteresis
When charging is suspended, 1% hysteresis
THM function is disabled below this voltage
MAX8903B/MAX8903E/MAX8903G
THM = GND or VL;
T
A
= +25°C
THM = GND or VL;
T
A
= +85°C
THM = GND or VL;
T
A
= -40°C to +85°C
-0.200
0.27 x
V
VL
0.73 x
V
VL
0.0254
x V
VL
0.83 x
V
VL
-0.100
0.28 x
V
VL
0.74 x
V
VL
0.03 x
V
VL
0.87 x
V
VL
±0.001
±0.010
±0.001
+0.200
0.29 x
V
VL
0.75 x
V
VL
0.036 x
V
VL
0.91 x
V
VL
+0.200
µA
V
V
V
V
CONDITIONS
MIN
TYP
MAX
UNITS
MAX8903A–E/G/H/J/Y
THM Input Leakage
MAX8903A/MAX8903C/
MAX8903D/MAX8903H/
MAX8903J/MAX8903Y
MAX8903B/MAX8903E/
MAX8903G
High level
THERMAL SHUTDOWN, VL, AND LOGIC I/O:
CHG, FLT, DOK, UOK,
DCM,
CEN,
USUS, IUSB
1.3
0.4
50
T
A
= +25°C
T
A
= +85°C
-1.000
±0.001
±0.010
+1.000
Logic-Input Thresholds
(DCM,
CEN,
USUS, IUSB)
Low level
Hysteresis
V
INPUT
= 0V to 5.5V
(MAX8903A/MAX8903C/
MAX8903D/MAX8903H/
MAX8903J/MAX8903Y)
V
INPUT
= 0V to 5.5V
(MAX8903B/MAX8903E/
MAX8903G)
Logic-Input Leakage Current
(DCM)
Logic Output Voltage, Low
(CHG,
FLT, DOK, UOK)
V
DCM
= 0V to 16V
V
DC
= 16V
Sinking 1mA
Sinking 10mA
T
A
= +25°C
T
A
= +85°C
V
mV
Logic-Input Leakage Current
(CEN, USUS, IUSB)
µA
+0.200
1
50
1
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= +85°C
-0.200
±0.001
0.001
0.01
8
80
0.001
0.01
µA
mV
µA
Open-Drain Output Leakage
V
OUT
= 5.5V
Current, High (CHG,
FLT, DOK, UOK)
_______________________________________________________________________________________
5
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