19-4497; Rev 0; 7/09
High-Efficiency Power-Management IC with I
2
C
Control for 2-Cell Li+ Battery Operated Devices
General Description
The MAX8904 power-management IC provides a com-
plete power-supply solution for 2-cell Li+ handheld/Li-Poly
applications such as point-of-sale terminals, digital SLR
cameras, digital video cameras and ultra-mobile PCs.
The MAX8904 includes five step-down converters (1V2,
1V8, 3V3, 5V0, and ADJ) with internal MOSFETs and
+1%/-3% accurate output voltages for processor core,
memory, I/O, and other system power rail requirements.
LCD backlighting is supported by a WLED boost con-
verter that can provide 35mA for up to 8 WLEDs. This
boost converter is also configurable as a 6-bit program-
mable voltage source that can provide up to 63mA of
output current. A 500mA, internal MOSFET, current-lim-
ited switch (CLS), allows system designers to control
input power to external peripheral devices.
The MAX8904 controls an external n-MOSFET for input
overvoltage protection (13.5V, typ) and an external
p-MOSFET for reverse polarity protection (up to -28V) of
downstream circuits. System input current monitoring
for power management is facilitated by an on-board
current-sense amplifier (CSA) with differential inputs
and a 1.2V full scale, ground-referenced analog output.
A 400kHz, I
2
C interface supports output voltage setting
of the ADJ power rail and boost regulator (voltage
source mode), WLED current setting for the boost regu-
lator (WLED current regulator mode), GPIO control, and
enable/disable of ADJ, 5V0, boost regulator, CSA
blocks. The I
2
C interface also enables the host proces-
sor to read on-board fault status registers when inter-
rupted by the MAX8904
FLT
pin under system fault
conditions.
An emergency shutdown input,
SHDN
allows convert-
ers preselected through I
2
C to turn off immediately
under power-fail conditions, thus saving valuable
firmware execution time. An uncommitted, active-low,
14V open-drain comparator (CMP) with a 1.25V internal
reference is also provided in the MAX8904. The
MAX8904 PWREN logic input turns on the 1V2, 1V8,
3V3, and 5V0 default power rails.
The MAX8904 is available in a 56-pin, 7mm x 7mm
TQFN package.
Features
o
3.4V to 13.2V Input Voltage Range
o
1MHz, Up to 90% Efficient, Synchronous DC-DC
Step-Down Converters
o
Power Converters 1V2, 1V8, and ADJ Operated
Out-of-Phase with Respect to 3V3 and 5V0
o
667kHz Step-Up Converter Provides Up to 32V
Output for Driving Up to Eight WLEDs
o
Internal Compensation on All Power Converters
o
Fast Line and Load Transient Responses
o
Internal Soft-Start and Short-Circuit Protection on
All Power Converter Outputs
o
Input Overvoltage and Reverse Polarity Protection
o
250ms Fault Timer-Based Protection for Overload,
Short Circuit
o
I
2
C Serial Interface for On/Off Control, Output
Voltage, WLED Current, GPIO Setting, Fault
Monitoring
o
< 15µA Standby Current Over Operating Voltage
Range and Temperature
o
Compact, 56-Pin, 7mm x 7mm TQFN Package
MAX8904
Ordering Information
PART
MAX8904ETN+T
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
56 THIN QFN-EP*
(7mm x 7mm)
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
T = Tape and reel.
Typical Operating Circuit
V
IN
CS-
MAX8904
V
EXT
CS+
CSOUT
OVGATE
OVPWR
RPGATE
LVRPWR
LVROUT
LVRIN5V
V
IN
PWREN
CLSIN
CLSOUT
CMPI
CMPO
SDA
SCL
SHDN
FLT
1V2LX
1V8LX
3V3LX
5V0LX
ADJLX1
ADJLX2
BSTLX
1.2V, 600mA
1.8V, 975mA
3.3V, 1250mA
5V, 800mA
3.0V TO 5.067V,
1500mA
V
IN
V
IN
Applications
Point-of-Sale Terminals
Digital Video Cameras
Digital SLR Cameras
Ultra-Mobile PCs
Pin Configuration appears at end of data sheet.
PCS
GPIO0
1mA TO 63mA
UP TO 8 WLEDs
8-BIT GPIO
PORT
GPIO7
GND
________________________________________________________________
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.
High-Efficiency Power-Management IC with I
2
C
Control for 2-Cell Li+ Battery Operated Devices
MAX8904
ABSOLUTE MAXIMUM RATINGS
OVPWR to GND......................................................-0.3V to +30V
RPGATE to GND.....................................................-0.3V to +17V
OVPWR to RPGATE................................................-0.3V to +22V
OVGATE to CS+ .......................................................-0.3V to +6V
BSTFB to GND........................................................-0.3V to +40V
BSTLX to Exposed Pad (EP) ..................................-0.3V to +40V
BSTSW to BSTIN ....................................................-16V to +0.3V
LVRPWR, BSTIN, BSTSW, 1V2IN, 3V3IN, 1V8IN, ADJIN,
5V0IN,
CMPO,
CLSIN to EP...............................-0.3V to +16V
GPIO_ to EP..............................................................-0.3V to +6V
CS+, CS- to GND ...................................................-0.3V to +16V
CS+ to CS- ............................................................-0.3V to +0.3V
CLSOUT to GND ....................................-0.3V to (V
CLSIN
+ 0.3V)
LVROUT to GND.................................-0.3V to (V
LVRPWR
+ 0.3V)
1V2FB, 1V8FB, 3V3FB, 5V0FB, ADJFB, REF, CSOUT,
CMPI to GND .................................-0.3V to (V
LVRIN5V
+ 0.3V)
1V2BST to 1V2LX, 1V8BST to 1V8LX, 3V3BST to 3V3LX,
5V0BST to 5V0LX, ADJBST to ADJLX_................-0.3V to +6V
LVRIN5V, LVROUT,
SHDN,
PWREN,
FLT,
SDA, SCL,
GPIOPWR to GND ...............................................-0.3V to +6V
PCS to GND ...........................................-0.3V to (V
BSTIN
+ 0.3V)
EP to GND .............................................................-0.3V to +0.3V
GPIOPWR to LVRIN5V..............................................-6V to +0.3V
LVROUT to LVRIN5V .............................................-0.3V to +0.3V
ADJLX_, 5V0LX, 3V3LX, 1V8LX, 1V2LX,
BSTLX (Note 1)........................................................±1.7A
RMS
Continuous Power Dissipation (T
A
= +70°C)
56-Pin TQFN-EP Single-Layer PCB
(derate 27.8mW/°C above +70°C) ............................2222mW
56-Pin TQFN-EP Multilayer PCB
(derate 40mW/°C above +70°C) ...............................3200mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note 2) .....0.8°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note 2)
Single-Layer PCB ........................................................36°C/W
Multilayer PCB .............................................................25°C/W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
_LX pins have internal clamp diodes to _IN and EP. Applications that forward bias these diodes should take care not to exceed
the device’s power-dissipation limits.
Note 2:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
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
_IN
= 7.2V, EP = GND, V
PWREN
= 5V, _LX unconnected, C
REF
= 0.1µF; when V
_IN
is specified, it implies all _IN pins; T
A
= -40°C to
+85°C. Typical values are at T
A
= +25°C, unless otherwise noted. Limits are 100% production tested at T
A
= +25°C. Limits over the
operating temperature range are guaranteed by design and characterization.)
PARAMETER
COMMON BLOCKS
V
_IN
falling, OVP circuit not used
Input Operating Supply Range
V
_IN
V
_IN
rising, OVP circuit not used
V
_IN
falling, OVP circuit used
V
_IN
rising, OVP circuit used
Input Standoff Voltage
Standby Mode Supply Current
V
OVPWR
I
_IN
+
I
LVRPWR
+
I
CS_
∆I
QLVRPWR
+ I
1V2IN
+
I
1V8IN
+
I
3V3IN
+
I
5V0IN +
I
5V0FB
V
_IN
= 13.2V; all channels off
5.5
µA
3.6
5.8
3.6
5.8
14
14
12.8
13.2
28
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Quiescent Supply Current
(CH7 + CH2 + CH3 + CH4 Only)
No switching, V
1V2FB
= 1.3V,
V
1V8FB
= 1.9V, V
3V3FB
= 3.4V,
V
5V0FB
= 5.1V
100
165
µA
2
_______________________________________________________________________________________
High-Efficiency Power-Management IC with I
2
C
Control for 2-Cell Li+ Battery Operated Devices
ELECTRICAL CHARACTERISTICS (continued)
(V
_IN
= 7.2V, EP = GND, V
PWREN
= 5V, _LX unconnected, C
REF
= 0.1µF; when V
_IN
is specified, it implies all _IN pins; T
A
= -40°C to
+85°C. Typical values are at T
A
= +25°C, unless otherwise noted. Limits are 100% production tested at T
A
= +25°C. Limits over the
operating temperature range are guaranteed by design and characterization.)
PARAMETER
REF Output Voltage
OSC Frequency
LVROUT Output Voltage
LVRPWR Undervoltage Lockout
Threshold
LVRIN5V Undervoltage Lockout
Threshold
SHDN
Input High Voltage
SHDN
Input Low Voltage
SHDN
Pullup Resistance to
LVRIN5V
SHDN
Pulldown Resistance
to GND
PWREN Input High Voltage
PWREN Input Low Voltage
PWREN Pulldown Resistance
PWREN Deglitch Delay
FLT
Output-Voltage Low
FLT
Open-Drain Leakage Current
FAULT Timer Delay
Overtemperature Warning Flag
Overtemperature Warning Flag
Hysteresis
Thermal Shutdown Latch
Threshold
INPUT VOLTAGE PROTECTION
OVPWR Undervoltage Lockout
Threshold
OVPWR_UVLO_Rising to
OVGATE Startup Delay
OVP Threshold
OVGATE Charge Current
OVGATE Discharge Resistance
RPGATE Pulldown Resistor
RPGATE Clamp Voltage
t
STARTUP
V
OVP
V
OVPWR
rising
V
OVPWR
falling
V
OVPWR
> V
OVPWR_UVLO_RISING
V
OVPWR
rising
Hysteresis
13.3
3.75
2.7
4
2.85
32
13.65
0.17
10
40
50
14V
≤
V
OVPWR
≤
28V
16
19
14
4.25
3.0
V
ms
V
µA
Ω
kΩ
V
(Note 3)
140
t
FAULT
Rising (Note 3) (bit D3 of register 0Dh)
110
V
FLT
Rising
I
FLT
= 20mA
V
FLT
= 5.5V
T
A
= +25°C
T
A
= +85°C
0
0.01
0.1
250
120
10
152
165
130
V
IH
V
IL
3.4V < V
LVRPWR
< 14V
3.4V < V
LVRPWR
< 14V
1
10
0.4
0.1
1.6
0.5
V
IH
V
IL
SYMBOL
V
REF
f
OSC
5.4V < V
LVRPWR
< 14V
V
LVRPWR
rising
V
LVRPWR
falling
V
LVRIN5V
rising
V
LVRIN5V
falling
3V < V
LVRIN5V
< 5.5V
3V < V
LVRIN5V
< 5.5V
1
2
1.6
0.5
I
REF
= 0µA
I
REF
= 10µA
0.9
4.9
5.3
3.2
CONDITIONS
MIN
1.240
TYP
1.250
1.249
1
5.1
5.55
3.4
3.45
2.6
1.1
5.3
5.8
3.6
MAX
1.260
UNITS
V
MHz
V
V
V
V
V
MΩ
MΩ
V
V
MΩ
µs
V
µA
ms
°C
°C
°C
MAX8904
I
OVGATE_CHG
V
OVGATE
= 7.2V
R
DCHG
V
CS+
= 14.1V, V
OVGATE
= 15.1V
R
RPGATE
V
CLAMP
_______________________________________________________________________________________
3
High-Efficiency Power-Management IC with I
2
C
Control for 2-Cell Li+ Battery Operated Devices
MAX8904
ELECTRICAL CHARACTERISTICS (continued)
(V
_IN
= 7.2V, EP = GND, V
PWREN
= 5V, _LX unconnected, C
REF
= 0.1µF; when V
_IN
is specified, it implies all _IN pins; T
A
= -40°C to
+85°C. Typical values are at T
A
= +25°C, unless otherwise noted. Limits are 100% production tested at T
A
= +25°C. Limits over the
operating temperature range are guaranteed by design and characterization.)
PARAMETER
CH1 (CURRENT-LIMITED SWITCH)
Current-Limited Switch
On-Resistance
Current Limit
Overcurrent Fault Latch-Off Delay
Fault Voltage
Thermal Loop Threshold
CLSOUT Leakage Current
R
ONCLS
I
LIMCLS
t
OLFLT
V
ACT
THM
TH
I
CLSOUTLKG
V
CLSIN
- V
CLSOUT
> 1V, 150mV hysteresis
Current-limit-foldback temperature
threshold (Note 3)
V
CLSIN
= 14V,
V
CLSOUT
= 0
No load
T
A
= +25°C
T
A
= +85°C
1.800
110
I
CLS
= 400mA
V
CLSIN
= 12V, V
CLSOUT
= 9V
200
450
250
1
120
0.01
0.1
1.818
1
-2.5
V
1V8IN
= 3.4V to 14V
(Note 4)
I
1V8LXLKG
I
1V8BSTLKG
R
ONLS1V8
R
ONHS1V8
I
LIMHS1V8
Rising
Falling
1.3
V
1V8LX
= 0, 14V,
V
1V8IN
= 14V
V
1V8BST
= 5V + V
1V8IN
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
-5
0.04
150
0.01
0.1
0.01
0.1
0.185
0.27
1.43
10
(Bit D3 of register 0Fh)
94
90
1
PWREN = GND
350
2
1.6
0.1
+5
1.836
130
1
300
425
600
m_
mA
ms
V
°C
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CH2 (1V8 STEP-DOWN CONVERTER)
Output Voltage
Operating Frequency
Load Regulation
Line Regulation
Idle-Mode Trip Level
1V8LX Leakage Current
1V8BST Leakage Current
Low-Side Switch On-Resistance
High-Side Switch On-Resistance
High-Side Switch Current Limit
Low-Side Switch Turn-Off Current
Output-OK (1V8OK) Threshold
Soft-Start Rate
LX Discharge Resistance
Output-OK (1V8OK) Fault
Blanking Time After Soft-Start
Done
V
1V8FB
f
1V8LX
V
MHz
%/A
%/V
mA
µA
µA
_
_
A
mA
%
V/ms
_
ms
4
_______________________________________________________________________________________
High-Efficiency Power-Management IC with I
2
C
Control for 2-Cell Li+ Battery Operated Devices
ELECTRICAL CHARACTERISTICS (continued)
(V
_IN
= 7.2V, EP = GND, V
PWREN
= 5V, _LX unconnected, C
REF
= 0.1µF; when V
_IN
is specified, it implies all _IN pins; T
A
= -40°C to
+85°C. Typical values are at T
A
= +25°C, unless otherwise noted. Limits are 100% production tested at T
A
= +25°C. Limits over the
operating temperature range are guaranteed by design and characterization.)
PARAMETER
Output Voltage
Operating Frequency
Load Regulation
Line Regulation
Idle-Mode Trip Level
3V3LX Leakage Current
3V3BST Leakage Current
Low-Side Switch On-Resistance
High-Side Switch On-Resistance
High-Side Switch Current Limit
Low-Side Switch Turn-Off Current
Output-OK (3V3OK) Threshold
Maximum Duty Cycle
Soft-Start Rate
LX Discharge Resistance
Output-OK (3V3OK) Fault
Blanking Time After Soft-Start
Done
CH4 (5V0 STEP-DOWN CONVERTER)
Output Voltage
Operating Frequency
Load Regulation
Line Regulation
Idle-Mode Trip Level
5V0LX Leakage Current
5V0BST Leakage Current
Low-Side Switch On-Resistance
High-Side Switch On-Resistance
High-Side Switch Current Limit
Low-Side Switch Turn-Off Current
I
5V0LXLKG
V
5V0IN
= 5.4V to 14V
(Note 4)
V
5V0LX
= 0, 14V,
V
5V0IN
= 14V
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
-5
V
5V0FB
f
5V0LX
No load
5.000
5.050
1
-1.25
0.04
60
+0.01
0.1
0.01
0.1
0.27
0.27
1.26
1.4
10
1.54
0.1
+5
5.100
V
MHz
%/A
%/V
mA
µA
µA
_
_
A
mA
PWREN = GND
(Bit D4 of register 0Fh)
Rising
Falling
I
3V3LXLKG
I
3V3BSTLKG
R
ONLS3V3
R
ONHS3V3
I
LIMHS3V3
1.8
V
3V3IN
= 3.4V to 14V
(Note 4)
V
3V3LX
= 0, 14V,
V
3V3IN
= 14V
V
3V3BST
= 5V + V
3V3IN
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
-5
SYMBOL
V
3V3FB
f
3V3LX
No load
CONDITIONS
MIN
3.349
TYP
3.383
1
-1.1
0.04
150
0.01
0.1
0.01
0.1
0.185
0.185
2
10
94
90
95
1
175
2
2.2
0.1
+5
MAX
3.416
UNITS
V
MHz
%/A
%/V
mA
µA
µA
_
_
A
mA
%
%
V/ms
_
ms
MAX8904
CH3 (3V3 STEP-DOWN CONVERTER)
I
5V0BSTLKG
V
5V0BST
= 5V + V
5V0IN
R
ONLS5V0
R
ONHS5V0
I
LIMHS5V0
_______________________________________________________________________________________
5
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