Maxim MAX1553 High-efficiency, 40v step-up converters for 2 to 10 white led Datasheet

19-2875; Rev 0; 6/03
KIT
ATION
EVALU
E
L
B
AVAILA
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
Features
♦ Constant-Current Regulation for Even LED
Illumination
♦ Internal 40V MOSFET Switch Capable of Driving
10 LEDs
♦ Small, Low-Profile External Components
♦ 2.7V to 5.5V Input Range
♦ Up to 88% Efficiency Driving 6 LEDs
♦ Up to 82% Efficiency Driving 9 LEDs
(20mA, VCC = 3.6V)
♦ Analog or PWM Control of LED Intensity
♦ Optimized for Low Input Ripple
♦ Soft-Start to Minimize Inrush Current
♦ 3mm x 3mm 8-Pin TDFN Package
Applications
Cellular Phones
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
PDA, Palmtop, and Wireless Handhelds
MAX1553ETA
-40°C to +85°C
8 TDFN 3mm x 3mm
Color Display Backlight
MAX1554ETA
-40°C to +85°C
8 TDFN 3mm x 3mm
Dual Mode is a trademark of Maxim Integrated Products, Inc.
Pin Configuration
Typical Operating Circuit
TOP VIEW
2.7V TO 5.5V
INPUT
ON
OFF
PWM
OR
DC CONTROL
VCC
LX
EN
OV
MAX1553
MAX1554
BRT
SS
FB
WHITE
LEDS
GND
1
VCC
2
EN
3
BRT
4
MAX1553
MAX1554
8
LX
7
0V
6
SS
5
FB
GND
TDFN
3mm x 3mm
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX1553/MAX1554
General Description
The MAX1553/MAX1554 drive white LEDs in series with
a constant current to provide efficient display backlighting in cellular phones, PDAs, and other hand-held
devices. The step-up converter includes an internal
40V, low RDSON, N-channel MOSFET switch for high
efficiency and maximum battery life. The MAX1553 has
a current limit of 480mA for driving two to six white
LEDs, while the MAX1554 has a current limit of 970mA
for driving up to 10 white LEDs.
A single analog/PWM Dual Mode input provides two
simple means of brightness adjustment. A separate
enable input provides on/off control. Soft-start minimizes
inrush current during startup.
The MAX1553/MAX1554 are available in space-saving
8-pin TDFN 3mm x 3mm packages.
MAX1553/MAX1554
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
ABSOLUTE MAXIMUM RATINGS
VCC, FB, OV to GND..............................................-0.3V to +6.0V
LX to GND ..............................................................-0.3V to +45V
EN, BRT, SS to GND...................................-0.3V to (VCC + 0.3V)
ILX ...................................................................................0.9ARMS
Continuous Power Dissipation (TA = +70°C)
8-Pin 3mm x 3mm TDFN
(derate 24.4mW/°C above +70°C) .............................1951mW
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
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
(VCC = 3.3V, VOV = 0V, COUT = 1µF, RSENSE = 10Ω, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Supply Voltage
Undervoltage Lockout Threshold
Quiescent Current
CONDITIONS
MIN
TYP
MAX
MAX1553
2.7
5.5
MAX1554
3.15
5.50
VCC rising or falling, 35mV hysteresis typical
2.35
2.5
2.65
Not switching
0.33
0.65
Switching
0.44
0.9
TA = +25°C
0.1
1
TA = +85°C
1
Shutdown Supply Current
VEN = 0V
OV Threshold
Rising edge
1.25
1.33
TA = +25°C
1.18
1
200
TA = +85°C
10
OV Input Bias Current
VOV = 1V
BRT Input Resistance
0 < VBRT < 1.5V, EN = VCC
200
Maximum On-Time
VCC = 3.3V
2.0
On-Time Constant (K)
tON = K / VCC
400
600
3.4
4.8
UNITS
V
V
mA
µA
V
nA
kΩ
TIMING CONTROL
6.3
Minimum Off-Time
µs
µs-V
150
250
350
192
203
212
ns
ERROR AMPLIFIER
FB Threshold
FB Input Bias Current
VBRT = 1.25V
VBRT = 3.3V
VFB = 1.0V
280
TA = +25°C
15
TA = +85°C
100
200
mV
nA
N-CHANNEL SWITCH
LX On-Resistance
2
0.8
_______________________________________________________________________________________
1.4
Ω
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
(VCC = 3.3V, VOV = 0V, COUT = 1µF, RSENSE = 10Ω, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
LX Current Limit
LX Leakage Current
CONDITIONS
MIN
TYP
MAX
MAX1553
300
480
600
MAX1554, VCC = 4.2V
600
970
1200
TA = +25°C
0.1
5
TA = +85°C
1
VLX = 38V,
VEN = 0V
UNITS
mA
µA
SHUTDOWN CONTROL
EN Logic-Level High
1.8
V
EN Logic-Level Low
EN Input Current
0.4
VEN = 0V or 5.5V
TA = +25°C
0.01
TA = +85°C
0.1
1
V
µA
ELECTRICAL CHARACTERISTICS
(VCC = 3.3V, VOV = 0V, COUT = 1µF, RSENSE = 10Ω, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
Supply Voltage
Undervoltage Lockout Threshold
Quiescent Current
MIN
MAX
MAX1553
CONDITIONS
2.7
5.5
MAX1554
3.15
5.50
VCC rising or falling, 35mV hysteresis typical
2.35
2.65
Not switching
0.65
Switching
0.9
UNITS
V
V
mA
OV Threshold
Rising edge
1.18
1.33
V
BRT Input Resistance
0 < VBRT < 1.5V, EN = VCC
200
600
kΩ
TIMING CONTROL
Maximum On-Time
VCC = 3.3V
Minimum Off-Time
2.0
4.8
µs
150
350
ns
192
217
mV
1.4
Ω
ERROR AMPLIFIER
FB Threshold
VBRT = 1.25V
N-CHANNEL SWITCH
LX On-Resistance
LX Current Limit
MAX1553
300
600
MAX1554, VCC = 4.2V
600
1200
mA
SHUTDOWN CONTROL
EN Logic-Level High
EN Logic-Level Low
1.8
V
0.4
V
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
_______________________________________________________________________________________
3
MAX1553/MAX1554
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(MAX1553 driving six white LEDs, VCC = VEN = 3.6V, Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
VCC = 3.6V
70
VCC = 3V
60
80
VCC = 3.6V
VCC = 3V
70
10
15
20
5
EFFICIENCY vs. LOAD CURRENT
WITH MAX1554 DRIVING 9 WHITE LEDS
L1 = 47µH
4700pF ACROSS LEDs
VCC = 4V
80
VCC = 3.6V
70
20
15
0
LED CURRENT
vs. INPUT VOLTAGE
20
L1 = 47µH,
4700pF ACROSS LEDs
17
26
23
L1 = 22µH, NO CAPACITOR ACROSS LEDs
20
L1 = 47µH,
4700pF ACROSS LEDs
17
L1 = 33µH, 4700pF ACROSS LEDs
14
R1 = 10Ω, VBRT = 1.25V
CIRCUIT OF FIGURE 3
R1 = 14Ω, VBRT = 3.3V
11
0
5
10
15
11
2.5
20
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
LOAD CURRENT (mA)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
LED CURRENT vs. INPUT VOLTAGE
WITH MAX1554 DRIVING 9 LEDS
LED CURRENT
vs. BRT VOLTAGE
LED CURRENT
vs. BRT DUTY CYCLE
17
25
LED CURRENT (mA)
20
25
20
15
5.5
MAX1553/54 toc09
30
LED CURRENT (mA)
23
5.0
30
MAX1553/54 toc08
35
MAX1553/54 toc07
26
20
15
LED CURRENT
vs. INPUT VOLTAGE
L1 = 33µH, 4700pF ACROSS LEDs
50
10
LOAD CURRENT (mA)
14
60
5
LOAD CURRENT (mA)
L1 = 22µH, NO CAPACITOR ACROSS LEDs
23
LED CURRENT (mA)
VCC = 5V
10
26
MAX1553/54 toc04
100
VCC = 3V
70
50
0
LOAD CURRENT (mA)
90
VCC = 3.6V
60
LED CURRENT (mA)
5
80
L1 = 33µH
4700pF ACROSS LEDs
50
0
EFFICIENCY (%)
90
60
L1 = 22µH
NO CAPACITOR ACROSS LEDs
50
MAX1553/54 toc03
90
VCC = 5V
VCC = 4V
MAX1553/54 toc06
80
100
MAX1553/54 toc02
VCC = 4V
VCC = 5V
VCC = 4V
EFFICIENCY vs. LOAD CURRENT
DRIVING 6 WHITE LEDS
MAX1553/54 toc05
EFFICIENCY (%)
90
100
EFFICIENCY (%)
VCC = 5V
MAX1553/54 toc01
100
EFFICIENCY vs. LOAD CURRENT
DRIVING 6 WHITE LEDS
EFFICIENCY (%)
EFFICIENCY vs. LOAD CURRENT
DRIVING 6 WHITE LEDS
LED CURRENT (mA)
MAX1553/MAX1554
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
20
15
10
10
14
5
5
CIRCUIT OF FIGURE 3
11
3.5
4.0
4.5
INPUT VOLTAGE (V)
4
0
0
3.0
5.0
5.5
0
0.6
1.2
1.8
2.4
BRT VOLTAGE (V)
3.0
3.6
0
20
40
60
BRT DUTY CYCLE (%)
_______________________________________________________________________________________
80
100
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
SWITCHING WAVEFORMS
(DISCONTINUOUS OPERATION,
3.75V Li+ BATTERY, 10mA OUTPUT)
SWITCHING WAVEFORMS
(CONTINUOUS OPERATION,
3.75V Li+ BATTERY, 18mA OUTPUT)
MAX1553/54 toc10
VLX
MAX1553/54 toc11
10V/div
VLX
10V/div
VOUT
200mV/div
VOUT
200mV/div
IL
200mA/div
IL
200mA/div
2µs/div
2µs/div
L1 = 47µH, 4700pF CAPACITOR ACROSS LEDs
L1 = 47µH, 4700pF CAPACITOR ACROSS LEDs
STARTUP/SHUTDOWN WAVEFORMS
BRT STEP RESPONSE
MAX1553/54 toc12
VEN
MAX1553/54 toc13
5V/div
VFB
200mV/div
VBRT
1V/div
VFB
200mV/div
VOUT
VOUT
2V/div
10V/div
40ms/div
L1 = 22µH
20ms/div
L1 = 22µH,
VBRT = 0.5V TO 1.25V TO O.5V
_______________________________________________________________________________________
5
MAX1553/MAX1554
Typical Operating Characteristics (continued)
(MAX1553 driving six white LEDs, VCC = VEN = 3.6V, Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
MAX1553/MAX1554
Pin Description
PIN
NAME
FUNCTION
1
GND
Ground
2
VCC
Voltage-Supply Input. 2.7V to 5.5V. The IC is powered from VCC.
3
EN
Enable Input. Drive high or connect to VCC to enable the IC. Drive EN low for shutdown.
4
BRT
Brightness-Control Input. Either an analog or PWM control signal can be used. The LED current can be
controlled over a 10 to 1 range. The PWM signal must be between 100Hz and 10kHz, and must have an
amplitude greater than 1.72V.
5
FB
Feedback Input. Connect to the cathode of the LED string and connect a resistor from FB to GND to set the
LED current.
6
SS
Soft-Start Timing-Control Input. Connect a capacitor from SS to GND to control soft-start timing. See the SoftStart section for information on selecting the soft-start capacitor. SS is pulled to ground with an internal 200Ω
switch when EN is low.
7
OV
Overvoltage Sense. Connect to a resistor-divider from the anode of the LED string to set the overvoltage
threshold. See Figures 1, 2, and 3.
8
LX
Inductor Connection. Connect to the inductor and diode. LX is high impedance when EN is low.
—
EP
Exposed Pad. Connect to GND.
Detailed Description
Control Scheme
The MAX1553/MAX1554 utilize a minimum off-time, current-limited control scheme. If the voltage at FB drops
below the regulation threshold, the internal low-side
MOSFET turns on and the inductor current ramps up to
the current limit. Once the current-limit comparator
trips, the low-side MOSFET turns off for the minimum
off-time (250ns). After 250ns, if the voltage at FB is
above the regulation threshold, the low-side MOSFET
stays off. If the voltage at FB is below the regulation
point, the low-side MOSFET turns back on and the
cycle repeats. By using a regulation control scheme
that is not fixed frequency and that can skip pulses, the
MAX1553/MAX1554 operate with very high efficiency.
Soft-Start
Soft-start is provided on the MAX1553/MAX1554 to minimize inrush current. The soft-start time is set with an
external capacitor, C3 (Figures 1, 2, and 3). Use the following equation to solve for C3:
C3 =
tSS
Shutdown
The MAX1553/MAX1554 feature a low-current shutdown feature. When EN is low, the IC turns off, reducing its supply current to approximately 0.1µA. For
normal operation, drive EN high or connect to VCC.
Overvoltage Protection
The MAX1553/MAX1554 have an adjustable overvoltageprotection circuit. When the voltage at OV reaches the
overvoltage threshold (1.25V typ), the protection circuitry
prevents the internal MOSFET from switching, allowing
the output voltage to decay.
The peak output voltage in an overvoltage-protection
event is set with a resistor-divider from the output connected to OV (R2 and R3 in Figures 1, 2, and 3). Select
a value for R3 (10kΩ is recommended), then solve for
R2 using the following equation:
V

R2 = R3 x  OUT(PEAK) − 1


VOV
where VOV is the overvoltage threshold (1.25V typ), and
VOUT(PEAK) is the desired peak output voltage.
2 x 105
where tSS is the soft-start time. A value of 0.1µF provides a soft-start time of 20ms.
6
_______________________________________________________________________________________
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
VCC
LX
ENABLE
CONTROL
CIRCUITRY
EN
CONTROL
LOGIC
DRIVER
CURRENT
LIMIT
GND
UVLO
VLIM
1.25V
BANDGAP
REFERENCE
REF
MINIMUM
tOFF ONE-SHOT
MINIMUM
tON ONE-SHOT
BIAS
GENERATOR
ERROR
COMPARATOR
FB
OV
COMPARATOR
OV
67kΩ
MAX1553
MAX1554
REF
128kΩ
1.72V
BRT
206kΩ
SS
L1
47µH
TOKO A920CY-470M
2.7V TO 5.5V
INPUT
C1
4.7µF
ON
OFF
VCC
LX
EN
OV
D1
CMDSH2-3
C2
0.47µF
25V
PWM
OR
DC CONTROL
BRT
C3
0.1µF
SS
2.7V TO 5.5V
INPUT
C1
10µF
R2
200kΩ
C4
4700pF
R3
10kΩ
MAX1553
ON
OFF
D2–D7
WHITE
LEDs
R1
10Ω
Figure 1. Circuit with the MAX1553 Driving Six White LEDs
VCC
LX
EN
OV
D1
CMDSH1-60M
C2
0.47µF
50V
R2
330kΩ
C4
3300pF
R3
10kΩ
MAX1553
PWM
OR
DC CONTROL
FB
GND
L1
4.7µH
MURATA LQH32C
BRT
C3
0.1µF
SS
D2–D10
WHITE
LEDs
FB
GND
R1
10Ω
Figure 2. Circuit with the MAX1553 Driving Nine White LEDs at
Up to 15mA
_______________________________________________________________________________________
7
MAX1553/MAX1554
Functional Diagram
MAX1553/MAX1554
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
Adjusting the LED Current
Adjusting the output current changes the brightness of
the LEDs. The LED current is set by the voltage at BRT
(VBRT) and the sense resistor (R1) at FB. The VBRT
range for adjusting output current is 0 to 1.25V. Over
this range, the LED current is found from the following
equation:
ILED =
VBRT + 0.17
6.67 x R1
BRT can be overdriven; however, applying a V BRT
greater than 1.72V does not increase the output current
above the level at 1.72V. See the LED Current vs. BRT
Voltage graph in the Typical Operating Characteristics
section. To set the maximum LED current, calculate R1
when VBRT is at its maximum, as follows:
R1 =
VBRT(MAX) + 0.17
6.67 x ILED(MAX)
where VBRT(MAX) is 1.72V if BRT is connected to any
value greater than 1.72V, such as V CC . Otherwise,
VBRT(MAX) is the maximum applied BRT control voltage. Power dissipation in R1 is typically less than 5mW;
therefore, power dissipation in a standard chip resistor
is not a concern.
PWM Dimming Control
The BRT input is also used as a digital input allowing
LED brightness control with a logic-level PWM signal
applied directly to BRT. The frequency range is from
100Hz to 10kHz, and the duty cycle range is 0 to 100%.
A 0% duty cycle corresponds to the minimum current,
and a 100% duty cycle corresponds to full current. See
the LED Current vs. BRT Duty Cycle graph in the
Typical Operating Characteristics section. The BRT
resistor and SS capacitor form a lowpass filter, so PWM
dimming results in DC current to the LEDs without the
need for additional RC filters.
Capacitor Selection
A 0.47µF ceramic output capacitor (C2) is recommended for most applications. For circuits driving six or
fewer LEDs, use a 4.7µF ceramic input capacitor (C1).
For circuits driving more than six LEDs, use a 10µF
input capacitor (C1). For best stability over a wide temperature range, use capacitors with an X5R, X7R, or
better dielectric.
8
L1
22µH
A915BY-220M
3.15V TO 5.5V
INPUT
C1
10µF
ON
OFF
VCC
LX
EN
OV
D1
CMDSH1-60M
C2
0.47µF
50V
R2
330kΩ
C4
3300pF
R3
10kΩ
MAX1554
PWM
OR
DC CONTROL
BRT
C3
0.1µF
SS
D2–D11
WHITE
LEDs
FB
GND
R1
10Ω
Figure 3. Circuit with the MAX1554 Driving 10 White LEDs
Inductor Selection
The MAX1553 has a 480mA inductor current limit and
can drive up to six LEDs at 20mA or nine LEDs at
15mA. Inductor values from 4.7µH to 47µH work satisfactorily. Larger values provide the best efficiency while
small inductor values allow the smallest inductor size. A
good choice for best efficiency is the TOKO D62 or
D62L series at 47µH. For smallest size, the Murata
LQH32C at 4.7µH works well.
The MAX1554 has a 970mA inductor current limit and
can drive up to 10 LEDs at 20mA. Inductor values from
4.7µH to 22µH work satisfactorily. A good choice for
high efficiency and small size when driving 9 or 10
LEDs is the TOKO D62 series at 22µH.
When large inductor values are used to optimize efficiency, the MAX1553/MAX1554 operate with continuous
inductor current. With large inductor values (typically
greater than 10µH), stability, input, and output ripple
are improved by connecting a capacitor in parallel with
the LEDs (C4 in Figures 1, 2, and 3).
To prevent saturation, use an inductor with a current
rating that matches the device’s LX current limit.
However, if size is particularly important, it is sometimes acceptable to operate the inductor 10% into saturation. For best efficiency, the inductor’s DC resistance
should also be as low as possible.
Diode Selection
The MAX1553/MAX1554s’ high switching frequency
demands a high-speed rectification diode (D1) for optimum efficiency. A Schottky diode is recommended due
to its fast recovery time and low forward-voltage drop.
_______________________________________________________________________________________
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
SUPPLIER
PHONE
WEBSITE
Central
Semiconductor
631-435-1110
www.centralsemi.com
Kamaya
260-489-1533
www.kamaya.com
Murata
814-237-1431
www.murata.com
Nichia
248-352-6575
www.nichia.com
Panasonic
714-373-7939
www.panasonic.com
Sumida
847-956-0666
www.sumida.com
Taiyo Yuden
408-573-4150
www.t-yuden.com
TDK
847-803-6100
www.component.tdk.com
TOKO
847-297-0070
www.toko.com
Ensure the diode’s average and peak current ratings
exceed the average output current and peak inductor
current. In addition, the diode’s reverse breakdown
voltage must exceed VOUT.
Applications Information
Low Input-Voltage Applications
The MAX1553/MAX1554 have minimum input voltages
of 2.7V (MAX1553) and 3.15V (MAX1554). However,
lower battery voltages can still be boosted for LED
drive as long as V CC remains within the operating
range. Since most systems have a 3.3V system supply
active when the display is active and backlit, that logic
supply can be used to supply VCC, while the battery
power connects directly to the boost inductor. No battery current is drawn when EN is low (Figure 4).
BATTERY
INPUT
C1
4.7µF
L1
3.3V
LOGIC
C4
0.1µF
ON
OFF
D1
LX
VCC
EN
R2
OV
R3
MAX1553
MAX1554
C3
0.1µF
SS
WHITE
LEDs
FB
BRT
GND
R1
Figure 4. The MAX1553/MAX1554 can drive LEDs from battery
voltages that are lower than the device operating voltage
range by powering VCC from a logic supply and connecting
the boost inductor to the battery.
When laying out a board, minimize trace lengths
between the IC and the inductor, diode, input capacitor, output capacitor, and R1. Keep traces short, direct,
and wide. Keep noisy traces, such as the LX node
trace, away from FB. Place the VCC bypass capacitor
(C1) as close to the IC as possible. The ground connections of C1 and C2 should be as close together as
possible. Star connect the grounds for R1, R3, C3, and
the BRT voltage supply as close to the IC as possible.
The traces from VCC to C1, from C2 to the LEDs, and
from the LEDs to R1 can be longer if required.
PC Board Layout
Due to fast-switching waveforms and high-current
paths, careful PC board layout is required. An evaluation kit (MAX1553EVKIT) is available as an example of
a proper layout.
C2
0.47µF
Chip Information
TRANSISTOR COUNT: 740
PROCESS: BiCMOS
_______________________________________________________________________________________
9
MAX1553/MAX1554
Table 1. Component Suppliers
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.
6, 8, &10L, QFN THIN.EPS
MAX1553/MAX1554
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
L
A
D
D2
A2
PIN 1 ID
1
N
1
C0.35
b
E
PIN 1
INDEX
AREA
[(N/2)-1] x e
REF.
E2
DETAIL A
e
k
A1
CL
CL
L
L
e
e
A
DALLAS
SEMICONDUCTOR
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 6, 8 & 10L,
TDFN, EXPOSED PAD, 3x3x0.80 mm
NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY
APPROVAL
DOCUMENT CONTROL NO.
21-0137
10
______________________________________________________________________________________
REV.
D
1
2
High-Efficiency, 40V Step-Up
Converters for 2 to 10 White LEDs
COMMON DIMENSIONS
SYMBOL
A
MIN.
MAX.
0.70
0.80
D
2.90
3.10
E
2.90
3.10
A1
0.00
0.05
L
k
0.20
0.40
0.25 MIN.
A2
0.20 REF.
PACKAGE VARIATIONS
PKG. CODE
N
D2
E2
e
JEDEC SPEC
b
T633-1
6
1.50–0.10
2.30–0.10
0.95 BSC
MO229 / WEEA
0.40–0.05
1.90 REF
T833-1
8
1.50–0.10
2.30–0.10
0.65 BSC
MO229 / WEEC
0.30–0.05
1.95 REF
T1033-1
10
1.50–0.10
2.30–0.10
0.50 BSC
MO229 / WEED-3
0.25–0.05
2.00 REF
[(N/2)-1] x e
DALLAS
SEMICONDUCTOR
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 6, 8 & 10L,
TDFN, EXPOSED PAD, 3x3x0.80 mm
APPROVAL
DOCUMENT CONTROL NO.
21-0137
REV.
D
2
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX1553/MAX1554
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.