© Semiconductor Components Industries, LLC, 2010
February, 2010 Rev. 1
1Publication Order Number:
CAT4139/D
CAT4139
22 V High Current Boost
White LED Driver
Description
The CAT4139 is a DC/DC stepup converter that delivers an
accurate constant current ideal for driving LEDs. Operation at a fixed
switching frequency of 1 MHz allows the device to be used with small
value external ceramic capacitors and inductor. LEDs connected in
series are driven with a regulated current set by the external resistor
R1. The CAT4139 is ideal for driving parallel strings of up to five
white LEDs in series or up to 22 V.
LED dimming can be done by using a DC voltage, a logic signal, or
a pulse width modulation (PWM) signal. The shutdown input pin
allows the device to be placed in powerdown mode with “zero”
quiescent current.
In addition to thermal protection and overload current limiting, the
device also enters a very low power operating mode during “Open
LED” fault conditions. The device is housed in a low profile (1 mm
max height) 5lead TSOT23 package for space critical applications.
Features
Switch Current Limit 750 mA
Drives LED Strings up to 22 V
Up to 87% Efficiency
Low Quiescent Ground Current 0.6 mA
1 MHz Fixed Frequency Low Noise Operation
Soft Start “Inrush” Current Limiting
Shutdown Current Less than 1 mA
Open LED Overvoltage Protection
Automatic Shutdown at 1.9 V (UVLO)
Thermal Overload Protection
TSOT23 5Lead (1 mm Max Height)
These Devices are PbFree, Halogen Free/BFR Free and are RoHS
Compliant
Applications
GPS Navigation Systems
Portable Media Players
Handheld Devices
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TSOT23
TD SUFFIX
CASE 419AE
PIN CONNECTIONS
MARKING DIAGRAM
Device Package Shipping
ORDERING INFORMATION
CAT4139TDGT3
(Note 1)
TSOT23
(PbFree)
3,000/
Tape & Reel
TP = Specific Device Code
Y = Production Year (Last Digit)
M = Production Month (19, A, B, C)
1
5
(Top View)
VIN
SHDN
SW
GND
FB
1
TPYM
1. NiPdAu Plated Finish (RoHScompliant)
CAT4139
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Figure 1. Typical Application Circuit
VIN
CAT4139
LD 9 strings at
20 mA
R1
1.62 W
R2 180 mA
(300 mV)
4.7 mF
5 V
C1
1 mF
35 V
C2
FB
SW
GND
ON
22 mH
OFF
1 kW
SHDN
VIN
IOUT
VOUT
L: Sumida CDRH6D28220
D: Central CMSH140 (rated 40 V)
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameters Ratings Units
VIN, FB Voltage 0.3 to +7 V
SHDN Voltage 0.3 to +7 V
SW Voltage 0.3 to +40 V
Storage Temperature Range 65 to +160 _C
Junction Temperature Range 40 to +150 _C
Lead Temperature 300 _C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
Table 2. RECOMMENDED OPERATING CONDITIONS (Typical application circuit with external components is shown above.)
Parameters Range Units
VIN up to 5.5 V
SW pin voltage 0 to 22 V
Ambient Temperature Range (Note 2) 40 to +85 _C
2. TSOT235 package thermal resistance qJA = 135°C/W when mounted on board over a ground plane.
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Table 3. DC ELECTRICAL CHARACTERISTICS
(VIN = 3.6 V, ambient temperature of 25°C (over recommended operating conditions unless otherwise specified))
Symbol Parameter Test Conditions Min Typ Max Units
IQOperating Current VFB = 0.2 V
VFB = 0.4 V (not switching)
0.6
0.1
1.5
0.6
mA
ISD Shutdown Current VSHDN = 0 V 0.1 1 mA
VFB FB Pin Voltage 9 x 3 LEDs, IOUT = 180 mA 285 300 315 mV
IFB FB pin input leakage 1mA
ILED Programmed LED Current R1 = 10 W
R1 = 3 W
28.5 30
100
31.5 mA
VIH
VIL
SHDN Logic High
SHDN Logic Low
Enable Threshold Level
Shutdown Threshold Level 0.4
0.8
0.7
1.5 V
FSW Switching Frequency 0.8 1.0 1.3 MHz
ILIM Switch Current Limit VIN = 3.6 V
VIN = 5 V
600
750
mA
RSW Switch “On” Resistance ISW = 100 mA 1.0 2.0 W
ILEAK Switch Leakage Current Switch Off, VSW = 5 V 1 5 mA
TSD Thermal Shutdown 150 °C
THYST Thermal Hysteresis 20 °C
VUVLO Undervoltage lock out (UVLO) Threshold 1.9 V
VOVDET Overvoltage detection threshold 23 24 V
VOCL Output Clamp voltage “Open LED” 29 V
DC Maximum duty cycle
Minimum duty cycle
92
16
%
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TYPICAL CHARACTERISTICS
(VIN = 5.0 V, IOUT = 180 mA, TAMB = 25°C, with typical application circuit unless otherwise specified.)
Figure 2. Quiescent Current vs. VIN
(Not Switching)
Figure 3. Quiescent Current vs. VIN
(Switching)
INPUT VOLTAGE (V) INPUT VOLTAGE (V)
5.04.54.03.53.0
50
100
150
200
5.04.54.03.53.0
0
0.5
1.0
1.5
2.0
Figure 4. FB Pin Voltage vs. Temperature Figure 5. FB Pin Voltage vs. Output Current
TEMPERATURE (°C) OUTPUT CURRENT (mA)
100 15050050
297
298
301
302
303
20018016014012010080
290
295
300
305
310
Figure 6. Switching Frequency vs. Supply
Voltage
Figure 7. Switch ON Resistance vs.
Input Voltage
INPUT VOLTAGE (V)
4.0 4.53.53.0
0.8
0.9
1.0
1.1
1.2
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
FB PIN VOLTAGE (mV)
FB PIN VOLTAGE (mV)
SWITCHING FREQUENCY (MHz)
VFB = 0.4 V
INPUT VOLTAGE (V)
4.54.0 5.03.53.0
0
0.5
1.0
1.5
2.0
SWITCH RESISTANCE (W)
5.5 5.5
299
300
5.0 5.5 5.5
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TYPICAL CHARACTERISTICS
(VIN = 5.0 V, IOUT = 180 mA, TAMB = 25°C, with typical application circuit unless otherwise specified.)
Figure 8. Output Current vs. Input Voltage Figure 9. Output Current Regulation
INPUT VOLTAGE (V) INPUT VOLTAGE (V)
5.04.54.03.53.0
100
120
140
160
180
200
5.55.14.94.74.5
2.0
0.5
0
0.5
2.0
Figure 10. Efficiency vs. Output Current Figure 11. Efficiency vs. Input Voltage
OUTPUT CURRENT (mA) INPUT VOLTAGE (V)
20018016012010080
75
80
85
90
95
5.55.14.74.5
75
80
85
90
95
Figure 12. Powerup at 180 mA Figure 13. Switching Waveform
LED CURRENT (mA)
IOUT VARIATION (%)
EFFICIENCY (%)
EFFICIENCY (%)
5.3
140
IOUT = 120 mA
4.9 5.3
5.5
1.0
1.5
1.0
1.5
IOUT = 180 mA
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TYPICAL CHARACTERISTICS
(VIN = 5.0 V, IOUT = 180 mA, TAMB = 25°C, with typical application circuit unless otherwise specified.)
Figure 14. Maximum Output Current Figure 15. Shutdown Voltage
INPUT VOLTAGE (V) INPUT VOLTAGE (V)
5.04.54.03.53.0
0
50
100
150
250
300
5.04.03.53.0
0.2
0.6
1.0
Figure 16. Switch Current Limit
INPUT VOLTAGE (V)
5.55.35.14.74.5
600
650
750
800
900
MAX OUTPUT CURRENT (mA)
SHUTDOWN VOLTAGE (V)
SWITCH CURRENT LIMIT (mA)
4.5
4.9
5.5
0.4
0.8 40°C
25°C
85°C
125°C
200
VOUT = 14 V
VOUT = 9 V
VOUT = 12 V
VOUT = 9 V
700
850
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Pin Description
VIN is the supply input for the internal logic. The device is
compatible with supply voltages down to 2.8 V and up to
5.5 V. It is recommended that a small bypass ceramic
capacitor (4.7 mF) be placed between the VIN and GND pins
near the device. If the supply voltage drops below 1.9 V, the
device stops switching.
SHDN is the shutdown logic input. When the pin is tied to
a voltage lower than 0.4 V, the device is in shutdown mode,
drawing nearly zero current. When the pin is connected to a
voltage higher than 1.5 V, the device is enabled.
GND is the ground reference pin. This pin should be
connected directly to the ground plane on the PCB.
SW pin is connected to the drain of the internal CMOS
power switch of the boost converter. The inductor and the
Schottky diode anode should be connected to the SW pin.
Traces going to the SW pin should be as short as possible
with minimum loop area. An overvoltage detection circuit
is connected to the SW pin. When the voltage reaches 24 V,
the device enters a low power operating mode preventing the
SW voltage from exceeding the maximum rating.
FB feedback pin is regulated at 0.3 V. A resistor connected
between the FB pin and ground sets the LED current
according to the formula:
ILED +
0.3 V
R1
The lower LED cathode is connected to the FB pin.
Table 4. PIN DESCRIPTIONS
Pin # Name Function
1 SW Switch pin. This is the drain of the internal power switch.
2 GND Ground pin. Connect the pin to the ground plane.
3 FB Feedback pin. Connect to the last LED cathode.
4 SHDN Shutdown pin (Logic Low). Set high to enable the driver.
5 VIN Power Supply input.
Figure 17. Simplified Block Diagram
VOUT
Current
Sense
Ref
300 mV
C1
Thermal
Shutdown
& UVLO
1 MHz
Oscillator
Over Voltage
Protection
PWM
&
Logic
Driver
C2
GND
SW
FB
+
+
+
VIN
VIN
SHDN
ILED
RS
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Device Operation
The CAT4139 is a fixed frequency (1 MHz), low noise,
inductive boost converter that provides a constant current
with excellent line and load regulation. The device uses a
highvoltage CMOS power switch between the SW pin and
ground to energize the inductor. When the switch is turned
off, the stored energy in the inductor is released into the load
via the Schottky diode.
The on/off duty cycle of the power switch is internally
adjusted and controlled to maintain a constant regulated
voltage of 0.3 V across the feedback resistor connected to the
feedback pin (FB). The value of the resistor sets the LED
current accordingly (0.3 V/R1).
During the initial powerup stage, the duty cycle of the
internal power switch is limited to prevent excessive inrush
currents and thereby provide a “softstart” mode of
operation.
In the event of an “Open LED” fault condition, where the
feedback control loop becomes open, the output voltage will
continue to increase. Once this voltage exceeds 24 V, an
internal protection circuit will become active and place the
device into a very low power safe operating mode.
Thermal overload protection circuitry has been included
to prevent the device from operating at unsafe junction
temperatures above 150°C. In the event of a thermal
overload condition the device will automatically shutdown
and wait till the junction temperatures cools to 130°C before
normal operation is resumed.
Application Information
External Component Selection
Capacitors
The CAT4139 only requires small ceramic capacitors of
4.7 mF on the input and 1 mF on the output. Under normal
condition, a 4.7 mF input capacitor is sufficient. For
applications with higher output power, a larger input
capacitor of 10 mF may be appropriate. X5R and X7R
capacitor types are ideal due to their stability across
temperature range.
Inductor
A 22 mH inductor is recommended for most of the
CAT4139 applications. In cases where the efficiency is
critical, inductances with lower series resistance are
preferred. Inductors with current rating of 800 mA or higher
are recommended for most applications. Sumida
CDRH6D28220 22 mH inductor has a rated current of
1.2 A and a series resistance (D.C.R.) of 128 mW typical.
Schottky Diode
The current rating of the Schottky diode must exceed the
peak current flowing through it. The Schottky diode
performance is rated in terms of its forward voltage at a
given current. In order to achieve the best efficiency, this
forward voltage should be as low as possible. The response
time is also critical since the driver is operating at 1 MHz.
Central Semiconductor Schottky rectifier CMSH140 (1 A
rated) is recommended for most applications.
LED Current Setting
The LED current is set by the external resistor R1
connected between the feedback pin (FB) and ground. The
formula below gives the relationship between the resistor
and the current:
R1 +
0.3 V
LED current
Table 5. RESISTOR R1 AND LED CURRENT
LED Current (mA) R1 (W)
20 15
25 12
30 10
100 3
300 1
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Open LED Protection
In the event of an “Open LED” fault condition, the
CAT4139 will continue to boost the output voltage with
maximum power until the output voltage reaches
approximately 24 V. Once the output exceeds this level, the
internal circuitry immediately places the device into a very
low power mode where the total input power is limited to
about 6 mW (about 1.6 mA input current with a 3.6 V
supply). The SW pin clamps at a voltage below its maximum
rating of 40 V. There is no need to use an external zener diode
between VOUT and the FB pin. A 35 V rated C2 capacitor
is required to prevent any overvoltage damage in the open
LED condition.
Figure 18. Open LED Protection Circuit
VIN
CAT4139
L
Schottky 40 V
(Central CMSH054)
D
4.7 mF
C1
1 mF
C2
R1
15 W
FB
SW
GND
ON
22 mH
OFF
VIN
VOUT
SHDN
Figure 19. Open LED Disconnect and Reconnect Figure 20. Open LED Disconnect
Figure 21. Open LED Supply Current Figure 22. Open LED Output Voltage
INPUT VOLTAGE (V) INPUT VOLTAGE (V)
5.55.04.54.03.53.0
1.0
1.5
2.0
2.5
5.55.04.54.03.53.0
15
20
25
30
35
INPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
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Dimming Control
There are several methods available to control the LED
brightness.
PWM Signal on the SHDN Pin
LED brightness dimming can be done by applying a PWM
signal to the SHDN input. The LED current is repetitively
turned on and off, so that the average current is proportional
to the duty cycle. A 100% duty cycle, with SHDN always
high, corresponds to the LEDs at nominal current. Figure 23
shows a 1 kHz signal with a 50% duty cycle applied to the
SHDN pin. The recommended PWM frequency range is from
100 Hz to 2 kHz.
Figure 23. Switching Waveform with 1 kHz
PWM on SHDN
Filtered PWM Signal
A filtered PWM signal used as a variable DC voltage can
control the LED current. Figure 24 shows the PWM control
circuitry connected to the CAT4139 FB pin. The PWM
signal has a voltage swing of 0 V to 2.5 V. The LED current
can be dimmed within a range from 0 mA to 20 mA. The
PWM signal frequency can vary from very low frequency
and up to 100 kHz.
Figure 24. Circuit for Filtered PWM Signal
VIN SW
CAT4139
0 V
2.5 V
R1
15 W
R2
1 kW
3.1 kW
3.73 kW
C3
0.22 mF
LED
Current
PWM
Signal
FBGND
RA
SHDN
VIN RBVFB = 300 mV
A PWM signal at 0 V DC, or a 0% duty cycle, results in
a max LED current of about 22 mA. A PWM signal with a
93% duty cycle or more, results in an LED current of 0 mA.
Figure 25. Filtered PWM Dimming (0 V to 2.5 V)
LED CURRENT (mA)
25
20
15
10
5
0
0 102030405060708090100
PWM DUTY CYCLE (%)
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Board Layout
The CAT4139 is a high-frequency switching regulator.
The traces that carry the high-frequency switching current
have to be carefully laid out on the board in order to
minimize EMI, ripple and noise in general. The thicker lines
on Figure 26 show the switching current path. All these
traces have to be short and wide enough to minimize the
parasitic inductance and resistance. The loop shown on
Figure 26 corresponds to the current path when the
CAT4139 internal switch is closed. On Figure 27 is shown
the current loop, when the CAT4139 switch is open. Both
loop areas should be as small as possible.
Capacitor C1 has to be placed as close as possible to the
VIN pin and GND. The capacitor C2 has to be connected
separately to the top LED anode. A ground plane under the
CAT4139 allows for direct connection of the capacitors to
ground. The resistor R1 must be connected directly to the
GND pin of the CAT4139 and not shared with the switching
current loops and any other components.
Figure 26. Closedswitch Current Loop Figure 27. Openswitch Current Loop
VIN
CAT4139
LDV
OUT
R1
FB
Switch
Closed
SW
GND
VIN
CAT4139
LD
R1
FB
Switch
Open
SW
GND
SHDN
C1C2
VIN
C2
C1
SHDN
VIN
VOUT
Figure 28. Recommended PCB Layout
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PACKAGE DIMENSIONS
TSOT23, 5 LEAD
CASE 419AE01
ISSUE O
E1 E
A2
A1
e
b
D
c
A
TOP VIEW
SIDE VIEW END VIEW
L1
LL2
Notes:
(1) All dimensions are in millimeters. Angles in degrees.
(2) Complies with JEDEC MO-193.
SYMBOL
θ
MIN NOM MAX
q
A
A1
A2
b
c
D
E
E1
e
L
L1
L2
0.01
0.80
0.30
0.12
0.30
0.05
0.87
0.15
2.90 BSC
2.80 BSC
1.60 BSC
0.95 TYP
0.40
0.60 REF
0.25 BSC
1.00
0.10
0.90
0.45
0.20
0.50
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Example of Ordering Information (Note 5)
Prefix Device # Suffix
Company ID
CAT 4139
Product Number
4139
T3
T: Tape & Reel
3: 3,000 / Reel
Tape & Reel (Note 7)
(Optional)
TD
Package
TD: TSOT23
G
G: NiPdAu
Lead Finish
SERIES LED DRIVERS
Part Number Description
ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
CAT4137
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
CMOS Boost Converter White LED Driver
ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
CAT4237
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
High Voltage CMOS Boost White LED Driver
ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
CAT4238
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
High Efficiency 10 LED Boost Converter
ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
CAT4139
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
22 V High Current Boost White LED Driver
ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
CAT4240
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
6 Watt Boost LED Driver
3. All packages are RoHScompliant (Leadfree, Halogenfree).
4. The standard lead finish is NiPdAu.
5. The device used in the above example is a CAT4139TDGT3 (TSOT23, NiPdAu, Tape & Reel, 3,000/Reel).
6. For additional package and temperature options, please contact your nearest ON Semiconductor Sales office.
7. For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
CAT4139/D
PUBLICATION ORDERING INFORMATION
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USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
Japan Customer Focus Center
Phone: 81357733850
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