CAT4139TD-GT3 - ON SEMICONDUCTOR

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 step−up 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 power−down 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) 5−lead TSOT−23 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 “In−rush” Current Limiting

•Shutdown Current Less than 1 mA

•Open LED Overvoltage Protection

•Automatic Shutdown at 1.9 V (UVLO)

•Thermal Overload Protection

•TSOT−23 5−Lead (1 mm Max Height)

•These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS

Compliant

Applications

•GPS Navigation Systems

•Portable Media Players

•Handheld Devices

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TSOT−23

TD SUFFIX

CASE 419AE

PIN CONNECTIONS

MARKING DIAGRAM

Device Package Shipping

ORDERING INFORMATION

CAT4139TD−GT3

(Note 1)

TSOT−23

(Pb−Free)

3,000/

Tape & Reel

TP = Specific Device Code

Y = Production Year (Last Digit)

M = Production Month (1−9, A, B, C)

(Top View)

VIN

SHDN

GND

TPYM

1. NiPdAu Plated Finish (RoHS−compliant)

CAT4139

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Figure 1. Typical Application Circuit

VIN

CAT4139

LD 9 strings at

20 mA

1.62 W

R2 180 mA

(300 mV)

4.7 mF

5 V

1 mF

35 V

GND

22 mH

OFF

1 kW

SHDN

VIN

IOUT

VOUT

L: Sumida CDRH6D28−220

D: Central CMSH1−40 (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. TSOT23−5 package thermal resistance qJA = 135°C/W when mounted on board over a ground plane.

CAT4139

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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

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

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 Under−voltage lock out (UVLO) Threshold 1.9 V

VOV−DET Over−voltage detection threshold 23 24 V

VOCL Output Clamp voltage “Open LED” 29 V

DC Maximum duty cycle

Minimum duty cycle

CAT4139

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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

100

150

200

5.04.54.03.53.0

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 150500−50

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)

FB PIN VOLTAGE (mV)

SWITCHING FREQUENCY (MHz)

VFB = 0.4 V

INPUT VOLTAGE (V)

4.54.0 5.03.53.0

0.5

1.0

1.5

2.0

SWITCH RESISTANCE (W)

5.5 5.5

299

300

5.0 5.5 5.5

CAT4139

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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

0.5

2.0

Figure 10. Efficiency vs. Output Current Figure 11. Efficiency vs. Input Voltage

OUTPUT CURRENT (mA) INPUT VOLTAGE (V)

20018016012010080

5.55.14.74.5

Figure 12. Power−up at 180 mA Figure 13. Switching Waveform

LED CURRENT (mA)

IOUT VARIATION (%)

EFFICIENCY (%)

5.3

140

IOUT = 120 mA

4.9 5.3

5.5

−1.0

−1.5

1.0

1.5

IOUT = 180 mA

CAT4139

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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

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

CAT4139

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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 over−voltage 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

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

Thermal

Shutdown

& UVLO

1 MHz

Oscillator

Over Voltage

Protection

PWM

Logic

Driver

GND

–

VIN

SHDN

ILED

CAT4139

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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

high−voltage 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 power−up stage, the duty cycle of the

internal power switch is limited to prevent excessive in−rush

currents and thereby provide a “soft−start” 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

CDRH6D28−220 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 CMSH1−40 (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

CAT4139

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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

Schottky 40 V

(Central CMSH05−4)

4.7 mF

1 mF

15 W

GND

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

INPUT CURRENT (mA)

OUTPUT VOLTAGE (V)

CAT4139

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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

15 W

1 kW

3.1 kW

3.73 kW

0.22 mF

LED

Current

PWM

Signal

FBGND

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)

0 102030405060708090100

PWM DUTY CYCLE (%)

CAT4139

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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. Closed−switch Current Loop Figure 27. Open−switch Current Loop

VIN

CAT4139

LDV

OUT

Switch

Closed

GND

VIN

CAT4139

Switch

Open

GND

SHDN

C1C2

VIN

SHDN

VIN

VOUT

Figure 28. Recommended PCB Layout

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PACKAGE DIMENSIONS

TSOT−23, 5 LEAD

CASE 419AE−01

ISSUE O

E1 E

TOP VIEW

SIDE VIEW END VIEW

LL2

Notes:

(1) All dimensions are in millimeters. Angles in degrees.

(2) Complies with JEDEC MO-193.

SYMBOL

MIN NOM MAX

0º 8º

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

CAT4139

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Example of Ordering Information (Note 5)

Prefix Device # Suffix

Company ID

CAT 4139

Product Number

4139

T: Tape & Reel

3: 3,000 / Reel

Tape & Reel (Note 7)

(Optional)

Package

TD: TSOT−23

− G

G: NiPdAu

Lead Finish

SERIES LED DRIVERS

Part Number Description

ÁÁÁÁÁÁÁ

CAT4137

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

CMOS Boost Converter − White LED Driver

ÁÁÁÁÁÁÁ

CAT4237

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

High Voltage CMOS Boost White LED Driver

ÁÁÁÁÁÁÁ

CAT4238

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

High Efficiency 10 LED Boost Converter

ÁÁÁÁÁÁÁ

CAT4139

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

22 V High Current Boost White LED Driver

ÁÁÁÁÁÁÁ

CAT4240

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

6 Watt Boost LED Driver

3. All packages are RoHS−compliant (Lead−free, Halogen−free).

4. The standard lead finish is NiPdAu.

5. The device used in the above example is a CAT4139TD−GT3 (TSOT−23, 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

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USA/Canada

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Phone: 81−3−5773−3850

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