CAT4139 CATALYST | Alldatasheet
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Technical content
© Catalyst Semiconductor, Inc. 1 Doc. No. MD-5032 Rev. A Characteristics subject to change without notice
FEATURES
Switch Current Limit 750mA Drives LED strings up to 22V Up to 87% Efficiency Low Quiescent Ground Current 0.6mA 1MHz Fixed Frequency Low noise Operation Soft start “in-rush” current limiting Shutdown current less than 1μA Open LED Overvoltage Protection Automatic Shutdown at 1.9V (UVLO) Thermal overload protection TSOT-23 5-Lead (1mm max height)
APPLICATIONS
GPS Navigation Systems Portable Media Players Handheld Devices
ORDERING INFORMATION
Part Number Package Quantity per Reel Package Marking CAT4139TD-GT3 TSOT23-5* 3000 TP * NiPdAu Plated Finish, RoHS compliant For Ordering Information details, see page 12.
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 1MHz 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 22V. 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 (1mm max height) 5-lead TSOT-23 package for space critical applications. PIN CONFIGURATION TYPICAL APPLICATION CIRCUIT TSOT-23 5-Lead Top View VIN CAT4139 VIN LD VOUT 9 strings at 20mA IOUT 1.62Ω 180mA (300mV) 4.7µF 1µF 35V FBSHDN SW GND ON 22µH OFF 1kΩ 22V High Current Boost White LED Driver L: Sumida CDRH6D28-220 D: Central CMSH1-40 (rated 40V) VIN FB SHDN SW GND
Doc. No. MD-5032 Rev. A 2 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 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 ºC Junction Temperature Range -40 to +150 ºC Lead Temperature 300 ºC RECOMMENDED OPERATING CONDITIONS Typical application circuit with external components are shown on page 1. Parameters Range Units VIN up to 5.5 V SW pin voltage 0 to 22 V Ambient Temperature Range(1) -40 to +85 ºC DC ELECTRICAL CHARACTERISTICS VIN = 3.6V, ambient temperature of 25ºC (over recommended operating conditions unless specified otherwise). Symbol Parameter Test Conditions Min Typ Max Units IQ Operating Current VFB = 0.2V VFB = 0.4V (not switching) 0.6 0.1 1.5 0.6 mA ISD Shutdown Current VSHDN¯¯¯¯¯ = 0V 0.1 1 µA VFB FB Pin Voltage 9 x 3 LEDs, I OUT = 180mA 285 300 315 mV IFB FB pin input leakage 1 µA ILED Programmed LED Current R1 = 10Ω R1 = 3Ω 28.5 100 31.5 mA VIH VIL Enable Threshold Level Shutdown Threshold Level 0.4 0.8 0.7 1.5 V V FSW Switching Frequency 0.8 1.0 1.3 MHz ILIM Switch Current Limit VIN = 3.6V VIN = 5V 600 750 mA RSW Switch “On” Resistance I SW = 100mA 1.0 2.0 Ω ILEAK Switch Leakage Cu rrent Switch Off, V SW = 5V 1 5 µA TSD Thermal Shutdown 150 ºC THYST Thermal Hysteresis 20 ºC 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 92 16 % Notes: (1) TSOT23-5 package thermal resistance θJA = 135°C/W when mounted on board over a ground plane.
© Catalyst Semiconductor, Inc. 3 Doc. No. MD-5032 Rev. A Characteristics subject to change without notice TYPICAL CHARACTERISTICS VIN = 5.0V, IOUT = 180mA, TAMB = 25ºC, with typical application circuit unless otherwise specified. Quiescent Current vs. VIN (Not Switching) 100 150 200 INPUT VOLTAGE [V] QUIESCENT CURRENT [μA] . VFB = 0.4V Quiescent Current vs. VIN (Switching) 0.0 0.5 1.0 1.5 2.0 INPUT VOLTAGE [V] QUIESCENT CURRENT [mA] FB Pin Voltage vs. Temperature 297 298 299 300 301 302 303 -50 0 50 100 150 TEMPERATURE [ºC] FB PIN VOLTAGE [mV] FB Pin Voltage vs. Output Current 290 295 300 305 310 80 100 120 140 160 180 200 OUTPUT CURRENT [mA] FB PIN VOLTAGE [mV] Switching Frequency vs. Supply Voltage 0.8 0.9 1.0 1.1 1.2 INPUT VOLTAGE [V] SWITCHING FREQUENCY [MHz] Switch ON Resistance vs. Input Voltage 0.0 0.5 1.0 1.5 2.0 INPUT VOLTAGE [V] SWITCH RESISTANCE [ Ω]
Doc. No. MD-5032 Rev. A 4 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice TYPICAL CHARACTERISTICS VIN = 5.0V, IOUT = 180mA, TAMB = 25ºC, with typical application circuit unless otherwise specified. Output Current vs. Input Voltage 100 120 140 160 180 200 INPUT VOLTAGE [V] LED CURRENT [mA] Output Current Regulation -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 INPUT VOLTAGE [V] IOUT VARIATION [%] Efficiency vs. Output Current 80 100 120 140 160 180 200 OUTPUT CURRENT [mA] EFFICIENCY [%] Efficiency vs. Input Voltage INPUT VOLTAGE [V] EFFICIENCY [%] IOUT = 120mA IOUT = 180mA Power-up at 180mA Switching Waveform
© Catalyst Semiconductor, Inc. 5 Doc. No. MD-5032 Rev. A Characteristics subject to change without notice TYPICAL CHARACTERISTICS VIN = 5.0V, IOUT = 180mA, TAMB = 25ºC, with typical application circuit unless otherwise specified. Maximum Output Current 100 150 200 250 300 INPUT VOLTAGE [V] MAX OUTPUT CURRENT [mA] VOUT = 9V VOUT = 14V Shutdown Voltage Switch Current Limit 600 650 700 750 800 850 900 INPUT VOLTAGE [V] SWITCH CURRENT LIMIT [mA] VOUT = 9V VOUT = 12V 0.2 0.4 0.6 0.8 1.0 INPUT VOLTAGE [V] SHUTDOWN VOLTAGE [V] -40°C-25°C 85°C 125°C
Doc. No. MD-5032 Rev. A 6 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice PIN DESCRIPTION VIN is the supply input for the internal logic. The device is compatible with supply voltages down to 2.8V and up to 5.5V. It is recommended that a small bypass ceramic capacitor (4.7 μF) be placed between the VIN and GND pins near the device. If the supply voltage drops below 1.9V, the device stops switching. SHDN¯¯¯¯¯ is the shutdown logic input. When the pin is tied to a voltage lower than 0.4V, the device is in shutdown mode, drawing nearly zero current. When the pin is connected to a voltage higher than 1.5V, 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 24V, the device enters a low power operating mode preventing the SW voltage from exceeding the maximum rating. FB feedback pin is regulated at 0.3V. A resistor con- nected between the FB pin and ground sets the LED current according to the formula: I LED = 0.3V / R1 The lower LED cathode is connected to the FB pin. Pin # Name Function 1 SW Switch pin. This is the dr ain 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. SIMPLIFIED BLOCK DIAGRAM VIN VIN VOUT Current Sense Ref 300mV ILED RS SHDN Thermal Shutdown & UVLO 1MHz Oscillator Over Voltage Protection PWM Logic Driver GND SW FB
© Catalyst Semiconductor, Inc. 7 Doc. No. MD-5032 Rev. A Characteristics subject to change without notice DEVICE OPERATION The CAT4139 is a fixed frequency (1MHz), 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 0.3V acro ss the feedback resistor connected to the feedback pin (FB). The value of the resistor sets the LED current accordingly (0.3V/R1). During the initial power-up st age, 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 24V, 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 150ºC. In the event of a thermal overload condition the device will automatically shutdown and wait till the junction temperatures cools to 130ºC before normal operation is resumed.
APPLICATION INFORMATION
EXTERNAL COMPONENT SELECTION CAPACITORS The CAT4139 only requires small ceramic capacitors of 4.7 μF on the input and 1µF on the output. Under normal condition, a 4.7µF input capacitor is sufficient. For applications with higher output power, a larger input capacitor of 10µF may be appropriate. X5R and X7R capacitor types are i deal due to their stability across temperature range. Inductor A 22µH 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 800mA or higher are recommended for most applications. Sumida CDRH6D28-220 22µH inductor has a rated current of 1.2A and a series resistance (D.C.R.) of 128mΩ 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 1MHz. Central Semiconductor Schottky rectifier CMSH1-40 (1A 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 = 0.3V / LED current Table 1. Resistor R1 and LED Current
Doc. No. MD-5032 Rev. A 8 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 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 24V. 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 6mW (about 1.6mA input current with a 3.6V supply). The SW pin clamps at a voltage below its maximum rating of 40V. There is no need to use an external zener diode between VOUT and the FB pin. A 35V rated C2 capacitor is required to prevent any overvoltage damage in the open LED condition. Open LED Disconnect and Reconnect Open LED Disconnect Open LED Output Voltage INPUT VOLTAGE [V] OUTPUT VOLTAGE [V] Open LED Protection Circuit VIN CAT4139 VIN VOUT L Schottky 40V (Central CMSH05-4) D 4.7µF 1µF 15Ω FBSHDN SW GND ON 22µH OFF Open LED Supply Current 1.0 1.5 2.0 2.5 INPUT VOLTAGE [V] INPUT CURRENT [mA]
© Catalyst Semiconductor, Inc. 11 Doc. No. MD-5032 Rev. A Characteristics subject to change without notice PACKAGE OUTLINES DRAWING TSOT-23 5-Lead (TD) (1)(2) Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC standard MO-193. θ E1 E e b D c A TOP VIEW SIDE VIEW END VIEW L SYMBOL MIN NOM MAX A1 . 0 0 A1 0.01 0.05 0.10 A2 0.80 0.87 0.90 b0 . 3 0 0 . 4 5 c 0.12 0.15 0.20 D 2.90 BSC E 2.80 BSC E1 1.60 BSC e0 . 9 5 T Y P L 0.30 0.40 0.50 L1 0.60 REF L2 0.25 BSC θ 0º 8º
© Catalyst Semiconductor, Inc. 12 Doc. No. MD-5032 Rev. A Characteristics subject to change without notice EXAMPLE OF ORDERING INFORMATION1 SERIES LED DRIVERS Part Number Description CAT4137 CMOS Boost Converter – White LED Driver CAT4237 Hi gh Voltage CMOS Boost White LED Driver CAT4238 Hi gh Efficiency 10 LED Boost Converter CAT4139 22V Hi gh Current Boost White LED Driver CAT4240 6 Watt Boost LED Driver Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard lead finish is NiPdAu. (3) The device used in the above example is a CA T4139–GT3 (TSOT-23, NiPdAu, Tape & Reel). (4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office. Prefix Device # Suffix CAT 4139 TD – G T3 Optional Company ID Product Number 4139 Tape & Reel T: Tape & Reel 3: 3000/Reel Package TD: TSOT-23 Lead Finish G: NiPdAu
REVISION HISTORY
Date Rev. Reason 11/06/2007 A Initial Issue Catalyst Semiconductor, Inc. Corporate Headquarters
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Santa Clara, CA 95054 Phone: 408.542.1000 Document No: MD-5032 Fax: 408.542.1200 Revision: A www.catsemi.com Issue date: 11 /06/07 Copyrights, Trademarks and Patents © Catalyst Semiconductor, Inc. Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: Adaptive Analog™, Beyond Memory™, DPP™, EZDim™, LDD™, MiniPot™, Quad-Mode™ and Quant um Charge Programmable™ Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products. CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUAR ANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRO DUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARIS ING OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES. Catalyst Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgica l implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconduct or product could create a situation where personal injury or death may occur. Catalyst Semiconductor reserves the right to make changes to or discontinue any produ ct or service descr ibed herein without not ice. Products with data sheets labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale. Catalyst Semiconductor advises customers to obtain the current version of the rele vant product informati on before placing order s. Circuit diagrams illustrate typical semiconductor applications and may not be complete.