CAT4201 CATALYST | Alldatasheet
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© Catalyst Semiconductor, Inc. 1 Doc. No. MD-5025 Rev. D Characteristics subject to change without notice 350mA High Efficiency Step Down LED Driver
FEATURES
LED drive current up to 350mA Compatible with 12V and 24V standard systems Handles transients up to 40V Single Pin Control and Dimming function Power Efficiency up to 94% Drives LED strings of up to 32V Open and short LED protection Parallel configuration for higher output current RoHS-compliant TSOT-23 5-lead package
APPLICATIONS
12V and 24V Lighting Systems Automotive and Aircraft Lighting General lighting High Brightness 350mA LEDs
ORDERING INFORMATION
- Plated Finish: NiPdAu
DESCRIPTION
The CAT4201 is a high efficiency step-down converter optimized to drive high current LEDs. A patented switching control algorithm allows highly efficient and accurate LED current regulation. A single RSET resistor sets the full sca le LED string current up to 350mA from supplies as high as 36V. The switching architecture of the CAT4201 results in extremely low internal power dissipation allowing the device to be housed in a tiny package without the need for dedicated heat sinking. The device is compatible with switching frequencies of up to 1MHz, making it ideal for applications requiring small footprint and low value external inductors. Analog dimming and LED shutdown control is provided via a single input pin, CTRL. Additional features include overload current protection and thermal shutdown. The device is available in the low profile 5-lead thin SOT23 package and is ideal for space constrained applications. PIN CONFIGURATION TSOT-23 5-lead (Top View) TYPICAL APPLICATION CIRCUIT D: Central Schottky CMDSH05-4 L: Sumida CDRH6D26-220 See Table 1 on page 6 for external component selection. For Ordering Information details, see page 14. VBAT CAT4201 RSET SW CTRL GND Bulb Replacement CTRL SW GND CAT4201 VBAT VBAT 4.7µF 10µF 10kΩ L D RSET 22µH 300mA
Doc. No. MD-5025 Rev. D 2 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice Absolute Maximum Ratings0F (1) Parameters Ratings Units VBAT, SW, CTRL -0.3 to +40 V RSET -0.3 to +5 V Switch SW peak current 1 A Storage Temperature Range -65 to +160 °C Junction Temperature Range -40 to +150 °C Lead Temperature 300 °C Recommended Operating Conditions Parameters Ratings Units VBAT voltage (2) (3) 6.5 to 36 (2) V SW voltage 0 to 36 V Ambient Temperature Range -40 to +125 °C LED Current 50 to 350 mA Switching Frequency 50 to 1000 kHz
ELECTRICAL CHARACTERISTICS
VIN = 13V, ambient temperature of 25ºC (over recommended operating conditions unless specified otherwise) Symbol Parameter Conditions Min Typ Max Units IQ Operating Supply Current on VBAT pin 0.4 1 mA ISD Idle Mode Supply Current on VBAT pin CTRL = GND 90 µA VFB RSET Pin Voltage 2 LEDs with I LED= 300mA 1.15 1.2 1.25 V ILED Programmed LED Current R1 = 33kΩ R1 = 10kΩ R1 = 8.25kΩ 270 100 300 350 330 mA VCTRL-FULL CTRL Voltage for 100% Brightness 2.6 3.1 V VCTRL-EN CTRL Voltage to Enable LEDs LED enable voltage threshold 0.9 1.2 V VCTRL-SD CTRL Voltage to Shutdown LEDs LED disable voltage threshold 0.4 0.9 V ICTRL CTRL pin input bias VCTRL = 3V VCTRL = 12V 40 200 µA RSW Switch “On” Resistance I SW = 300mA 0.9 1.5 Ω TSD Thermal Shutdown 150 ºC THYST Thermal Hysteresis 20 ºC η Efficiency Typical Application Circuit 86 % Notes: (1) Stresses above those listed under “Absol ute Maximum Ratings” may cause permanent damage to the device. These are stress ra tings only, and functional operation of the device at these or any ot her conditions outside of those lis ted in the operational sectio ns of this specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability. (2) The VBAT pin voltage should be at least 3V greater than the to tal sum of the LED forward voltages in order to operate at no minal LED current. (3) During power-up, the slew rate of the input supply should be greater than 1µs for every 5V increase of VBAT.
© Catalyst Semiconductor, Inc. 3 Doc. No. MD-5025 Rev. D Characteristics subject to change without notice Typical Operation Characteristics VIN = 13V, ILED = 300mA, L = 22μH, C1= 4.7μF, C2 = 10μF, TAMB = 25°C unless otherwise specified Input Operating Supply Current 0.0 0.2 0.4 0.6 0.8 1.0 8 1 01 21 41 61 82 02 22 4 INPUT VOLTAGE [V] QUIESCENT CURRENT [mA] Idle Mode Supply Current (CTRL = 0V) 100 150 200 0 4 8 1 21 62 02 4 INPUT VOLTAGE [V] IDLE CURRENT [μA] CTRL Input Bias Current 100 150 200 250 02468 1 0 1 2 CTRL VOLTAGE [V] CTRL BIAS CURRENT [μA] . RSET Voltage vs. Temperature 1.10 1.15 1.20 1.25 1.30 -40 0 40 80 120 TEMPERATURE [°C] RSET VOLTAGE [V] VIN = 13V RSET Voltage vs. CTRL Voltage 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 01234 CTRL VOLTAGE [V] RSET VOLTAGE [V] +25°C -40°C + 85°C LED Current vs. RSET 100 200 300 400 5 1 01 52 02 53 03 5 RSET [kΩ] LED CURRENT [mA]
Doc. No. MD-5025 Rev. D 4 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice Typical Operation Characteristics VIN = 13V, ILED = 300mA, L = 22μH, C1= 4.7μF, C2 = 10μF, TAMB = 25°C unless otherwise specified Switching Frequency vs. Input Voltage (1 LED) 100 200 300 400 500 8 1 21 62 02 42 8 INPUT VOLTAGE [V] SWITCHING FREQUENCY [kHz] 150mA 300mA Switching Frequency vs. Input Voltage (2 LEDs) 100 200 300 400 500 600 700 8 1 21 62 02 42 8 INPUT VOLTAGE [V] SWITCHING FREQUENCY [kHz] 300mA 150mA Switching Frequency vs. Temperature 100 200 300 400 500 - 4 004 0 8 0 1 2 0 TEMPERATURE [°C] SWITCHING FREQUENCY [kHz] 150mA 300mA VIN = 13V Switch ON Resistance vs. Input Voltage 0.4 0.8 1.2 1.6 8 1 01 21 41 61 82 02 22 4 INPUT VOLTAGE [V] SW RESISTANCE [ Ω] Efficiency vs. Input Voltage (1 LED) 100 8 1 01 21 41 61 82 02 22 4 INPUT VOLTAGE [V] EFFICIENCY [%]300mA 150mA Efficiency vs. Input Voltage (2 LEDs) 100 8 1 01 21 41 61 82 02 22 4 INPUT VOLTAGE [V] EFFICIENCY [%] 300mA 150mA
© Catalyst Semiconductor, Inc. 5 Doc. No. MD-5025 Rev. D Characteristics subject to change without notice Typical Operation Characteristics VIN = 13V, ILED = 300mA, L = 22μH, C1= 4.7μF, C2 = 10μF, TAMB = 25°C unless otherwise specified Efficiency vs. LED Current 100 100 150 200 250 300 350 LED CURRENT [mA] EFFICIENCY [%] 1 LED
2 LEDs
LED Current Regulation vs. Temperature -10 -40 0 40 80 120 TEMPERATURE [°C] LED CURRENT VARIATION [%] . VIN = 13V LED Current vs. Input Voltage (1 LED) 100 150 200 250 300 350 0 4 8 1 21 62 02 42 8 INPUT VOLTAGE [V] LED CURRENT [mA] VF = 3.3V 300mA VF = 3.1V 150mA LED Current vs. Input Voltage (2 LEDs) 100 150 200 250 300 350 0 4 8 1 21 62 02 42 8 INPUT VOLTAGE [V] LED CURRENT [mA] VF = 3.3V 300mA VF = 3.1V 150mA Switching Waveforms CTRL Power-up
Doc. No. MD-5025 Rev. D 6 © Catalyst Semiconductor, Inc. current, switching frequency and component size.
1 LED 2 LEDs
Table 1. External Component Selection Note: Larger C2 capacitor values allow to reduce further the LED ripple current if needed.
© Catalyst Semiconductor, Inc. 7 Doc. No. MD-5025 Rev. D Characteristics subject to change without notice PIN DESCRIPTION Pin Name Function 1 CTRL Analog dimming control and shutdown pin. 2 GND Ground reference. 3 RSET RSET pin. A resistor connected between the pin and ground sets the average LED current. 4 SW Interface to the inductor. 5 VBAT Supply voltage for the device. PIN FUNCTION VBAT is the supply input to the device. Typical current conduction into this pin is less than 1mA and voltage transients of up to 40V can be applied. To ensure accurate LED current regul ation, the VBAT voltage should be 3V higher than the total forward voltage of the LED string. A bypass capacitor of 4.7µF or larger is recommended between VBAT and GND. CTRL is the analog dimming and control input. An internal pull-down current of 20µA allows the LEDs to shutdown if CTRL is left floating. Voltages of up to 40V can be safely handled by the CTRL input pin. When the CTRL voltage is less than 0.9V (typ), the LEDs will shutdown to zero current. When the CTRL voltage is greater than about 2.6V, full scale brightness is applied to the LED output. At voltages of less than around 2.6V, the LED current is progressively dimmed until shutdown. For lamp replacement applications, or applications where operation in dropout mode is expected, it is recommended that the CTRL pin voltage be derived from the LED cathode terminal. GND is the ground reference pin. This pin should be connected directly to the ground plane on the PCB. SW pin is the drain terminal of the internal low resistance high-voltage power MOSFET. The inductor and the Schottky diode anode should be connected to the SW pin. Voltages of up to 40V can be safely handled on the SW pin. Traces going to the SW pin should be as short as possible with minimum loop area. The device can handle safely “open-LED” or “shorted-LED” fault conditions. RSET pin is regulated at 1.2V. A resistor connected between the RSET pin and ground sets the LED full- scale brightness current. The external resistance value and the CTRL pin voltage determine the LED current during analog dimming.
Doc. No. MD-5025 Rev. D 8 © Catalyst Semiconductor, Inc. Figure 1. CAT4201 Simplified Block Diagram designed to drive series connected high-power LEDs. can be driven with bias currents of up to 350mA. equal to half of the peak switching current. used to calculate the LED current. Table 2. RSET Resistor Selection
© Catalyst Semiconductor, Inc. 13 Doc. No. MD-5025 Rev. D Characteristics subject to change without notice PACKAGE OUTLINE DRAWING TSOT-23 5-Lead (TD)1F (1)(2) 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 D2 . 9 0 B S C E2 . 8 0 B S C 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 Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC standard MO-193. For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf.
Doc. No. MD-5025 Rev. D 14 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice EXAMPLE OF ORDERING INFORMATION2F (1) ORDERING PART NUMBER CAT4201TD-GT3 Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard plated finish is NiPdAu on all pins. (3) The device used in the above example is a CA T4201TD-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 4201 TD -G T3 Company ID Product Number 4201 Plated Finish G: NiPdAu Package TD: TSOT Tape & Reel T: Tape & Reel 3: 3000/Reel
REVISION HISTORY
Updated Typical Application Circuit Added “External Component Selection” Table Added “Capacitor Selection” information Updated Figures 5, 6, 7, 8 21-Feb-08 C Update Description, change patent-pending to patented Update Package Outline Drawing 17-Jun-08 D Update Supply Voltage 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. Catalyst Semiconductor, Inc. Corporate Headquarters
2975 Stender Way
Santa Clara, CA 95054 Phone: 408.542.1000 Document No: MD-5025 Fax: 408.542.1200 Revision: D 0Hwww.catsemi.com Issue date: 02/21/08