CAT3603 3-Channel LED Driver in 3x3mm Package DESCRIPTION FEATURES The CAT3603 is a charge pump LED driver operating in either 1x (LDO) mode or 1.5x fractional mode regulating current through each of the 3 LED pins. Operation at a constant switching frequency of 1MHz allows the use of very small value ceramic capacitors. Drives up to 3 LEDs Current setting resistor Compatible with supply voltage of 3V to 5.5V Power efficiency up to 91% Output Current up to 30mA per LED Fractional pump 1x/1.5x Low noise input ripple Fixed High Frequency Operation 1MHz “Zero” Current Shutdown Mode Soft start and current limiting Short circuit protection 12-lead TDFN 3mm x 3mm package The CAT3603 drives 3 white LEDs in parallel and provides tightly matched regulated current to achieve uniform brightness in LCD backlighting applications. An external resistor, RSET, controls the output current level. The device can deliver up to 30mA over an input voltage supply range from 3V to 5.5V, making it ideal for battery-powered applications LED dimming can be accomplished using several methods; using a DC voltage to set the RSET pin current, applying a PWM signal on the EN pin, or adding a switched resistor in parallel with RSET. The EN input pin allows the device to be placed in powerdown mode with “near-zero” quiescent current. APPLICATION LCD Display Backlight Cellular Phones Digital Still Cameras Handheld Devices The device is available in the tiny 12-lead thin DFN 3mm x 3mm package with a max height of 0.8mm. ORDERING INFORMATION Part Number Package CAT3603HV2 TDFN-12 3x3 Green* Quantity Package per Reel Marking 2000 HABB * Lead Finish Matte-Tin For Ordering Information details, see page 11. PIN CONFIGURATION TYPICAL APPLICATION CIRCUIT 12-lead TDFN 3mm (Top view) Note: Unused LED channels must be connected to VOUT. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 1 Doc. No. 5017 Rev. C CAT3603 ABSOLUTE MAXIMUM RATINGS Parameter VIN, VOUT, LEDx voltage EN voltage RSET voltage Junction Temperature Range Storage Temperature Range Lead Temperature ESD Ratings Human Body Model (HBM) Machine Model (MM) Rating -0.3 to 7.0 -0.3 to VIN -0.3 to VIN -40 to +150 -65 to +160 300 Unit V V V °C °C °C 2000 200 V V RECOMMENDED OPERATING CONDITIONS Parameter VIN Ambient Temperature Range Input, Output, Bucket Capacitors ILED per LED pin IOUT Total Output Current Range 3 to 5.5 -40 to +85 1 ±20% typical 0 to 31 Unit V °C µF mA 0 to 150 mA Typical application circuit with external components are shown on page 1. ELECTRICAL OPERATING CHARACTERISTICS VIN = 3.6V, EN = High, ambient temperature of 25ºC (over recommended operating conditions unless specified otherwise). Symbol IQ VRSET ILED Parameter Quiescent Current RSET Regulated Voltage Programmed LED Current ILED-ACC LED Current Accuracy ILED-DEV ROUT LED Channel Matching Output Resistance (Open Loop) Charge Pump Frequency 1x to 1.5x Mode Transition Dropout Delay Input Leakage Current High Detect Threshold Low Detect Threshold Short Circuit Output Current Maximum Input Current Thermal Shutdown Thermal Hysteresis Undervoltage lock out (UVLO) threshold fOSC TDROPOUT IEN VEN ISC ILIM TSD THYS VUVLO Doc. No. 5017 Rev. C Conditions VEN = 0V, shutdown mode 1x Mode, No Load 1.5x Mode, No Load Min 1.17 IRSET = 5µA IRSET = 37µA IRSET = 78µA 0.5mA ≤ ILED ≤ 3mA 3mA ≤ ILED ≤ 30mA (ILED – ILEDAVG) / ILEDAVG 1x Mode 1.5x Mode, IOUT = 100mA 0.8 0.4 On Input EN On Input EN VOUT = GND VOUT > 1V 2 0.4 30 200 Typ 0.1 0.4 2.7 1.2 2.4 15.0 30.0 ±15 ±5 ±3 1.4 6.5 1.0 0.6 0.8 0.7 45 400 150 20 2 Max 1 1 5 1.23 2.5 10 1.3 0.9 1 1.3 60 600 Unit µA mA mA V mA mA mA % % % Ω Ω MHz ms µA V V mA mA ºC ºC V © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3603 TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 60mA (3 LEDs at 20mA), C1 = C2 = CIN = COUT = 1µF, TAMB = 25°C unless otherwise specified. Efficiency vs. Input Voltage (3 LEDs on) Efficiency vs. Total LED Current (3 LEDs) 100 100 EFFICIENCY [%] 90 1.5x Mode 80 70 60 20mA per LED 50 15mA per LED 70 60 VIN = 3.2V (1.5x Mode) 40 4.2 4.0 3.8 3.6 3.4 3.2 INPUT VOLTAGE [V] 3.0 0 20 40 60 80 LED CURRENT [mA] 100 Quiescent Current vs. Temperature (1x Mode) Quiescent Current vs. Input Voltage (1x Mode) 0.8 0.8 QUIESCENT CURRENT [mA] QUIESCENT CURRENT [mA] 80 50 40 0.6 0.4 0.2 LEDs Off 0.0 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 0.6 0.4 0.2 LEDs Off 0.0 4.2 -40 Quiescent Current vs. Input Voltage (1.5x Mode) 0 40 80 TEMPERATURE [°C] 120 Quiescent Current vs. Temperature (1.5x Mode) 6.0 QUIESCENT CURRENT [mA] 6.0 QUIESCENT CURRENT [mA] VIN = 4V (1x Mode) 90 EFFICIENCY [%] 1x Mode 5.0 4.0 3.0 2.0 1.0 LEDs Off 0.0 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 4.2 5.0 4.0 3.0 2.0 1.0 LEDs Off 0.0 -40 3 0 40 80 TEMPERATURE [°C] 120 Doc. No. 5017 Rev. C CAT3603 TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 60mA (3 LEDs at 20mA), C1 = C2 = CIN = COUT = 1µF, TAMB = 25°C unless otherwise specified. 5.0 4.0 3.0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 LED Current Change vs. Temperature 1x Mode 1.5x Mode 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 -40 SWITCHING FREQUENCY [MHz] 1.2 1.1 1.0 0.9 0.8 0.7 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 120 1.3 1.2 1.1 1.0 0.9 0.8 0.7 -40 4.2 Output Resistance vs. Input Voltage (1x Mode) 0 40 80 TEMPERATURE [°C] 120 Output Resistance vs. Input Voltage(1.5x Mode) 10 OUTPUT RESISTANCE [Ω] . 4 OUTPUT RESISTANCE [Ω] . 0 40 80 TEMPERATURE [°C] Switching Frequency vs. Temperature 1.3 3.0 VIN = 4V 4.2 Switching Frequency vs. Input Voltage SWITCHING FREQUENCY [MHz] 5.0 4.0 3.0 LED CURRENT CHANGE [%] LED CURRENT CHANGE [%] LED Current Change vs. Input Voltage 3 2 1 0 3.0 Doc. No. 5017 Rev. C 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 4.2 8 6 4 2 3.0 4 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 4.2 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3603 TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 60mA (3 LEDs at 20mA), C1 = C2 = CIN = COUT = 1µF, TAMB = 25°C unless otherwise specified. Switching Waveforms in 1.5x Mode Operating Waveforms in 1x Mode Power Up 3 LEDs at 20mA, VIN = 3.2V (1.5x Mode) Power Up 3 LEDs at 20mA, VIN = 4V (1x Mode) LED Current vs. RSET Line Transient Response in 1x Mode LED CURRENT [mA] 100 10 1 10 © 2006 Catalyst Semiconductor, Inc. 100 RSET [kohm] Characteristics subject to change without notice 1000 5 Doc. No. 5017 Rev. C CAT3603 TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 60mA (3 LEDs at 20mA), C1 = C2 = CIN = COUT = 1µF, TAMB = 25°C unless otherwise specified. Foldback Current Limit OUTPUT VOLTAGE [V] 5 1x mode 4 3 2 1 0 0 Doc. No. 5017 Rev. C 100 200 300 400 OUTPUT CURRENT [mA] 500 6 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3603 PIN DESCRIPTIONS Pin # 1 2 3 4 5 6 7 8 9 10 11 12 Name LED1 LED2 LED3 RSET EN VOUT VIN C1+ C1C2C2+ GND TAB Function LED1 cathode terminal (if not used, connect to VOUT)(1) LED2 cathode terminal (if not used, connect to VOUT)(1) LED3 cathode terminal (if not used, connect to VOUT)(1) The LED output current is set by the current sourced out of the RSET pin Device enable (active high) Charge pump output connected to the LED anodes Supply voltage Bucket capacitor 1 terminal Bucket capacitor 1 terminal Bucket capacitor 2 terminal Bucket capacitor 2 terminal Ground Reference Connect to GND on the PCB Note: (1) LED1, LED2, LED3 pins should not be left floating. They should be connected to the LED cathode, or tied to VOUT pin if not used. PIN FUNCTION C1+, C1- are connected to each side of the 1µF ceramic bucket capacitor C1. VIN is the supply pin for the charge pump. A small 1µF ceramic bypass capacitor is required between the VIN pin and ground near the device. The operating input voltage range is from 3.0V to 5.5V. C2+, C2- are connected to each side of the 1µF ceramic bucket capacitor C2. EN is the enable control logic input for all LED channels. Guaranteed levels of logic high and logic low are set at 1.3V and 0.4V respectively. LED1 to LED3 provide the internal regulated current for each of the LED cathodes. These pins enter a high impedance, zero current state whenever the device is placed in shutdown mode. In applications using less than three LEDs, all unused channels should be wired directly to VOUT. This ensures the channel is automatically disabled dissipating less than 200µA. RSET pin is regulated at 1.2V. An external resistor RSET connected from the RSET pin to GND sets the LED current. VOUT is the charge pump output that is connected to the LED anodes. A small 1µF ceramic bypass capacitor is required between the VOUT pin and ground near the device. TAB is the exposed pad underneath the package. For best thermal performance, the tab should be soldered to the PCB and connected to the ground plane. GND is the ground reference for the charge pump. The pin must be connected to the ground plane on the PCB. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 7 Doc. No. 5017 Rev. C CAT3603 BLOCK DIAGRAM Figure 2. CAT3603 Functional Block Diagram BASIC OPERATION At power-up, the CAT3603 starts operating in 1x mode where the output will be approximately equal to the input supply voltage (minus any internal voltage losses). If the output voltage is sufficient to regulate all LED currents, the device remains in 1x operating mode. In 1.5x mode, the output is approximately equal to 1.5 times the input supply voltage (minus any internal voltage losses), and high enough to achieve the nominal LED current. The above sequence is reinitialized every time the chip is powered-up or is taken out of shutdown mode (via EN pin). If the input voltage falls to a level where the regulated currents cannot be maintained, the device automa– tically switches into 1.5x mode. Doc. No. 5017 Rev. C 8 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3603 LED CURRENT SETTING is kept very low by design, and an input bypass capacitor of 1µF is sufficient. In 1x mode, the device operating in linear mode does not introduce switching noise back onto the supply. The LED current is set by the external resistor RSET connected between the RSET pin and ground. Table 1 lists various LED currents and the associated RSET resistor value for standard 1% precision surface mount resistors. Recommended Layout In 1.5x charge pump mode, the driver switches internally at a high frequency of 1MHz. It is recommended to minimize trace length to all four capacitors. A ground plane should cover the area under the driver IC as well as the bypass capacitors. Short connection to ground on capacitors CIN and COUT can be implemented with the use of multiple via. A copper area matching the TDFN exposed pad (GND) must be connected to the ground plane underneath. The use of multiple via improves the package heat dissipation. Table 1. RSET Resistor Selection LED Current (mA) 1 5 10 15 20 25 30 RSET (kΩ) 649 287 102 49.9 32.4 23.7 15.4 The unused LED channels must be disabled by connecting the respective LED pins to VOUT. A disabled channel sinks only 0.2mA typical. When the following equation is true on any channel, the driver turns off the LED channel: VOUT - VLED ≤ 1V (LED channel OFF) Note: The CAT3603 is designed to drive LEDs with forward voltage greater than 1V and is not compatible with resistive loads less than 5kΩ. External Components The driver requires a total of four external 1µF ceramic capacitors: two for decoupling input and output, and two for the charge pump. Both capacitor types X5R and X7R are recommended for the LED driver application. In the 1.5x charge pump mode, the input current ripple © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice Figure 3. Recommended Layout 9 Doc. No. 5017 Rev. C CAT3603 PACKAGE DRAWING AND DIMENSIONS Thin DFN 12-Lead 3mm x 3mm, 0.45mm Pitch C PIN 1 INDENT PIN 1 ID e 5xe E2 D A1 E A SYMBOL MIN NOM MAX A 0.70 0.75 0.80 A1 0.00 0.02 0.05 b 0.18 0.23 0.30 C b D2 L 0.20 REF D 2.90 3.00 3.10 D2 1.60 1.70 1.80 E 2.90 3.00 3.10 E2 2.30 2.40 2.50 0.35 0.45 e 0.45 L 0.55 Notes: (1) All dimensions are in millimeters, angles in degrees. (2) Complies with JEDEC specification MO-229. RECOMMENDED LAND PATTERN 0.95 0.45 2.40 1.70 3.00 0.23 4.00 Note: All dimensions are in millimeters, angles in degrees. Doc. No. 5017 Rev. C 10 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3603 EXAMPLE OF ORDERING INFORMATION Prefix Device # CAT 3603 Suffix HV2 – T2 Product Number 3603 Tape & Reel T: Tape & Reel 2: 2000/Reel Optional Company ID Package HV2: TDFN (Lead-free, Halogen-free) Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard lead finish is Matte-Tin. (3) The device used in the above example is a CAT3603HV2 –T2 (TDFN, Tape & Reel). (4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 11 Doc. No. 5017 Rev. C REVISION HISTORY Date 05/28/2006 06/03/06 Rev. A B 07/10/06 C Reason Initial Issue Update Description Update Recommended Operating Conditions Update Pin Configuration Update Pin Description Copyrights, Trademarks and Patents Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: DPP ™ AE2 ™ 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 GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS 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 ARISING 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 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 Catalyst Semiconductor product could create a situation where personal injury or death may occur. Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. 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 relevant product information before placing orders. Circuit diagrams illustrate typical semiconductor applications and may not be complete. Catalyst Semiconductor, Inc. Corporate Headquarters 1250 Borregas Avenue Sunnyvale, CA 94089 Phone: 408.542.1000 Fax: 408.542.1200 www.catsemi.com Document No: 5017 Revision: C Issue date: 07/10/2006