CAT4109 3-Channel Constant-Current RGB LED Driver with Individual PWM Dimming FEATURES DESCRIPTION 3 independent current sinks up to 175mA rated 25V LED Current set by external low power control resistors Individual PWM control per channel Low dropout current source (0.4V at 175mA) Output Enable input for dimming “Zero” current shutdown mode 3V to 5.5V logic supply Thermal shutdown protection RoHS-compliant 16-lead SOIC package The CAT4109 is a 3-channel constant-current LED driver, requiring no inductor. LED channel currents up to 175mA are programmed independently via separate external resistors. Low output voltage operation of 0.4V at 175mA allows for more power efficient designs across wider supply voltage range. The three LED pins are compatible with high voltage up to 25V supporting applications with long strings of LEDs. Three independent control inputs PWM1, PWM2, PWM3, control respectivelly LED1, LED2, LED3 channels. The device also includes an output enable (OE) control pin to disable all three channels independently of the PWMx input states. APPLICATIONS Multi-color LED, Architectural Lighting LED signs and displays LCD backlight Thermal shutdown protection is incorporated in the device to disable the LED outputs whenever the die temperature exceeds 150ºC. The device is available in a 16-lead SOIC package. ORDERING INFORMATION Part Number Package Quantity per Reel Package Marking CAT4109V-GT2 SOIC-16* 2,000 CAT4109V * Lead Finish NiPdAu PIN CONFIGURATION TYPICAL APPLICATION CIRCUIT 16-Lead SOIC (W) Top View VIN 5V to 25V PGND 1 16 VDD GND 2 15 OE PWM3 3 14 NC PWM2 4 13 NC PWM1 5 12 NC RSET3 6 11 LED1 RSET2 7 10 LED2 RSET1 8 9 LED3 VDD 3V to 5.5V RED VDD LED1 GREEN LED2 BLUE LED3 OE PWM1 PWM2 CONTROLLER PWM3 CAT4109 RSET1 RSET2 RSET3 GND R1 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice C1 1µF 1 R2 PGND R3 Doc. No. MD-5042, Rev. A CAT4109 ABSOLUTE MAXIMUM RATINGS Parameter VDD Voltage Input Voltage Range (OE, PWM1, PWM2, PWM3) LED1, LED2, LED3 Voltage DC Output Current on LED1 to LED3 Storage Temperature Range Junction Temperature Range Lead Soldering Temperature (10sec.) ESD Rating on All Pins: Rating Units 6 -0.3V to 6V 25 200 -55 to +160 -40 to +150 300 V V V mA °C °C °C 2000 200 V • Human Body Model • Machine Model RECOMMENDED OPERATING CONDITIONS Parameter Range Units VDD 3.0 to 5.5 V Voltage applied to LED1 to LED3, outputs off up to 25 V Voltage applied to LED1 to LED3, outputs on up to 6* V Output Current on LED1 to LED3 2 to 175 mA Ambient Temperature Range -40 to +85 °C * Keeping LEDx pin voltage below 6V in operation is recommended to minimize thermal dissipation in the package. ELECTRICAL OPERATING CHARACTERISTICS DC CHARACTERISTICS Min and Max values are over recommended operating conditions unless specified otherwise. Typical values are at VDD = 5.0V, TAMB = 25°C Symbol Name IDD1 IDD2 IDD3 IDD4 ISHDN ILKG ROE Supply Current Outputs Off Supply Current Outputs Off Supply Current Outputs On Supply Current Outputs On Shutdown Current LED Output Leakage OE pull-down resistance VOE_IH VOE_IL OE logic high input voltage OE logic low input voltage VPWM_IH VPWM_IL IIL VRSETx TSD THYS PWMx logic high input voltage PWMx logic low input voltage Logic Input Leakage Current (PWMx) RSETx Regulated Voltage Thermal Shutdown Thermal Hysteresis ILED/IRSET RSET to LED Current Gain ratio VUVLO Conditions VLED = 5V, RSET = 24.9kΩ VLED = 5V, RSET = 5.23kΩ VLED = 0.5V, RSET = 24.9kΩ VLED = 0.5V, RSET = 5.23kΩ VOE = 0V VLED = 5V, Outputs Off -1 140 Typ Max Units 2 4 2 4 5 10 5 10 1 1 250 mA mA mA mA µA µA kΩ 1.2 V 0.7x VDD V 190 0.4 0.3x VDD VPWMx = VDD or GND 100mA LED Current Undervoltage Lockout (UVLO) Threshold Doc. No. MD-5042, Rev. A Min -5 0 5 µA 1.17 1.2 150 20 1.23 V °C °C 400 1.8 2 V © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice CAT4109 RECOMMENDED TIMING Min and Max values are over recommended operating conditions unless specified otherwise. Typical values are at VDD = 5.0V, TAMB = 25°C Symbol Name TPS TP1 Conditions Turn-On time, OE rising to ILED from Shutdown Turn-On time, OE or PWMx rising to I Turn-Off time, OE or PWMx falling to Min Typ Max Units ILED = 100mA 1.4 μs ILED = 100mA 600 ns ILED = 100mA ILED = 100mA ILED = 100mA 300 300 300 ns ns ns TP2 TR TF I LED rise time LED fall time TLO OE low time 1 μs THI OE high time 5 μs TPWRDWN OE low time to shutdown delay 4 8 ms TPWRDWN THI TLO Output Enable SHUTDOWN SHUTDOWN 0mA TP2 TF TPS TP1 TR ILED = (1.2V/RSET) x 400 90% LED Current 50% 50% 10% SHUTDOWN 0mA 0mA VIN Quiescent Current SHUTDOWN 0mA SHUTDOWN 0mA Figure 1. CAT4109 OE Timing OE OPERATION The Output Enable (OE) pin has two primary functions. When the OE input goes from high to low, all three LED channels are turned off. If OE remains low for longer than TPWRDWN, the device enters shutdown mode drawing “zero current” from the supply. Accurate linear dimming on OE is compatible with PWM frequencies from 100Hz to 5kHz for PWM duty cycle down to 1%. PWM frequencies up to 50kHz can be supported for duty cycles greater than 10%. When performing a combination of low frequencies and small duty cycles, the device may enter shutdown mode. This has no effect on the dimming accuracy, because the turn-on time TPS is very short, in the range of 1µs. The OE input can be used to adjust the contrast of the RGB LED by applying an external PWM signal. The device has a very fast turn-on time (from OE rising to LED on) allowing “instant on” when dimming LEDs. To ensure that PWM pulses are recognized, pulse width low time TLO should be longer than 1μs. The driver enters a “zero current” shutdown mode after a 4ms delay (typical) when OE is held low. When applying PWM signals to the three PWMx inputs and using the OE pin for dimming, the OE PWM frequency should be much lower to preserve the color mixing. © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice 3 Doc. No. MD-5042, Rev. A CAT4109 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 5V, VDD = 5V, C1 = 1μF, TAMB = 25°C unless otherwise specified. Quiescent Current vs. Input Voltage (ILED = 0mA) Quiescent Current vs. RSET Current 8.0 QUIESCENT CURRENT [mA] QUIESCENT CURRENT [mA] 1.2 No Load 1.0 0.8 0.6 4.0 2.0 0.0 0.4 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE [V] 0 5.5 100 200 300 RSET CURRENT [μA] 400 LED Current vs. LED Pin Voltage Quiescent Current vs. Input Voltage (ILED = 175mA) 200 6.0 Full Load LED CURRENT [mA] QUIESCENT CURRENT [mA] 6.0 5.5 5.0 4.5 160 120 80 40 0 4.0 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE [V] 0.0 5.5 0.2 0.4 0.6 0.8 LED PIN VOLTAGE [V] 1.0 LED Current Change vs. Input Voltage LED Current Change vs. Temperature 200 160 LED CURRENT [mA] LED CURRENT [mA] 200 120 80 40 0 160 120 80 40 0 3.0 Doc. No. MD-5042, Rev. A 3.5 4.0 4.5 5.0 INPUT VOLTAGE [V] 5.5 -40 4 0 40 80 TEMPERATURE [ºC] 120 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice CAT4109 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 5V, VDD = 5V, C1 = 1μF, TAMB = 25°C unless otherwise specified. RSET Pin Voltage vs. Temperature RSET Pin Voltage vs. Input Voltage 1.30 RSET VOLTAGE [V] RSET VOLTAGE [V] 1.30 1.25 1.20 1.15 1.10 1.25 1.20 1.15 1.10 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE [V] 5.5 -40 0 40 80 TEMPERATURE [ºC] 120 LED Current vs. RSET Resistor LED CURRENT [mA] 200 160 120 80 40 0 0 15 30 RSET [kΩ] 45 60 OE Transient Response at 1kHz © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice PWMx Transient Response 5 Doc. No. MD-5042, Rev. A CAT4109 PIN DESCRIPTIONS Name Pin Number Function PGND 1 Power Ground. GND 2 Ground Reference. PWM3 3 PWM control input for LED3 PWM2 4 PWM control input for LED2 PWM1 5 PWM control input for LED1 RSET3 6 LED current set pin for LED3 RSET2 7 LED current set pin for LED2 RSET1 8 LED current set pin for LED1 LED3 9 LED channel 3 cathode terminal LED2 10 LED channel 2 cathode terminal LED1 11 LED channel 1 cathode terminal NC 12 Not connected inside package NC 13 Not connected inside package NC 14 Not connected inside package OE 15 Output Enable input pin VDD 16 Device Supply pin PIN FUNCTION PGND is the power ground reference pin for the device. This pin must be connected to the GND pin and to the ground plane on the PCB. GND is the ground reference pin for the entire device. This pin must be connected to the ground plane on the PCB. LED1 to LED3 are the LED current sink inputs. These pins are connected to the bottom cathodes of the LED strings. The current sinks bias the LEDs with a current equal to 400 times the corresponding RSETx pin current. For the LED sink to operate correctly the voltage on the LED pin must be above 0.4V. Each LED channel can withstand voltages up to 25V. PWM1 to PWM3 are the control inputs respectively for LED1, LED2 and LED3 channels. When PWMx are low, the associated LED channels are turned off. When PWMx are high, the corresponding channels are turned on, assuming the OE input is also high. PWMx pins can not be left open and must be set to either to logic high or low. OE is the output enable input. When high, all LED channels are enabled according to the state of their corresponding PWMx control inputs. When low, all LED channels are turned off. This pin can be used to turn all the LEDs off independently of the state of the PWMx inputs. If the OE stays low for a duration longer than TPWRDWN, the device enters shutdown mode. RSET1 to RSET3 are the LED current set inputs. The current pulled out of these pins will be mirrored in the corresponding LED channel with a gain of 400. VDD is the positive supply pin voltage for the entire device. A small 1µF bypass ceramic capacitor is recommended between VDD pin and ground near the device. Doc. No. MD-5042, Rev. A 6 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice CAT4109 BLOCK DIAGRAM LED1 LED2 + VDD LED3 Tight current regulation for all channels is possible over a wide range of input and LED voltages due to independent current sensing circuitry on each channel. The LED channels have a low dropout of 0.4V or less for all current ranges and supply voltages. This helps improve heat dissipation and efficiency. 1.2V Ref RSET3 Current Setting RSET2 Current Setting RSET1 Current Setting CURRENT SINKS Upon power-up, an under-voltage lockout circuit sets all outputs to off. Once the VDD supply voltage is greater than the under-voltage lockout threshold, the device channel can be turned on. The on/off state of each channel LED1, LED2 and LED3 is independently controlled repectivelly by PWM1, PWM2, PWM3. When a PWMx is high, the associated LEDx channel is turned on. OE PWM1 PWM2 PWM3 PGND GND Figure 2. CAT4109 Functional Block Diagram BASIC OPERATION The CAT4109 uses 3 independent current sinks to accurately regulate the current in each LED channel to 400 times the current sink from the corresponding RSET pin. Each of the resistors tied to the RSET1, RSET2, RSET3 pins set the current respectively in the LED1, LED2, and LED3 channels. Table 1 shows standard resistor values for RSET and the corresponding LED current. Table 1. RSET Resistor Settings LED Current [mA] RSET[kΩ] 20 24.9 60 8.45 100 5.23 175 3.01 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice 7 Doc. No. MD-5042, Rev. A CAT4109 APPLICATION INFORMATION POWER DISSIPATION RECOMMENDED LAYOUT The power dissipation (PD) of the CAT4109 can be calculated as follows: Bypass capacitor C1 should be placed as close to the IC as possible. RSET resistors should be directly connected to the GND pin of the device. For better thermal dissipation, multiple via can be used to connect the GND pad to a large ground plane. It is also recommended to use large pads and traces on the PCB wherever possible to spread out the heat. The LEDs for this layout are driven from a separate supply (VLED+), but they can also be driven from the same supply connected to VDD. PD = (VDD × IDD ) + Σ(VLEDN × ILEDN ) where VLEDN is the voltage at the LED pin, and ILEDN is the associated LED current. Combinations of high VLED voltage or high ambient temperature can cause the CAT4109 to enter thermal shutdown. In applications where VLEDN is high, a resistor can be inserted in series with the LED string to lower PD. Thermal dissipation of the junction heat consists primarily of two paths in series. The first path is the junction to the case (θJC) thermal resistance which is defined by the package style, and the second path is the case to ambient (θCA) thermal resistance, which is dependent on board layout. The overall junction to ambient (θJA) thermal resistance is equal to: θJA = θJC + θCA For a given package style and board layout, the operating junction temperature TJ is a function of the power dissipation PD, and the ambient temperature, resulting in the following equation: TJ = TAMB + PD (θJC + θCA) = TAMB + PD θJA Figure 3. Recommended Layout When mounted on a double-sided printed circuit board with two square inches of copper allocated for “heat spreading”, the resulting θJA is about 74°C/W. For example, at 60°C ambient temperature, the maximum power dissipation is calculated as follow: PDmax = (TJmax - TAMB ) (150 - 60) = = 1.2W θJA 74 Doc. No. MD-5042, Rev. A 8 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice CAT4109 PACKAGE OUTLINE DRAWING SOIC 16-Lead 150mils (V) (1)(2) 0F0F E1 SYMBOL MIN A 1.35 1.75 A1 0.10 0.25 E MAX b 0.33 0.51 c 0.19 0.25 D 9.80 9.90 10.00 E 5.80 6.00 6.20 E1 3.80 3.90 4.00 e PIN#1 IDENTIFICATION NOM 1.27 BSC h 0.25 0.50 L 0.40 1.27 θ 0º 8º TOP VIEW D h θ A e b A1 SIDE VIEW c L END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions in millimeters. Angle in degrees. (2) Compiles with JEDEC standard-012. © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice 9 Doc. No. MD-5042, Rev. A CAT4109 EXAMPLE OF ORDERING INFORMATION (1) 1F1F1F Prefix CAT Device # Suffix 4109 V – G Package V: SOIC Company ID Product Number T2 Tape & Reel T: Tape & Reel 2: 2,000/Reel 4109 Lead Finish G: NiPdAu Blank: Matte-Tin Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard plated finish is NiPdAu. (3) The device used in the above example is a CAT4109V-GT2 (SOIC, NiPdAu, Tape & Reel, 2,000/Reel). (4) For additional temperature options, please contact your nearest ON Semiconductor Sales office. Doc. No. MD-5042, Rev. A 10 © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice CAT4109 REVISION HISTORY Date Revision Description 7-Jan-09 A Initial Issue 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. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303-675-2175 or 800-344-3860 Toll Free USA/Canada Fax: 303-675-2176 or 800-344-3867 Toll Free USA/Canada Email: [email protected] © 2009 SCILLC. All rights reserved. Characteristics subject to change without notice N. American Technical Support: 800-282-9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center: Phone: 81-3-5773-3850 11 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative Doc. No. MD-5038, Rev. A