CAT4104 700 mA Quad Channel Constant Current LED Driver Description The CAT4104 provides four matched low dropout current sinks to drive high−brightness LED strings up to 175 mA per channel. The LED channel current is set by an external resistor connected to the RSET pin. The LED pins are compatible with high voltage up to 25 V supporting applications with long strings of LEDs. The EN/PWM logic input supports the device enable and high frequency external Pulse Width Modulation (PWM) dimming control. Thermal shutdown protection is incorporated in the device to disable the LED outputs whenever the die temperature exceeds 150°C. The device is available in the 8−pad TDFN 2 mm x 3 mm package and the SOIC 8−Lead 150 mil wide package. Features • • • • • • • • • 4 Matched LED Current Sinks up to 175 mA Up to 25 V Operation on LED Pins Low Dropout Current Source (0.4 V at 175 mA) LED Current Set by External Resistor High Frequency PWM Dimming via EN/PWM “Zero” Current Shutdown Mode Thermal Shutdown Protection TDFN 8−pad 2 x 3 mm and SOIC 8−lead Packages These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant http://onsemi.com PIN CONNECTIONS LED1 1 RSET LED2 VIN LED3 EN/PWM LED4 GND SOIC 8−lead (Top View) 1 LED3 RSET VIN EN/PWM LED4 GND LED1 LED2 TDFN 8−pad (Top View) Applications • Automotive Lighting • General and Architectural Lighting • LCD Backlight TDFN−8 VP SUFFIX CASE 511AK SOIC−8 V SUFFIX CASE 751BD MARKING DIAGRAMS VCC 3 V to 25 V CAT4104V HC LEDs VIN 5V OFF ON R1 768 W CAT4104V = CAT4104V HC = CAT4104VP2 CAT4104 LED1 VIN EN/PWM RSET GND LED2 ORDERING INFORMATION LED3 LED4 Device 175 mA Figure 1. Typical Application Circuit Package Shipping CAT4104V−GT3 (Note 1) SOIC−8 (Pb−Free) 3,000/ Tape & Reel CAT4104VP2−GT3 (Note 1) TDFN−8 (Pb−Free) 3,000/ Tape & Reel 1. Lead Finish is NiPdAu © Semiconductor Components Industries, LLC, 2010 March, 2010 − Rev. 2 1 Publication Order Number: CAT4104/D CAT4104 Table 1. ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit VIN, RSET, EN/PWM Voltages −0.3 to 6 V LED1, LED2, LED3, LED4 Voltages −0.3 to 25 V Storage Temperature Range −65 to +160 _C Junction Temperature Range −40 to +150 _C 300 _C Lead Temperature 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 Parameter Rating Unit VIN 3.0 to 5.5 V Voltage applied to LED1 to LED4, outputs off up to 25 V Voltage applied to LED1 to LED4, outputs on up to 6 (Note 2) V Ambient Temperature Range −40 to +85 _C ILED per LED pin 10 to 175 mA 2. Keeping LEDx pin voltage below 6 V in operation is recommended to minimize thermal dissipation in the package. NOTE: Typical application circuit with external components is shown on page 1. Table 3. ELECTRICAL OPERATING CHARACTERISTICS (Min and Max values are over the recommended operating conditions unless specified otherwise. Typical values are at VIN = 5.0 V, TAMB = 25°C.) Name Symbol ILED−ACC Conditions LED Current Accuracy Min Typ Max % ±2 I LEDNOM * I LED Units I LEDNOM ILED−DEV LED Channel Matching I LED * I LEDAVG I LEDAVG (Note 3) VDOUT Dropout Voltage VRSET RSET Pin Voltage IQ Quiescent Current No LED, RSET = Float No LED, RSET = 770 W IQSHDN Shutdown Current VEN = 0 V REN/PWM VHI VLO −5 ILED = 175 mA +5 400 1.17 EN/PWM Pin − Internal pull−down resistance − Logic High Level − Logic Low Level ±1 1.2 % mV 1.23 0.6 6 V mA 1 mA 0.4 kW V V 200 1.3 TSD Thermal Shutdown 150 °C THYS Thermal Hysteresis 20 °C ILED/IRSET VUVLO RSET to LED Current gain ratio 25 mA LED current Undervoltage lockout (UVLO) threshold 100 2.0 3. Min and Max values are tested for ILED = 50 mA, VIN = 3.5 V, VLEDx = 0.4 V, TAMB = 25°C. http://onsemi.com 2 V CAT4104 Table 4. RECOMMENDED EN/PWM TIMING (Min and Max values are over the recommended operating conditions unless specified otherwise. Typical values are at VIN = 5.0 V, TAMB = 25°C.) Name Symbol Conditions Min Typ Max Units TPS Turn−On time, EN/PWM rising to ILED from shutdown ILED = 175 mA ILED = 80 mA 1.5 1.3 ms TP1 Turn−On time, EN/PWM rising to ILED ILED = 175 mA 600 ns TP2 Turn−Off time, EN/PWM falling to ILED ILED = 175 mA ILED = 80 mA 400 300 ns TR LED rise time ILED = 175 mA ILED = 80 mA 700 440 ns TF LED fall time ILED = 175 mA ILED = 80 mA 360 320 ns TLO EN/PWM low time 1 ms THI EN/PWM high time 5 ms TPWRDWN EN/PWM low time to shutdown delay 4 THI 8 ms TPWRDWN TLO EN/PWM SHUTDOWN POWERDOWN TP2 LED CURRENT SHUTDOWN 0 mA TF TP1 TR TPS 50% 50% I LED + 1.2 V R SET SHUTDOWN 0 mA 100 90% 10% 0 mA QUIESCENT CURRENT SHUTDOWN 0 mA SHUTDOWN 0 mA Figure 2. CAT4104 EN/PWM Timing EN/PWM Operation The EN/PWM pin has two primary functions. One function enables and disables the device. The other function turns the LED channels on and off for PWM dimming control. The device has a very fast turn−on time (from EN/PWM rising to LED on) and allows “instant on” when dimming LED using a PWM signal. Accurate linear dimming is compatible with PWM frequencies from 100 Hz to 5 kHz for PWM duty cycle down to 1%. PWM frequencies up to 50 kHz 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 1 ms. To ensure that PWM pulses are recognized, pulse width low time TLO should be longer than 1 ms. The CAT4104 enters a “zero current” shutdown mode after a 4 ms delay (typical) when EN/PWM is held low. http://onsemi.com 3 CAT4104 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 5 V, VCC = 5 V, LED forward voltage = 3.5 V, CIN = 1 mF, TAMB = 25°C unless otherwise specified.) 8 No Load QUIESCENT CURRENT (mA) QUIESCENT CURRENT (mA) 1.2 1.0 0.8 0.6 0.4 3.0 3.5 4.0 4.5 5.0 2 0.5 1.0 1.5 2.0 RSET CURRENT (mA) Figure 3. Quiescent Current vs. Input Voltage (RSET Open) Figure 4. Quiescent Current vs. RSET Current 200 Full Load 160 LED CURRENT (mA) 6.5 6.0 5.5 120 80 40 3.0 3.5 4.0 4.5 5.0 0 5.5 0 0.2 0.4 0.6 0.8 INPUT VOLTAGE (V) LED PIN VOLTAGE (V) Figure 5. Quiescent Current vs. Input Voltage (Full Load) Figure 6. LED Dropout vs. LED Pin Voltage 200 200 160 160 120 80 40 0 0 INPUT VOLTAGE (V) LED CURRENT (mA) QUIESCENT CURRENT (mA) LED CURRENT (mA) 4 0 5.5 7.0 5.0 6 1.0 120 80 40 3.0 3.5 4.0 4.5 5.0 0 −40 5.5 0 40 80 VIN (V) TEMPERATURE (°C) Figure 7. LED Line Regulation Figure 8. LED Current Change vs. Temperature http://onsemi.com 4 120 CAT4104 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 5 V, VCC = 5 V, LED forward voltage = 3.5 V, CIN = 1 mF, TAMB = 25°C unless otherwise specified.) 1000 200 LED CURRENT (mA) LED CURRENT (mA) 160 100 120 80 40 0.1 1 0 10 2 3 4 5 Figure 9. LED Current vs. RSET Resistor Figure 10. LED Current vs. LED Pin Voltage 1.25 1.25 RSET VOLTAGE (V) 1.30 1.20 1.15 3.0 1 LED PIN VOLTAGE (V) 1.30 1.10 0 RSET (kW) 3.5 4.0 4.5 5.0 1.20 1.15 1.10 −40 5.5 6 0 40 80 120 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 11. RSET Pin Voltage vs. Input Voltage Figure 12. RSET Pin Voltage vs. Temperature 1.0 LED OFF CURRENT (mA) RSET VOLTAGE (V) 10 0.8 0.6 −40°C 0.4 25°C 0.2 125°C 0 0 5 10 15 20 25 LED PIN VOLTAGE (V) Figure 13. LED Off Current vs. LED Pin Voltage http://onsemi.com 5 30 CAT4104 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 5 V, VCC = 5 V, LED forward voltage = 3.5 V, CIN = 1 mF, TAMB = 25°C unless otherwise specified.) 1.4 ENABLE THRESHOLD (V) ENABLE CURRENT (mA) 25 20 15 10 5 0 0 1 2 3 4 1.2 25°C 0.8 85°C 0.6 0.4 5 −40°C 1.0 3.0 3.5 4.0 4.5 5.0 ENABLE VOLTAGE (V) INPUT VOLTAGE (V) Figure 14. EN/PWM Pull−down Current vs. VEN/PWM Figure 15. EN/PWM Threshold vs. VIN Figure 16. Power Up from Shutdown Figure 17. Power Down Figure 18. PWM 200 Hz, 1% Duty Cycle http://onsemi.com 6 5.5 CAT4104 Table 5. PIN DESCRIPTIONS Name Pin SOIC 8−Lead Pin TDFN 8−Lead LED1 1 1 LED1 cathode terminal LED2 2 2 LED2 cathode terminal LED3 3 3 LED3 cathode terminal LED4 4 4 LED4 cathode terminal GND 5 5 and TAB EN/PWM 6 6 Device enable input and PWM control VIN 7 7 Device supply pin RSET 8 8 LED current set pin for the LED channels Function Ground reference Pin Function VIN is the supply pin for the device. A small 0.1 mF ceramic bypass capacitor is optional for noisy environments. Whenever the input supply falls below the under−voltage threshold, all LED channels are automatically disabled. EN/PWM is the enable and one wire dimming input for all LED channels. Guaranteed levels of logic high and logic low are set at 1.3 V and 0.4 V respectively. When EN/PWM is initially taken high, the device becomes enabled and all LED currents are set at a gain of 100 times the current in RSET. To place the device into zero current shutdown mode, the EN/PWM pin must be held low for 4 ms typical. LED1 to LED4 provide individual regulated currents for each of the LED cathodes. There pins enter a high impedance zero current state whenver the device is placed in shutdown mode. RSET pin is connected to an external resistor to set the LED channel current. The ground side of the external resistor should be star connected to the GND of the PCB. The pin source current mirrors the current to the LED sinks. The voltage at this pin is regulated to 1.2 V. GND is the ground reference for the device. The pin must be connected to the ground plane on the PCB. TAB (TDFN 8−Lead Only) 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. http://onsemi.com 7 CAT4104 Block Diagram VIN LED1 LED2 LED3 LED4 VIN EN/PWM 1.2 V Reference RSET 4 Current Sink Regulators Current Setting GND Figure 19. CAT4104 Functional Block Diagram Basic Operation The CAT4104 has four tightly matched current sinks to regulate LED current in each channel. The LED current in the four channels is mirrored from the current flowing through the RSET pin according to the following formula: I LED ^ 100 Tight current regulation for all channels is possible over a wide range of input voltages and LED voltages due to independent current sensing circuitry on each channel. Each LED channel needs a minimum of 400 mV headroom to sink constant regulated current up to 175 mA. If the input supply falls below 2 V, the under−voltage lockout circuit disables all LED channels. Any unused LED channels should be left open. For applications requiring more than 175 mA current, LED channels can be tied together to sink up to a total of 700 mA from the one device. The LED channels can withstand voltages up to 25 V. This makes the device ideal for driving long strings of high power LEDs from a high voltage source. 1.2 V R SET Table 6 shows standard resistor values for RSET and the corresponding LED current. Table 6. RSET RESISTOR SETTINGS LED Current [mA] RSET [kW] 20 6.34 60 2.10 100 1.27 175 0.768 http://onsemi.com 8 CAT4104 Application Information Single 12 V Supply Nightlight Detection The circuit shown in Figure 20 shows how to power the LEDs from a single 12 V supply using the CAT4104. Three external components are needed to create a lower voltage necessary for the VIN pin (below 5.5 V). The resistor R2 and zener diode Z provide a regulated voltage while the quiescent current runs through the N−Channel transistor M. The recommended parts are ON Semiconductor MM3Z6V2 zener diode (in SOD−323 package), and 2N7002L N−Channel transistor (in SOT23). The circuit shown in Figure 22 illustrates how to use the CAT4104 in an automatic night light application. The light sensor allows the CAT4104 to be disabled during the day and enabled during the night. Five external components are needed to properly configure the part for night detection. Resistor R3 limits the quiescent current through the N−Channel transistor M. Resistors R1 and R2 act as a voltage divider to create the required voltage to turn on transistor M, which disables the CAT4104. The recommended parts are ON Semiconductor 2N7002L N−Channel transistor (in SOT23) and the Microsemi LX1972 light sensor. For best performance, the LED light should not interfere with the light sensor. 12 V C2 1 mF R2 5 kW M Z 6.2 V 5V VIN LED1 CAT4104 LED2 EN/PWM LED3 C1 0.1 mF C2 1 mF VDD Light Sensor RSET LED4 GND R1 R1 100 kW VSS Figure 20. Single Supply Driving 12 LEDs R2 1 MW Daylight Detection The circuit in Figure 21 shows how to use CAT4104 in an automatic light sensor application. The light sensor allows the CAT4104 to be enabled during the day and disabled during the night. Two external components are required to configure the part for ambient light detection and conserve power. Resistor R1 sets the bias for the light sensor. The recommended part is Microsemi LX1972 light sensor. For best performance, the LED light should not interfere with the light sensor. VSS C1 0.1 mF OFF ON R1 OFF ON M R4 VIN LED1 CAT4104 LED2 LED3 EN/PWM RSET LED4 GND LED Current Derating The circuit shown in Figure 23 provides LED temperature derating to avoid over−driving the LED under high ambient temperatures, by reducing the LED current to protect the LED from over−heating. The positive thermo coefficient (PTC) thermistor RPTC is used for temperature sensing and should be located near the LED. As the temperature of RPTC increases, the gate voltage of the MOSFET M1 decreases. This causes the transistor M1 on−resistance to increase which results in a reduction of the LED current. The circuit is powered from a single VCC voltage of 5 V. The recommended parts are Vishay 70°C thermistor PTCSS12T071DTE and ON Semiconductor 2N7002L N−Channel transistor (in SOT23). The PCB and heatsink for the LED should be designed such that the LED current is constant within the normal temperature range. But as soon as the ambient temperature exceeds a max threshold, the LED current drops to protect the LEDs from overheating. R1 100 kW VDD Light Sensor C1 0.1 mF Figure 22. Nightlight Detection 5V C2 1 mF R3 100 kW VIN LED1 CAT4104 LED2 LED3 EN/PWM RSET LED4 GND Figure 21. Daylight Detection http://onsemi.com 9 CAT4104 VCC 5V C2 1 mF 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: RPTC VIN LED1 CAT4104 LED2 C1 0.1 mF T J + T AMB ) P D(q JC ) q CA) + T AMB ) P D q JA 350 mA When mounted on a double−sided printed circuit board with two square inches of copper allocated for “heat spreading”, the resulting qJA is about 90°C/W for the TDFN−8 package, and 160°C/W for the SOIC−8 package. For example, at 60°C ambient temperature, the maximum power dissipation for the TDFN−8 is calculated as follow: EN/PWM LED3 R1 1436 W LED4 RSET GND P Dmax + M1 R2 5 kW T Jmax * T AMB + 150 * 60 + 1 W q JA 90 Recommended Layout A small ceramic capacitor should be placed as close as possible to the driver VIN pin. The RSET resistor should have a Kelvin connection to the GND pin of the CAT4104. The board layout should provide good thermal dissipation through the PCB. In the case of the CAT4104VP2 in the TDFN package, a via can be used to connect the center tab to a large ground plane underneath as shown on Figure 24. Figure 23. LED Current Derating Power Dissipation The power dissipation (PD) of the CAT4104 can be calculated as follows: P D + (V IN I IN) ) S(V LEDN I LEDN) where VLEDN is the voltage at the LED pin, and ILEDN is the LED current. Combinations of high VLEDN voltage and high ambient temperature can cause the CAT4104 to enter thermal shutdown. In applications where VLEDN is high, a resistor can be inserted in series with the LED string to lower the power dissipation PD. Thermal dissipation of the junction heat consists primarily of two paths in series. The first path is the junction to the case (qJC) thermal resistance which is defined by the package style, and the second path is the case to ambient (qCA) thermal resistance, which is dependent on board layout. The overall junction to ambient (qJA) thermal resistance is equal to: Figure 24. CAT4104 Recommended Layout q JA + q JC ) q CA http://onsemi.com 10 CAT4104 PACKAGE DIMENSIONS SOIC 8, 150 mils CASE 751BD−01 ISSUE O SYMBOL E1 E MIN MAX A 1.35 1.75 A1 0.10 0.25 b 0.33 0.51 c 0.19 0.25 D 4.80 5.00 E 5.80 6.20 E1 3.80 4.00 1.27 BSC e PIN # 1 IDENTIFICATION NOM h 0.25 0.50 L 0.40 1.27 θ 0º 8º TOP VIEW D h A1 θ A c e b L END VIEW SIDE VIEW Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC MS-012. http://onsemi.com 11 CAT4104 PACKAGE DIMENSIONS TDFN8, 2x3 CASE 511AK−01 ISSUE A D A e b E2 E PIN#1 IDENTIFICATION A1 PIN#1 INDEX AREA D2 TOP VIEW SYMBOL MIN SIDE VIEW NOM A 0.70 0.75 0.80 0.00 0.02 0.05 A2 0.45 0.55 0.65 A2 0.20 REF A3 b 0.20 0.25 0.30 D 1.90 2.00 2.10 D2 1.30 1.40 1.50 E 2.90 3.00 3.10 E2 1.20 1.30 1.40 e L BOTTOM VIEW MAX A1 A3 FRONT VIEW 0.50 TYP 0.20 0.30 L 0.40 Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MO-229. http://onsemi.com 12 CAT4104 Example of Ordering Information (Note 6) 4. 5. 6. 7. 8. Prefix Device # Suffix CAT 4104 V −G T3 Company ID (Optional) Product Number 4104 Package V: SOIC VP2: TDFN Lead Finish G: NiPdAu Tape & Reel (Note 8) T: Tape & Reel 3: 3,000 / Reel All packages are RoHS−compliant (Lead−free, Halogen−free). The standard plated finish is NiPdAu. The device used in the above example is a CAT4104V−GT3 (SOIC, NiPdAu, Tape & Reel, 3,000/Reel). For additional temperature options, please contact your nearest ON Semiconductor Sales office. 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. 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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 http://onsemi.com 13 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative CAT4104/D