CAT3614 4-Channel 1-Wire LED Driver in 3 x 3 mm Package Description The CAT3614 is a high efficiency 1x/1.5x fractional charge pump with programmable dimming current in four LED channels. To ensure uniform brightness in LCD backlight applications, each LED channel delivers an accurate regulated current. Low noise and input ripple is achieved by operating at a constant switching frequency of 1 MHz which allows the use of small external ceramic capacitors. The 1x/1.5x fractional charge pump supports a wide range of input voltages from 3 V to 5.5 V with efficiency up to 91%, and is ideal for Li−Ion battery powered devices. The EN/DIM logic input provides a 1−wire EZDimt interface for dimming control of the LEDs. When enabled, a series of clock pulses reduces the LED brightness in 1 mA steps on each negative going edge. Currents from 0 mA to 31 mA are supported. The device is available in the tiny 12−pad TDFN 3 x 3 mm package with a max height of 0.8 mm. C1+ EN/DIM Features C1− LED4 C2− LED3 C2+ LED2 GND LED1 • • • • • • • • • • • • • Drives up to 4 LED Channels 1−wire EZDimt Programmable LED Current Accurate 1 mA Dimming Level Power Efficiency up to 91% Fractional Pump 1x/1.5x Low Noise Input Ripple Fixed High Frequency Operation 1 MHz “Zero” Current Shutdown Mode Soft Start and Current Limiting Short Circuit Protection Thermal Shutdown Protection TDFN 12−pad 3 mm x 3 mm Package These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant Applications • • • • http://onsemi.com TDFN−12 HV2 SUFFIX CASE 511AN PIN CONNECTIONS 1 VIN VOUT (Top View) MARKING DIAGRAM HAAA AXXX YWW HAAC AXXX YWW HAAA = CAT3614HV2-T2 HAAC = CAT3614HV2-GT2 A = Assembly Location XXX = Last Three Digits of Assembly Lot Number Y = Production Year (Last Digit) WW = Production Week (Two Digit) ORDERING INFORMATION LCD Display Backlight Cellular Phones Digital Still Cameras Handheld Devices Device Package Shipping CAT3614HV2−T2 (Note 1) TDFN−12 (Pb−Free) 2,000/ Tape & Reel CAT3614HV2−GT2 (Note 2) TDFN−12 (Pb−Free) 2,000/ Tape & Reel 1. Matte−Tin Plated Finish (RoHS−compliant). 2. NiPdAu Plated Finish (RoHS−compliant). © Semiconductor Components Industries, LLC, 2010 April, 2010 − Rev. 2 1 Publication Order Number: CAT3614/D CAT3614 1 mF VIN 3 V to 5.5 V CIN C1+ C1− C2+ C2− VIN VOUT CAT3614 1 mF ENABLE/ DIMMING 1 mF EN/DIM GND LED1 LED2 LED3 LED4 VOUT COUT 1 mF 20 mA Figure 1. Typical Application Circuit NOTE: Unused LED channels must be connected to VOUT. Table 1. ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit VIN, LEDx voltage 6 V VOUT, C1±, C2± voltage 7 V EN/DIM voltage VIN + 0.7 V 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 Range Unit 3 to 5.5 V −40 to +85 °C ILED per LED pin 0 to 31 mA Total Output Current 0 to 124 mA VIN Ambient Temperature Range NOTE: Typical application circuit with external components is shown above. http://onsemi.com 2 CAT3614 Table 3. ELECTRICAL OPERATING CHARACTERISTICS VIN = 3.6 V, EN = High, ambient temperature of 25°C (over recommended operating conditions unless specified otherwise). Symbol Parameter Conditions Min Typ Max Unit 0.3 1 0.5 3 1 8 mA IQ Quiescent Current 1x mode, no load 1.5x mode, no load IQSHDN Shutdown Current VEN = 0 V 1 mA ILED−ACC LED Current Accuracy 1 mA ≤ ILED ≤ 31 mA ±3 ±8 % ILED−DEV LED Channel Matching (ILED − ILEDAVG) / ILEDAVG ±3 ±7 % ROUT Output Resistance (open loop) 1x mode, IOUT = 100 mA 1.5x mode, IOUT = 100 mA 0.4 2.6 1 7 W FOSC Charge Pump Frequency 0.8 1 1.3 MHz ISC_MAX Output short circuit Current Limit VOUT < 0.5 V 30 60 100 mA IIN_MAX Input Current Limit 1x mode, VOUT > 1 V 200 300 600 mA IEN/DIM VHI VLO EN/DIM Pin − Input Leakage − Logic High Level − Logic Low Level −1 1.3 1 0.4 mA V V TSD Thermal Shutdown 145 165 175 °C THYS Thermal Hysteresis 10 20 30 °C Undervoltage lock out (UVLO) threshold 1.7 2 2.4 V VUVLO Table 4. RECOMMENDED EN/DIM TIMING (For 3 V ≤ VIN ≤ 5.5 V, over full ambient temperature range −40 to +85°C.) Symbol TSETP Parameter Conditions Min Typ Max Unit EN/DIM setup from shutdown 10 TLO EN/DIM program low time 0.3 THI EN/DIM program high time 0.3 ms EN/DIM low time to shutdown 1.5 ms TOFF TD TDEC ms 200 ms LED current enable 40 ms LED current decrement 0.1 ms TSETP THI TOFF EN/DIM TD TLO TDEC 31 mA 30 mA 29 mA 31 mA LED Current 1 mA Shutdown 0 mA Figure 2. LED Dimming Timing Diagram http://onsemi.com 3 Shutdown CAT3614 TYPICAL CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25°C unless otherwise specified.) 100 100 20 mA per LED 90 90 EFFICIENCY (%) EFFICIENCY (%) 1x mode 80 70 10 mA per LED 60 50 40 4.0 3.8 3.6 3.4 3.2 0 25 50 75 100 Figure 3. Efficiency vs. Input Voltage (4 LEDs) Figure 4. Efficiency vs. Total LED Current (4 LEDs) 125 0.8 QUIESCENT CURRENT (mA) QUIESCENT CURRENT (mA) VIN = 3.2 V (1.5x Mode) TOTAL LED CURRENT (mA) 0.4 4 LEDs OFF 0.2 3.0 3.2 3.4 3.6 3.8 4.0 0.6 0.4 4 LEDs OFF 0.2 0 −40 4.2 0 40 80 120 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 5. Quiescent Current vs. Input Voltage (1x Mode) Figure 6. Quiescent Current vs. Temperature (1x Mode) 6 QUIESCENT CURRENT (mA) 6 QUIESCENT CURRENT (mA) 60 INPUT VOLTAGE (V) 0.6 5 4 3 2 4 LEDs OFF 1 0 70 40 3.0 0.8 0 80 50 1.5x mode 4.2 VIN = 4 V (1x Mode) 3.0 3.2 3.4 3.6 3.8 4.0 5 4 3 2 4 LEDs OFF 1 0 −40 4.2 0 40 80 120 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 7. Quiescent Current vs. Input Voltage (1.5x Mode) Figure 8. Quiescent Current vs. Temperature (1.5x Mode) http://onsemi.com 4 CAT3614 TYPICAL CHARACTERISTICS 5 4 4 3 1x Mode 2 1 0 −1 1.5x Mode −2 −3 −4 −5 CLOCK FREQUENCY (MHz) LED CURRENT CHANGE (%) 5 3.0 3.2 3.4 3.6 3.8 4.0 2 1 0 −1 −2 −3 −4 4.2 20 40 60 Figure 9. LED Current Change vs. Input Voltage Figure 10. LED Current Change vs. Temperature 1.2 1.2 1.1 1.0 4 LEDs at 20 mA 0.9 0.8 3.2 3.4 3.6 3.8 80 1.1 1.0 0.9 0.8 0.7 −40 4.0 0 40 80 120 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 11. Oscillator Frequency vs. Input Voltage Figure 12. Oscillator Frequency vs. Temperature 4.0 OUTPUT RESISTANCE (W) 1.0 0.8 0.6 0.4 0.2 0 0 TEMPERATURE (°C) 1.3 3.0 −20 INPUT VOLTAGE (V) 1.3 0.7 OUTPUT RESISTANCE (W) 3 −5 −40 CLOCK FREQUENCY (MHz) LED CURRENT CHANGE (%) (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25°C unless otherwise specified.) 3.0 3.2 3.4 3.6 3.8 4.0 3.5 3.0 2.5 2.0 1.5 1.0 4.2 3.0 3.2 3.4 3.6 3.8 4.0 4.2 INPUT VOLTAGE (V) INPUT VOLTAGE (V) Figure 13. Output Resistance vs. Input Voltage (1x Mode) Figure 14. Output Resistance vs. Input Voltage (1.5x Mode) http://onsemi.com 5 CAT3614 TYPICAL CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25°C unless otherwise specified.) Figure 15. Power Up with 4 LEDs at 15 mA (1x Mode) Figure 16. Power Up with 4 LEDs at 15 mA (1.5x Mode) Figure 17. Enable Power Down Delay (1x Mode) Figure 18. Enable Power Down Delay (1.5x Mode) Figure 19. Switching Waveforms in 1.5x Mode Figure 20. Operating Waveforms in 1x Mode http://onsemi.com 6 CAT3614 TYPICAL CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25°C unless otherwise specified.) Figure 21. Enable and Output Current Dimming Waveforms Figure 22. Line Transient Response (3.6 V to 5.5 V) 1x Mode 200 200 VIN = 3.5 V 160 VIN = 3.5 V MINIMUM TIME (nS) MINIMUM TIME (nS) 160 120 80 VIN = 4.2 V 40 0 −40 0 40 80 0 −40 120 0 40 80 TEMPERATURE (°C) TEMPERATURE (°C) Figure 23. Enable High Minimum Program Time vs. Temperature Figure 24. Enable Low Minimum Program Time vs. Temperature 120 4.0 3.5 OUTPUT VOLTAGE (V) 1.0 ENABLE VOLTAGE (V) VIN = 4.2 V 80 40 1.2 0.8 0.6 0.4 0.2 0 −40 120 3.0 1x Mode 2.5 VIN = 3.5 V 2.0 1.5 1.0 0.5 0 40 80 0 120 0 100 200 300 TEMPERATURE (°C) OUTPUT CURRENT (mA) Figure 25. Enable Voltage Threshold vs. Temperature Figure 26. Foldback Current Limit http://onsemi.com 7 400 CAT3614 Table 5. PIN DESCRIPTIONS Pin # Name Function 1 VIN Supply voltage. 2 C1+ Bucket capacitor 1 terminal 3 C1− Bucket capacitor 1 terminal 4 C2− Bucket capacitor 2 terminal 5 C2+ Bucket capacitor 2 terminal 6 GND Ground reference 7 LED1 LED1 cathode terminal (if not used, connect to VOUT) (Note 3) 8 LED2 LED2 cathode terminal (if not used, connect to VOUT) (Note 3) 9 LED3 LED3 cathode terminal (if not used, connect to VOUT) (Note 3) 10 LED4 LED4 cathode terminal (if not used, connect to VOUT) (Note 3) 11 EN/DIM 12 VOUT TAB TAB Device enable (active high) and dimming control input Charge pump output connected to the LED anodes Connect to GND on the PCB 3. LED1, LED2, LED3, LED4 pins should not be left floating. They should be connected to the LED cathode, or tied to VOUT pin if not used. Pin Function VIN is the supply pin for the charge pump. A small 1 mF ceramic bypass capacitor is required between the VIN pin and ground near the device. The operating input voltage range is from 2.2 V to 5.5 V. Whenever the input supply falls below the undervoltage threshold (2 V) all LEDs channels will be automatically disabled. EN/DIM is the enable and dimming control logic 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/DIM is initially taken high, the device becomes enabled and all LED currents remain at 0 mA. The falling edge of the first pulse applied to EN/DIM sets all LED currents to their full scale of 31 mA. On each consecutive falling edge of the pulse applied to EN/DIM, the LED current is decreased by 1 mA step. On the 32nd pulse, the LED current is set to zero. The next pulse on EN/DIM resets the current back to their full scale of 31 mA. To place the device into zero current shutdown mode, the EN/DIM pin must be held low for 1.5 ms or more. VOUT is the charge pump output that is connected to the LED anodes. A small 1 mF ceramic bypass capacitor is required between the VOUT pin and ground near the device. GND is the ground reference for the charge pump. The pin must be connected to the ground plane on the PCB. C1+, C1− are connected to each side of the 1 mF ceramic bucket capacitor C1. C2+, C2− are connected to each side of the 1 mF ceramic bucket capacitor C2. LED1 to LED4 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 four LEDs, all unused channels should be wired directly to VOUT. This ensures the channel is automatically disabled dissipating less than 200 mA. 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. http://onsemi.com 8 CAT3614 Block Diagram 1 mF C1− C1+ VIN 1 mF C2− C2+ VOUT 1x mode (LDO) 1.5x Charge Pump CIN 1 mF 1 MHz Oscillator EN/DIM Mode Control LED1 LED2 Reference Voltage LED3 LED4 Current Setting DAC LED Channel Current Regulators Serial Interface Registers GND Figure 27. CAT3614 Functional Block Diagram Basic Operation At power−up, the CAT3614 starts operating in 1x mode where the output will be approximately equal to the input supply voltage (less any internal voltage losses). If the output voltage is sufficient to regulate all LED currents the device remains in 1x operating mode. If the input voltage is insufficient or falls to a level where the regulated currents cannot be maintained, the device automatically switches (after a fixed delay of 400 ms) into 1.5x mode. In 1.5x mode, the output is approximately equal to 1.5 times the input supply voltage (less any internal voltage losses). The above sequence is repeated each and every time the chip is powered−up or is taken out of shutdown mode (via EN/DIM pin). http://onsemi.com 9 CAT3614 LED Current Setting temperature drops down by about 20°C, the device resumes normal operation. Figure 2 shows the timing diagram necessary at the EN/DIM input for setting the LED currents. The EN/DIM set up time requires the signal to be held high for 10 ms or longer to ensure the initialization of the driver at power−up. Each subsequent pulse on the EN/DIM (300 ns to 200 ms pulse duration) steps down the LED current from full scale of 31 mA to zero with a 1 mA resolution. Consecutive pulses should be separated by 300 ns or longer. Pulsing beyond the 0 mA level restores the current level back to full scale and the cycle repeats. Pulsing frequencies from 5 kHz up to 1 MHz can be supported during dimming operations. When the EN/DIM is held low for 1.5 ms or more, the CAT3614 enters the shutdown mode and draws “zero” current. For applications with three LEDs or less, any unused LED pins should be tied to VOUT, as shown on Figure 28. External Components The driver requires a total of four external 1 mF 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 is kept very low by design, and an input bypass capacitor of 1 mF is sufficient. In 1x mode, the device operating in linear mode does not introduce switching noise back onto the supply. Recommended Layout In 1.5x charge pump mode, the driver switches internally at a high frequency of 1 MHz. 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 vias. A copper area matching the TDFN exposed pad (GND) must be connected to the ground plane underneath. The use of multiple vias improves the package heat dissipation. Protection Mode If an LED becomes open−circuit, the output voltage VOUT is internally limited to about 5.5 V. This is to prevent the output pin from exceeding its absolute maximum rating. The driver enters a thermal shutdown mode as soon as the die temperature exceeds about +165°C. When the device 1 mF VIN 3 V to 5.5 V CIN 1 mF ENABLE/ DIMMING C1+ C1− C2+ VIN 1 mF 1 mF C2− VIN VOUT COUT CAT3614 LED1 LED2 EN/DIM GND 1 mF LED3 LED4 3 V to 5.5 V CIN 1 mF ENABLE/ DIMMING C1+ C1− C2+ C2− VOUT VIN COUT LED1 LED2 EN/DIM LED3 LED4 Figure 29. Single Flash LED Application http://onsemi.com 10 Flash LED 1 mF CAT3614 GND Figure 28. Three LED Application 1 mF 120 mA CAT3614 PACKAGE DIMENSIONS TDFN12, 3x3 CASE 511AN−01 ISSUE A D A e b L E E2 PIN#1 ID PIN#1 INDEX AREA A1 SIDE VIEW TOP VIEW SYMBOL MIN NOM MAX A 0.70 0.75 0.80 A1 0.00 0.02 0.05 A3 0.178 0.203 0.228 b 0.18 0.23 0.30 D 2.90 3.00 3.10 D2 2.30 2.40 2.50 E 2.90 3.00 3.10 E2 1.55 1.70 1.75 e BOTTOM VIEW A A3 A1 FRONT VIEW RECOMMENDED LAND PATTERN R e M 0.45 BSC L 0.30 0.40 0.50 M 0.25 0.30 0.35 N 0.60 0.70 0.80 P 2.70 3.00 3.10 R D2 N P 2.25 TYP E2 Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MO-229. D2 http://onsemi.com 11 CAT3614 Example of Ordering Information (Note 6) 4. 5. 6. 7. 8. Prefix Device # Suffix CAT 3614 HV2 −G T2 Company ID (Optional) Product Number 3614 Package HV2: TDFN 3 x 3 mm Lead Finish Blank: Matte−Tin (Note 7) G: NiPdAu Tape & Reel (Note 8) T: Tape & Reel 2: 2,000 / Reel All packages are RoHS−compliant (Lead−free, Halogen−free). The standard lead finish is NiPdAu. The device used in the above example is a CAT3614HV2−GT2 (TDFN, NiPdAu Plated Finish, Tape & Reel, 2,000/Reel). For additional package 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. EZDim is a trademark of Semiconductor Components Industries, LLC. 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. 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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] 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 http://onsemi.com 12 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative CAT3614/D