CAT3644 4-Channel Ultra High Efficiency LED Driver Description Applications • • • • LCD Display Backlight Cellular Phones Digital Still Cameras Handheld Devices NC NC GND LED1 1 LED2 C2− LED3 C2+ LED4 C1− RSET C1+ VIN High Efficiency 1.33x Charge Pump Charge Pump: 1x, 1.33x, 1.5x, 2x Drives up to 4 LEDs at 25 mA Each 1−wire EZDim LED Current Programming Power Efficiency up to 92% Low Noise Input Ripple in All Modes “Zero” Current Shutdown Mode Soft Start and Current Limiting Short Circuit Protection Thermal Shutdown Protection 3 mm x 3 mm, 16−pad TQFN Package These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant PIN CONNECTIONS NC • • • • • • • • • • • • TQFN−16 HV3 SUFFIX CASE 510AD VOUT Features http://onsemi.com EN/DIM The CAT3644 is a high efficiency fractional charge pump that can drive up to four LEDs programmable by a one wire digital interface. The inclusion of a 1.33x fractional charge pump mode increases device efficiency by up to 10% over traditional 1.5x charge pumps with no added external capacitors. Low noise input ripple is achieved by operating at a constant switching frequency which allows the use of small external ceramic capacitors. The multi−fractional charge pump supports a wide range of input voltages from 2.5 V to 5.5 V. The EN/DIM logic input functions as a chip enable and a digital dimming interface for current setting of all LEDs. Six different current ratios are available via the interface. The device is available in the tiny 16−pad TQFN 3 mm x 3 mm package with a max height of 0.8 mm. ON Semiconductor’s 1.33x charge pump switching architecture is patented. (Top View) MARKING DIAGRAMS JAAG AXXX YWW JAAH AXXX YWW JAAG = CAT3644HV3−T2 JAAH = CAT3644HV3−GT2 A = Assembly Location XXX = Last Three Digits of Assembly Lot Number Y = Production Year (Last Digit) WW = Production Week (Two Digits) ORDERING INFORMATION Device Package CAT3644HV3−T2 (Note 1) TQFN−16 (Pb−Free) CAT3644HV3−GT2 (Note 2) TQFN−16 (Pb−Free) Shipping† 2000 / Tape & Reel 1. Matte−Tin Plated Finish (RoHS−compliant). 2. NiPdAu Plated Finish (RoHS−compliant). †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D. © Semiconductor Components Industries, LLC, 2014 August, 2014 − Rev. 8 1 Publication Order Number: CAT3644/D CAT3644 1 mF VIN 2.4 V to 5.5 V CIN C1+ C1− C2+ C2− VOUT VIN CAT3644 1 mF 1−Wire EZDim Programming 1 mF EN/DIM RSET GND 4.02 kΩ VOUT COUT 1 mF LED1 LED2 LED3 LED4 20 mA Figure 1. Typical Application Circuit Table 1. ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit VIN, LEDx, C1±, C2±, EN/DIM voltage 6 V VOUT voltage 7 V Storage Temperature Range −65 to +160 _C Junction Temperature Range −40 to +150 _C Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. Table 2. RECOMMENDED OPERATING CONDITIONS Parameter Rating Unit VIN 2.5 to 5.5 V Ambient Temperature Range −40 to +85 _C ILED per LED pin up to 30 mA LED Forward Voltage Range 1.3 to 4.3 V Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability. NOTE: Typical application circuit with external components is shown above. http://onsemi.com 2 CAT3644 Table 3. ELECTRICAL OPERATING CHARACTERISTICS (over recommended operating conditions unless specified otherwise) VIN = 3.6 V, EN = High, TAMB = 25°C. Symbol Name Conditions IQ Quiescent Current 1x mode, no load 1.33x mode, no load 1.5x mode, no load 2x mode, no load IQSHDN Shutdown Current VEN = 0 V ILED−ACC LED Current Accuracy (ILEDAVG – INOMINAL) / INOMINAL RSET = 5 kW ILED−DEV LED Channel Matching (ILED − ILEDAVG) / ILEDAVG Min Typ Max 1.0 1.7 2.2 2.4 mA 1 mA ±2 % ±1.5 % VRSET RSET Regulated Voltage ROUT Output Resistance (open loop) 1x mode 1.33x mode, VIN = 3 V 1.5x mode, VIN = 2.7 V 2x mode, VIN = 2.4 V FOSC Charge Pump Frequency 1.33x and 2x mode 1.5x mode ISC_MAX Output short circuit Current Limit VOUT < 0.5 V 50 mA IIN_MAX Input Current Limit VOUT > 1 V 250 mA LEDTH 1x to 1.33x or 1.33x to 1.5x or 1.5x to 2x Transition Thresholds at any LED pin 130 mV 1x Mode Transition Hysteresis 400 mV Transition Filter Delay 500 ms 100 kW V V VHYS TDF REN/DIM VHI VLO 0.58 Units EN/DIM Pin − Internal Pull−down Resistor − Logic High Level − Logic Low Level 0.6 0.62 0.8 5 5 10 0.8 1 1 1.3 V W 1.3 1.6 1.3 0.4 MHz TSD Thermal Shutdown 150 °C THYS Thermal Hysteresis 20 °C VUVLO Undervoltage lockout (UVLO) threshold 1.6 1.8 2.0 V Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. http://onsemi.com 3 CAT3644 Table 4. RECOMMENDED EN/DIM TIMING (For 2.4 V ≤ VIN ≤ 5.5 V, over full ambient temperature range −40°C to +85°C.) Name Symbol TSETUP Conditions Min Typ Max Units EN/DIM setup from shutdown 10 TLO EN/DIM program low time 0.2 THI EN/DIM program high time 0.2 ms EN/DIM low time to shutdown 1.5 ms TPWRDWN TLED LED current settling time ms 100 40 TSETUP ms TPWRDWN THI EN/DIM TLED TLO 100% 100% 50% LED Current Shutdown 25% 12.5% 6.25% 3.12% Figure 2. EN/DIM Digital Dimming Timing Diagram LED Current Setting The nominal LED current is set by the external resistor connected between the RSET pin and ground. Table 5 lists standard resistor values for several LED current settings. Table 5. RESISTOR RSET AND LED CURRENT LED Current (mA) RSET (kW) 2 40.0 5 15.8 10 7.87 15 5.23 20 4.02 25 3.16 30 2.67 http://onsemi.com 4 ms Shutdown CAT3644 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), CIN = COUT = C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.) 100 100 1.33x VF = 3.3 V 1.5x 90 VF = 3.3 V 90 1x EFFICIENCY (%) EFFICIENCY (%) 1x 2x 80 70 60 50 40 4.5 4.0 3.5 3.0 2.5 4.0 3.8 3.6 3.4 3.2 INPUT VOLTAGE (V) Figure 3. Efficiency vs. Input Voltage Figure 4. Efficiency vs. Li−Ion Voltage 3.0 4 QUIESCENT CURRENT (mA) QUIESCENT CURRENT (mA) 4.2 INPUT VOLTAGE (V) 3 2 1 LEDs Off 5.5 5.0 4.5 4.0 3.5 3.0 2.5 3 2x 1.5x 1.33x 2 1x 1 0 −40 2.0 0 40 80 120 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 5. Quiescent Current vs. Input Voltage Figure 6. Quiescent Current vs. Temperature 10 10 8 VF = 3.3 V LED CURRENT VARIATION (%) LED CURRENT VARIATION (%) 60 40 2.0 VF = 3.3 V 6 4 2 0 −2 −4 −6 −8 −10 70 50 4 0 1.33x 80 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 8 VF = 3.3 V 6 4 2 0 −2 −4 −6 −8 −10 −40 0 40 80 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 7. LED Current Change vs. Input Voltage Figure 8. LED Current Change vs. Temperature http://onsemi.com 5 120 CAT3644 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), CIN = COUT = C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.) 12 1.2 OUTPUT RESISTANCE (W) SWITCHING FREQUENCY (MHz) 1.3 1.5x Mode 1.1 1.0 0.9 1.33x, 2x Mode 0.8 0.7 −40 0 40 80 10 8 6 1.33x 1.5x 4 2 0 120 2x 1x 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 TEMPERATURE (°C) INPUT VOLTAGE (V) Figure 9. Switching Frequency vs. Temperature Figure 10. Output Resistance vs. Input Voltage Figure 11. Power Up in 1x Mode Figure 12. Power Up in 1.33x Mode Figure 13. Power Up in 1.5x Mode Figure 14. Power Up in 2x Mode http://onsemi.com 6 CAT3644 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), CIN = COUT = C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.) Figure 15. Power Up Delay (1x Mode) Figure 16. Power Down Delay (1x Mode) Figure 17. Operating Waveforms in 1x Mode Figure 18. Switching Waveforms in 1.33x Mode Figure 19. Switching Waveforms in 1.5x Mode Figure 20. Switching Waveforms in 2x Mode http://onsemi.com 7 CAT3644 TYPICAL PERFORMANCE CHARACTERISTICS (VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), CIN = COUT = C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.) 40 4.0 1x Mode LED CURRENT (mA) 3.0 2.5 2.0 1.5 1.0 30 20 10 0.5 0 0 100 200 300 0 400 0 50 100 150 200 250 OUTPUT CURRENT (mA) LED PIN VOLTAGE (mV) Figure 21. Foldback Current Limit Figure 22. LED Current vs. LED Pin Voltage 300 50 LED CURRENT (mA) OUTPUT VOLTAGE (V) 3.5 40 30 20 10 0 1 10 RSET RESISTANCE (kW) Figure 23. Dimming Waveform Figure 24. LED Current vs. RSET http://onsemi.com 8 100 CAT3644 Table 6. PIN DESCRIPTION Pin # Name Function 1 LED2 LED2 cathode terminal. 2 LED3 LED3 cathode terminal. 3 LED4 LED4 cathode terminal. 4 RSET Connect resistor RSET to set the LED current. 5 EN/DIM 6 VOUT 7 NC Not connected inside the package. 8 VIN Charge pump input, connect to battery or supply. 9 C1+ Bucket capacitor 1 Positive terminal 10 C1− Bucket capacitor 1 Negative terminal 11 C2+ Bucket capacitor 2 Positive terminal 12 C2− Bucket capacitor 2 Negative terminal 13 NC Not connected inside the package. 14 NC Not connected inside the package. 15 GND Ground Reference 16 LED1 LED1 cathode terminal. TAB GND Connect to GND on the PCB. Device enable (active high) and Dimming Control. Charge pump output connected to the LED anodes. 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 2.5 V to 5.5 V. Whenever the input supply falls below the under−voltage threshold (1.8 V), all the LED channels are disabled and the device enters shutdown mode. EN/DIM is the enable and one wire dimming input for all LED channels. 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 are set to the full scale according to the resistor RSET. To place the device into “zero current” shutdown mode, the EN/DIM pin must be held low for at least 1.5 ms. 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 ceramic bucket capacitor C1. C2+, C2− are connected to each side of the ceramic bucket capacitor C2. LED1 to LED4 provide the internal regulated current source for each of the LED cathodes. These pins enter high−impedance zero current state whenever the device is placed in shutdown mode. 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. RSET is connected to the resistor (RSET) to set the full scale current for the LEDs. The voltage at this pin regulated to 0.6 V. The ground side of the external resistor should be star connected back to the GND of the PCB. In shutdown mode, RSET becomes high impedance. http://onsemi.com 9 CAT3644 Block Diagram C1− VIN C1+ C2− C2+ VOUT 1x mode (LDO) 4/3x, 3/2x, 2x Charge Pump Mode Control 1, 1.3 MHz Oscillator EN/DIM LED1 100 kΩ LED2 LED3 LED4 Serial Interface Reference Voltage Registers Current Setting DAC LED Channel Current Regulators RSET GND Figure 25. CAT3644 Functional Block Diagram Basic Operation At power−up, the CAT3644 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 into 1.33x mode (after a fixed delay time of about 400 ms). In 1.33x mode, the output voltage is approximately equal to 1.33 times the input supply voltage (less any internal voltage losses). This sequence repeats in the 1.33x and 1.5x mode until the driver enters the 2x mode. In 1.5x mode, the output voltage is approximately equal to 1.5 times the input supply voltage. While in 2x mode, the output is approximately equal to 2 times the input supply voltage. If the device detects a sufficient input voltage is present to drive all LED currents in 1x mode, it will change automatically back to 1x mode. This only applies for changing back to the 1x mode. The difference between the input voltage when exiting 1x mode and returning to 1x mode is called the 1x mode transition hysteresis (VHYS) and is about 500 mV. http://onsemi.com 10 CAT3644 LED Current Selection input signal, as shown on Figure 26. On each consecutive pulse rising edge, the LED current is divided by half to 50%, then 25%, 12.5%, 6.25% and 3.125% dimming levels. Pulses faster than the minimum TLO may be ignored and filtered by the device. Pulses longer than the maximum TLO may shutdown the device. The LED driver enters a “zero current” shutdown mode if EN/DIM is held low for 1.5 ms or more. At power−up, the initial LED current is set to full scale (100% brightness) by the external resistor RSET as follows: LED current + 132 0.6 V R SET The EN/DIM pin has two primary functions. One function enables and disables the device. The other function is LED current dimming with six different levels by pulsing the THI TSETUP TPWRDWN EN/DIM TLED TLO 100% 100% 50% LED Current Shutdown 25% 12.5% 6.25% 3.12% Shutdown Figure 26. EN/DIM Digital Dimming Timing Diagram Table 7. LED CURRENT DIMMING LEVELS EN/DIM # of Pulses * RSET Gain LED Current EN = High 132 132 x 0.6 V / RSET 1st 66 66 x 0.6 V / RSET 2nd 33 33 x 0.6 V / RSET 3rd 16.5 16.5 x 0.6 V / RSET 4th 8.25 8.25 x 0.6 V / RSET 5th 4.125 4.125 x 0.6 V / RSET 6th 132 132 x 0.6 V / RSET xth Device cycling through gain selection GAIN x 0.6 V / RSET * The gain is changed on the rising edges of the EN/DIM input. http://onsemi.com 11 CAT3644 Unused LED Channels LED Selection For applications not requiring all the channels, it is recommended the unused LED pins be tied directly to VOUT (see Figure 27). LEDs with forward voltages (VF) ranging from 1.3 V to 4.3 V may be used. Selecting LEDs with lower VF is recommended in order to improve the efficiency by keeping the driver in 1x mode longer as the battery voltage decreases. For example, if a white LED with a VF of 3.3 V is selected over one with VF of 3.5 V, the driver will stay in 1x mode for lower supply voltage of 0.2 V. This helps improve the efficiency and extends battery life. 1 mF VIN C1+ VIN C2− VOUT COUT CIN CAT3644 1 mF ENABLE DIMMING C1− C2+ 1 mF LED1 EN/DIM RSET GND RSET External Components The driver requires four external 1 mF ceramic capacitors for decoupling input, output, and for the charge pump. Both capacitors type X5R and X7R are recommended for the LED driver application. In all charge pump modes, 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 operates in linear mode and does not introduce switching noise back onto the supply. 1 mF LED2 LED3 LED4 Figure 27. Application with 3 LEDs Recommended Layout Protection Mode In charge pump mode, the driver switches internally at a high frequency. 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 TQFN exposed pad (TAB) must be connected to the ground plane underneath. The use of multiple via improves the package heat dissipation. If an LED is disconnected, the driver senses that and automatically ignores that channel. When all LEDs are disconnected, the driver goes to 1x mode where the output is equal to the input voltage. As soon as the output exceeds about 6 V, the driver resets itself and reevaluate the mode. If the die temperature exceeds +150°C, the driver will enter a thermal protection shutdown mode. When the device temperature drops by about 20°C, the device will resume normal operation. GND Pin1 C2 EN/DIM C1 RSET VIN GND COUT CIN GND Figure 28. Recommended Layout http://onsemi.com 12 CAT3644 PACKAGE DIMENSIONS TQFN16, 3x3 CASE 510AD ISSUE A A D e b L E2 E PIN#1 ID PIN#1 INDEX AREA A1 TOP VIEW SIDE VIEW SYMBOL MIN NOM MAX A 0.70 0.75 0.80 A1 0.00 0.02 0.05 A3 BOTTOM VIEW 0.20 REF b 0.18 0.25 0.30 D 2.90 3.00 3.10 D2 1.40 −−− 1.80 E 2.90 3.00 3.10 E2 1.40 −−− 1.80 e L D2 A A3 A1 FRONT VIEW 0.50 BSC 0.30 0.40 0.50 Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MO-220. ON Semiconductor and the are registered trademarks of Semiconductor Components Industries, LLC (SCILLC) or its subsidiaries in the United States and/or other countries. SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. 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] 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: 81−3−5817−1050 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 CAT3644/D