CAT3612 Programmable 300 mA Camera Flash LED Driver Description The CAT3612 is a high−efficiency 1x/1.5x fractional charge pump with programmable current in two LED channels. Each channel delivers accurate regulated current up to 150 mA and make CAT3612 ideal for driving one or two flash LEDs. Low noise operation 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 90%, 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, pulsing the EN/DIM reduces the LED current on each negative edge in 31 linear steps from 150 mA down to zero current. The device is available in the tiny 12−lead thin DFN 3 mm x 3 mm package with a max height of 0.8 mm. C1+ N/C Features C1− EN/DIM C2− N/C GND C2+ LED1 LED2 • • • • • • • • • • • • • • Dual Matched Regulated LED Channels 300 mA Output Current (150 mA per Channel) 1−wire EZDimt Programmable LED Current 32 Accurate Dimming Levels Power Efficiency up to 90% 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 12−lead TDFN 3 mm x 3 mm Package These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant http://onsemi.com TDFN−12 HV2 SUFFIX CASE 511AN PIN CONNECTIONS 1 VIN VOUT (Top View) MARKING DIAGRAM HAAD AXXX YWW HAAF AXXX YWW HAAD = CAT3612HV2-T2 HAAF = CAT3612HV2-GT2 A = Assembly Location XXX = Last Three Digits of Assembly Lot Number Y = Production Year (Last Digit) WW = Production Week (Two Digit) ORDERING INFORMATION Applications Device • Camera Flash • Cellular Phones • Digital Still Cameras Package Shipping CAT3612HV2−T2 (Note 1) TDFN−12 (Pb−Free) 2,000/ Tape & Reel CAT3612HV2−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: CAT3612/D CAT3612 1 mF C1+ VIN 3 V to 5.5 V CIN 1 mF C1− C2+ C2− VOUT VIN 2.2 mF CAT3612 2.2 mF COUT LED1 ENABLE/ DIMMING EN/DIM Flash LED 300 mA LED2 GND Figure 1. Typical Application Circuit NOTE: Unused LED channel must be connected to VOUT Table 1. ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit VIN, LED1, LED2 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 150 mA Total Output Current 0 to 300 mA VIN Ambient Temperature Range NOTE: Typical application circuit with external components is shown above. http://onsemi.com 2 CAT3612 Table 3. ELECTRICAL OPERATING CHARACTERISTICS (over recommended operating conditions unless specified otherwise) VIN = 3.6 V, EN = High, ambient temperature of 25°C. Symbol Parameter IQ Quiescent Current IQSHDN Shutdown Current Conditions Min Typ 1x mode, no load 1.5x mode, no load Max 0.5 3 VEN = 0 V Unit mA 1 mA ILED−ACC LED Current Accuracy 5 mA ≤ ILED ≤ 150 mA ±3 % ILED−DEV LED Channel Matching (ILED − ILEDAVG) / ILEDAVG ±3 % ROUT Output Resistance (open loop) 1x mode, IOUT = 100 mA 1.5x mode, IOUT = 100 mA 0.4 2.6 W FOSC Charge Pump Frequency 0.8 ISC_MAX Output short circuit Current Limit IIN_MAX Input Current Limit IEN/DIM VHI VLO EN/DIM Pin − Input Leakage − Logic High Level − Logic Low Level 1 1.3 MHz VOUT < 0.5 V 60 mA 1x mode, VOUT > 1 V 350 mA −1 1.3 1 0.4 mA V V TSD Thermal Shutdown 165 °C THYS Thermal Hysteresis 20 °C VUVLO Undervoltage lock out (UVLO) Threshold 2 V Table 4. RECOMMENDED EN/DIM TIMING (For 3 V ≤ VIN ≤ 5.5 V, over full ambient temperature range −40°C to +85°C.) Symbol TSETP Parameter Conditions Min EN/DIM setup from shutdown 10 TLO EN/DIM program low time 0.3 THI EN/DIM program high time 0.3 EN/DIM low time to shutdown 1.5 TOFF TD TDEC Typ Max Unit ms 200 ms ms ms LED current enable 40 ms LED current decrement 0.1 ms TSETP THI TOFF EN/DIM TLO TD TDEC 150 mA 150mA 145 mA 140 mA LED Current Shutdown 5 mA 0 mA Figure 2. LED Dimming Timing Diagram http://onsemi.com 3 Shutdown CAT3612 TYPICAL CHARACTERISTICS (VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.) 100 100 VIN = 4.2 V (1x Mode) 90 EFFICIENCY (%) 90 EFFICIENCY (%) VF = 3 V VF = 3.4 V 80 70 60 IOUT = 250 mA 80 70 60 VIN = 3.2 V (1.5x Mode) 50 50 IOUT = 100 mA 40 4.2 4.0 3.8 3.6 3.4 3.2 40 3.0 250 Figure 4. Efficiency vs. LED Current 300 0.8 QUIESCENT CURRENT (mA) QUIESCENT CURRENT (mA) 200 Figure 3. Efficiency vs. Input Voltage 0.4 0.2 LED Off 3.0 3.2 3.4 3.6 3.8 4.0 0.6 0.4 0.2 LED Off 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) 150 LED CURRENT (mA) 0.6 5 4 3 2 1 0 100 INPUT VOLTAGE (V) 0.8 0 50 3.2 3.4 3.6 4 3 2 1 LED Off LED Off 3.0 5 3.8 4.0 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 CAT3612 TYPICAL CHARACTERISTICS 5 4 4 LED CURRENT CHANGE (%) 5 3 2 1x Mode 1 0 −1 −2 1.5x Mode −3 −4 −5 3.0 3.2 3.4 3.6 3.8 4.0 1 0 −1 −2 −3 −4 80 120 Figure 9. LED Current Change vs. Input Voltage Figure 10. LED Current Change vs. Temperature 1.2 1.2 1.1 1.0 0.9 0.8 3.2 3.4 3.6 3.8 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 1.0 OUTPUT RESISTANCE (W) 4.0 0.8 0.6 0.4 0.2 0 40 TEMPERATURE (°C) 1.3 3.0 0 INPUT VOLTAGE (V) 1.3 0.7 OUTPUT RESISTANCE (W) 3 2 −5 −40 4.2 CLOCK FREQUENCY (MHz) CLOCK FREQUENCY (MHz) LED CURRENT CHANGE (%) (VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 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 CAT3612 TYPICAL CHARACTERISTICS (VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.) Figure 15. Power Up with 1 LED at 100 mA (1x Mode) Figure 16. Power Up with 1 LED at 100 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 CAT3612 TYPICAL CHARACTERISTICS (VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 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 MINIMUM TIME (nS) MINIMUM TIME (nS) 160 VIN = 3.5 V 120 80 VIN = 4.2 V 40 0 −40 0 40 80 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 40 1.2 0.8 0.6 0.4 0.2 0 −40 120 3.0 1x Mode LED Off 2.5 2.0 1.5 1.0 0.5 0 40 80 0 120 0 100 200 300 400 TEMPERATURE (°C) OUTPUT CURRENT (mA) Figure 25. Enable Voltage Threshold vs. Temperature Figure 26. Foldback Current Limit http://onsemi.com 7 500 CAT3612 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 GND Ground reference 6 LED1 LED1 cathode terminal (if not used, connect to VOUT) (Note 3) 7 LED2 LED2 cathode terminal (if not used, connect to VOUT) (Note 3) 8 C2+ 9 − 10 EN/DIM 11 − 12 VOUT TAB TAB Bucket capacitor 2 terminal Not connected Device enable (active high) and dimming control input. Not connected Charge pump output connected to the LED anodes. Connect to GND on the PCB. 3. LED1, LED2 pins should not be left floating. They should be connected to the LED cathode, or tied to the VOUT pin if not used. Pin Function VIN is the supply pin for the device. A small 1 mF ceramic bypass capacitor is required between the VIN pin and ground near the device. The operating input voltage range is up to 5.5 V. When the input supply falls below the undervoltage threshold (2 V), all LEDs channels are 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 the LED currents remain at 0 mA. The falling edge of the first pulse on EN/DIM sets the LED currents to the full scale 150 mA. On each consecutive falling edge of the pulse on EN/DIM, the LED current decreases by 150/31 mA. On the 32nd pulse, the LED current is set to zero. The next pulse on EN/DIM resets the current back to full scale 150 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, LED2 provide the internal regulated current for each of the LED cathodes. These pins enter a high impedance zero current state whenever the device is in shutdown mode. In applications using only one LED channel, the unused channel should be tied directly to VOUT. The disabled channel only draws about 0.5 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 CAT3612 Block Diagram C1− VIN C1+ C2− C2+ VOUT 1x mode (LDO) 1.5x Charge Pump Mode Control 1 MHz Oscillator EN/DIM LED1 Reference Voltage LED2 Current Setting DAC LED Channel Current Regulators Serial Interface Registers GND Figure 27. CAT3612 Functional Block Diagram Basic Operation At power−up, the CAT3612 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 LEDs 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 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 CAT3612 LED Current Setting Table 6. SELECTION OF LED CURRENT PER CHANNEL Figure 2 shows the EN/DIM input timing diagram 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 150 mA to zero with nearly 5 mA resolution. The selection of the LED current per channel is shown in Table 6. 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 CAT3612 enters the shutdown mode and draws “zero” current. For applications with 2 LEDs, each LED connected to one LED pin, refer to Figure 28. 1 mF VIN 3 V to 5.5 V CIN 2.2 mF LED Current (mA) 1 150 2 145 1 mF C1+ C1− C2+ C2− VOUT VIN CAT3612 COUT 2.2 mF LED1 ENABLE/ DIMMING Number of Pulses on EN/DIM EN/DIM Flash LED 150 mA LED2 GND Figure 28. Application with 2 LEDs http://onsemi.com 10 3 140 4 135.5 5 131 6 126 7 121 8 116 9 111 10 106.5 11 101.5 12 97 13 92 14 87 15 82 16 77.5 17 72.5 18 68 19 63 20 58 21 53 22 48.5 23 43.5 24 39 25 34 26 29 27 24 28 19 29 14.5 30 10 31 5 32 0 CAT3612 Protection Mode Recommended Layout 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 temperature drops down by about 20°C, the device resumes normal operation. 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 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. 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. Figure 29. Recommended Layout http://onsemi.com 11 CAT3612 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 E2 2.25 TYP Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MO-229. D2 http://onsemi.com 12 CAT3612 Example of Ordering Information (Note 6) 4. 5. 6. 7. 8. Prefix Device # Suffix CAT 3612 HV2 −G T2 Company ID (Optional) Product Number 3612 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 CAT3612HV2−GT2 (TDFN, NiPdAu Plated Finish, Tape & Reel, 2,000/Reel). For Matte−Tin package option, 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 13 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative CAT3612/D