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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.
Features
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TDFN-12 HV2 SUFFIX CASE 511AN
PIN CONNECTIONS
VIN C1+ C1- C2- C2+ GND (Top View) 1 VOUT EN/DIM LED4 LED3 LED2 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 LCD Display Backlight Cellular Phones Digital Still Cameras Handheld Devices
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)
Applications
* * * *
ORDERING INFORMATION
Device CAT3614HV2-T2 (Note 1) CAT3614HV2-GT2 (Note 2) Package TDFN-12 (Pb-Free) TDFN-12 (Pb-Free) Shipping 2,000/ Tape & Reel 2,000/ Tape & Reel
1. Matte-Tin Plated Finish (RoHS-compliant). 2. NiPdAu Plated Finish (RoHS-compliant).
(c) Semiconductor Components Industries, LLC, 2010
April, 2010 - Rev. 2
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Publication Order Number: CAT3614/D
CAT3614
1 mF VIN 3 V to 5.5 V CIN 1 mF 1 mF VOUT COUT 1 mF 20 mA
C1+ C1- C2+ C2- VIN VOUT CAT3614 LED1 LED2 LED3 LED4
ENABLE/ DIMMING
EN/DIM GND
Figure 1. Typical Application Circuit
NOTE: Unused LED channels must be connected to VOUT.
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter VIN, LEDx voltage VOUT, C1, C2 voltage EN/DIM voltage Storage Temperature Range Junction Temperature Range Lead Temperature Rating 6 7 VIN + 0.7 V -65 to +160 -40 to +150 300 Unit V V V C C C
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 VIN Ambient Temperature Range ILED per LED pin Total Output Current NOTE: Typical application circuit with external components is shown above. Range 3 to 5.5 -40 to +85 0 to 31 0 to 124 Unit V C mA mA
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CAT3614
Table 3. ELECTRICAL OPERATING CHARACTERISTICS
VIN = 3.6 V, EN = High, ambient temperature of 25C (over recommended operating conditions unless specified otherwise). Symbol IQ IQSHDN ILED-ACC ILED-DEV ROUT FOSC ISC_MAX IIN_MAX IEN/DIM VHI VLO TSD THYS VUVLO Parameter Quiescent Current Shutdown Current LED Current Accuracy LED Channel Matching Output Resistance (open loop) Charge Pump Frequency Output short circuit Current Limit Input Current Limit EN/DIM Pin - Input Leakage - Logic High Level - Logic Low Level Thermal Shutdown Thermal Hysteresis Undervoltage lock out (UVLO) threshold VOUT < 0.5 V 1x mode, VOUT > 1 V Conditions 1x mode, no load 1.5x mode, no load VEN = 0 V 1 mA ILED 31 mA (ILED - ILEDAVG) / ILEDAVG 1x mode, IOUT = 100 mA 1.5x mode, IOUT = 100 mA 0.8 30 200 -1 1.3 145 10 1.7 165 20 2 3 3 0.4 2.6 1 60 300 Min 0.3 1 Typ 0.5 3 Max 1 8 1 8 7 1 7 1.3 100 600 1 0.4 175 30 2.4 Unit mA mA % % W MHz mA mA mA V V C C V
Table 4. RECOMMENDED EN/DIM TIMING (For 3 V VIN 5.5 V, over full ambient temperature range -40 to +85C.)
Symbol TSETP TLO THI TOFF TD TDEC Parameter EN/DIM setup from shutdown EN/DIM program low time EN/DIM program high time EN/DIM low time to shutdown LED current enable LED current decrement TSETP EN/DIM TD TLO TDEC 31 mA 30 mA 29 mA LED Current Shutdown 1 mA 0 mA Shutdown 31 mA THI Conditions Min 10 0.3 0.3 1.5 40 0.1 TOFF 200 Typ Max Unit ms ms ms ms ms ms
Figure 2. LED Dimming Timing Diagram
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CAT3614
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25C unless otherwise specified.) 100 20 mA per LED 90 1x mode EFFICIENCY (%) EFFICIENCY (%) 80 70 10 mA per LED 60 50 40 4.2 4.0 3.8 3.6 90 80 70 60 50 3.2 3.0 40 0 VIN = 3.2 V (1.5x Mode) VIN = 4 V (1x Mode) 100
1.5x mode 3.4
25
50
75
100
125
INPUT VOLTAGE (V)
TOTAL LED CURRENT (mA)
Figure 3. Efficiency vs. Input Voltage (4 LEDs)
0.8 QUIESCENT CURRENT (mA) QUIESCENT CURRENT (mA) 0.8
Figure 4. Efficiency vs. Total LED Current (4 LEDs)
0.6
0.6
0.4 4 LEDs OFF 0.2
0.4 4 LEDs OFF 0.2
0
3.0
3.2
3.4
3.6
3.8
4.0
4.2
0 -40
0
40 TEMPERATURE (C)
80
120
INPUT VOLTAGE (V)
Figure 5. Quiescent Current vs. Input Voltage (1x Mode)
6 QUIESCENT CURRENT (mA) 5 4 3 2 4 LEDs OFF 1 0 QUIESCENT CURRENT (mA) 6 5 4 3 2
Figure 6. Quiescent Current vs. Temperature (1x Mode)
4 LEDs OFF 1 0 -40
3.0
3.2
3.4
3.6
3.8
4.0
4.2
0
40 TEMPERATURE (C)
80
120
INPUT VOLTAGE (V)
Figure 7. Quiescent Current vs. Input Voltage (1.5x Mode)
Figure 8. Quiescent Current vs. Temperature (1.5x Mode)
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CAT3614
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25C unless otherwise specified.) 5 LED CURRENT CHANGE (%) 3 2 1 0 -1 -2 -3 -4 -5 3.0 3.2 3.4 3.6 3.8 4.0 4.2 1.5x Mode 1x Mode LED CURRENT CHANGE (%) 4 5 4 3 2 1 0 -1 -2 -3 -4 -5 -40 -20 0 20 40 60 80
INPUT VOLTAGE (V)
TEMPERATURE (C)
Figure 9. LED Current Change vs. Input Voltage
1.3 CLOCK FREQUENCY (MHz) CLOCK FREQUENCY (MHz) 1.2 1.1 1.0 4 LEDs at 20 mA 0.9 0.8 0.7 1.3 1.2 1.1 1.0 0.9 0.8 0.7 -40
Figure 10. LED Current Change vs. Temperature
3.0
3.2
3.4
3.6
3.8
4.0
0
40 TEMPERATURE (C)
80
120
INPUT VOLTAGE (V)
Figure 11. Oscillator Frequency vs. Input Voltage
1.0 OUTPUT RESISTANCE (W) 0.8 0.6 OUTPUT RESISTANCE (W) 4.0 3.5 3.0 2.5 2.0 1.5 1.0
Figure 12. Oscillator Frequency vs. Temperature
0.4 0.2 0
3.0
3.2
3.4
3.6
3.8
4.0
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)
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CAT3614
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25C 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
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CAT3614
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 80 mA (4 LEDs at 20 mA), C1 = C2 = CIN = COUT = 1 mF, TAMB = 25C unless otherwise specified.)
Figure 21. Enable and Output Current Dimming Waveforms
200 160 MINIMUM TIME (nS) MINIMUM TIME (nS) VIN = 3.5 V 120 80 VIN = 4.2 V 40 0 -40 200
Figure 22. Line Transient Response (3.6 V to 5.5 V) 1x Mode
VIN = 3.5 V 160 120 VIN = 4.2 V 80 40 0 -40
0
40 TEMPERATURE (C)
80
120
0
40 TEMPERATURE (C)
80
120
Figure 23. Enable High Minimum Program Time vs. Temperature
1.2 1.0 OUTPUT VOLTAGE (V) ENABLE VOLTAGE (V) 0.8 0.6 0.4 0.2 0 -40 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 40 TEMPERATURE (C) 80 120 0 0
Figure 24. Enable Low Minimum Program Time vs. Temperature
1x Mode VIN = 3.5 V
100
200
300
400
OUTPUT CURRENT (mA)
Figure 25. Enable Voltage Threshold vs. Temperature
Figure 26. Foldback Current Limit
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CAT3614
Table 5. PIN DESCRIPTIONS
Pin # 1 2 3 4 5 6 7 8 9 10 11 12 TAB Name VIN C1+ C1- C2- C2+ GND LED1 LED2 LED3 LED4 EN/DIM VOUT TAB Supply voltage. Bucket capacitor 1 terminal Bucket capacitor 1 terminal Bucket capacitor 2 terminal Bucket capacitor 2 terminal Ground reference LED1 cathode terminal (if not used, connect to VOUT) (Note 3) LED2 cathode terminal (if not used, connect to VOUT) (Note 3) LED3 cathode terminal (if not used, connect to VOUT) (Note 3) LED4 cathode terminal (if not used, connect to VOUT) (Note 3) Device enable (active high) and dimming control input Charge pump output connected to the LED anodes Connect to GND on the PCB Function
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.
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CAT3614
Block Diagram
1 mF C1- C1+ 1 mF C2- C2+
VIN CIN 1 mF
1x mode (LDO) 1.5x Charge Pump
VOUT
EN/DIM
1 MHz Oscillator
Mode Control LED1 LED2
Reference Voltage Current Setting DAC
LED3 LED4
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).
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CAT3614
LED Current Setting
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.
Protection Mode
temperature drops down by about 20C, the device resumes normal operation.
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
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 +165C. When the device
1 mF C1+ VIN CAT3614 LED1 LED2 EN/DIM GND LED3 LED4 C1- C2+ 1 mF C2- VOUT COUT 1 mF
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.
1 mF
1 mF
VIN 3 V to 5.5 V CIN 1 mF ENABLE/ DIMMING
VIN 3 V to 5.5 V CIN 1 mF ENABLE/ DIMMING
C1+ VIN
C1- C2+
C2- VOUT COUT 1 mF LED1 LED2
Flash LED
CAT3614
EN/DIM GND
LED3 LED4
120 mA
Figure 28. Three LED Application
Figure 29. Single Flash LED Application
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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
D2 BOTTOM VIEW
TOP VIEW
SYMBOL A A1 A3 b D D2 E E2 e L M N P R
MIN 0.70 0.00 0.178 0.18 2.90 2.30 2.90 1.55 0.30 0.25 0.60 2.70
NOM 0.75 0.02 0.203 0.23 3.00 2.40 3.00 1.70 0.45 BSC 0.40 0.30 0.70 3.00 2.25 TYP
MAX 0.80 0.05 0.228 0.30 3.10 2.50 3.10 1.75 0.50 0.35 0.80 3.10 P E2 e RECOMMENDED LAND PATTERN R M N A1 FRONT VIEW A A3
Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MO-229.
D2
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CAT3614
Example of Ordering Information (Note 6)
Prefix CAT Device # 3614 Suffix 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
4. 5. 6. 7. 8.
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. 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: orderlit@onsemi.com 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 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative
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CAT3614/D

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