LT3590 LINER
Document overview
- Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 16
Technical content
FEATURES
APPLICATIONS
DESCRIPTION
The L T®3590 is a fi xed frequency buck mode converter specifi cally designed to drive up to 10 LEDs in series from a 48V DC source. Series connection of the LEDs provides identical LED currents of up to 50mA, resulting in uniform brightness and eliminating the need for ballast resistors. A fi xed frequency, current mode architecture results in stable operation over a wide range of input voltage and output voltage. The high switching frequency of 850kHz permits the use of tiny, low profi le inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. The power switch, Schottky diode and control circuitry are all contained inside a space saving SC70 package or 2mm × 2mm DFN package to allow a small converter footprint and lower parts cost. Buck Mode Driver for Ten White LEDs ■ 4.5V to 55V Input Voltage Range ■ Up to 50mA LED Current ■ 80mA, 55V Switch ■ Internal Schottky Diode ■ 15μA Supply Current in Shutdown ■ 500μA Supply Current Operating, Not Switching ■ Switching Frequency: 850kHz ■ 200mV Feedback Voltage with ±5% Accuracy ■ CTRL Input Performs Dimming and Shutdown ■ 91% Effi ciency (10 LEDs, 50mA) ■ Requires Only 1μF Output Capacitor ■ 8-Lead SC70 Package ■ 6-Lead 2mm × 2mm DFN Package ■ LED Fixed Signage ■ T raffi c Signs ■ Neon Sign Replacement , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. VIN 48V CONTROL CTRL VIN 50mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF
3590 TA01a
470μH Conversion Effi ciency LED CURRENT (mA) EFFICIENCY (%) 30 50 10 20 40 100
3590 TA01b
Operating Junction Temperature Range (Note 1) Lead Temperature (Soldering, 10 sec) LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE L T3590EDC#PBF L T3590EDC#TRPBF LCNZ 6-Lead (2mm × 2mm) Plastic DFN –40°C to 85°C L T3590ESC8#PBF L T3590ESC8#TRPBF LCPB 8-Lead Plastic SC70 –40°C to 85°C Consult L TC Marketing for parts specifi ed with wider operating temperature ranges. Consult L TC Marketing for information on non-standard lead based fi nish parts. For more information on lead free part marking, go to: http://www.linear .com/leadfree/ For more information on tape and reel specifi cations, go to: http://www.linear .com/tapeandreel/ TOP VIEW VREG LED V IN CTRL GND SW DC PACKAGE 6-LEAD (2mm × 2mm) PLASTIC DFN
1 SW 1
7 LED
6 VREG
5 CTRL
TJMAX = 125°C, θJA = 75°C/W TO 95°C/WTJMAX = 125°C, θJA = 65°C/W TO 85°C/W , θJC = 20°C/W EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB PIN CONFIGURATION ORDER INFORMATION
ELECTRICAL CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The L T3590E is guaranteed to meet performance specifi cations from 0°C to 85°C junction temperature. Specifi cations over the –40°C to 85°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Operating Voltage 4.5 V LED Current Sense Voltage (VIN -V LED) ● 190 200 210 mV Sense Voltage Load Regulation ΔI LED = 10mA to 50mA 5 m V Quiescent Current ON, No Switching V LED = 47.7V 500 700 μA Quiescent Current in Shutdown V CTRL = 0V 15 20 μA Switching Frequency ● 650 850 1050 kHz Maximum Duty Cycle ● 90 % Switch Current Limit 80 115 150 mA Switch VCESAT ISW = 50mA 500 mV Switch Leakage Current V SW = 48V 1 2 μA VCTRL for Full LED Current ● 1.5 V VCTRL to Shut Down IC 100 mV VCTRL to Turn on IC 150 mV CTRL Pin Bias Current V CTRL = 1V , Current Out of Pin 100 nA LED Pin Bias Current V LED = 47.8V 9 14 μA LDO Voltage VREG IVREG = 1mA 3.1 3.3 3.5 V LDO Load Regulation ΔI VREG = 0mA to 1mA 17 mV LDO Current Limit 1.5 mA Schottky Forward Drop I SCHOTTKY = 50mA 0.8 V Schottky Leakage Current V R = 48V 4 μA The ● denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C, VIN = 48V , VCTRL = 3.3V , unless otherwise noted.
SWITCH CURRENT (mA) SWITCH SATURATION VOLTAGE (V) 0.6 0.7 100 0.5 0.4 0.2 40 60 80 0.3 0.8
3590 G01
–40°C 25°C 125°C SCHOTTKY FORWARD CURRENT (mA) SCHOTTKY FORWARD DROP (V) 0.8 0.9 1.0 200 0.7 0.6 0.4 50 100 150 0.5 1.2 1.1
3590 G02
–40°C 25°C 125°C VIN (V) SHUTDOWN CURRENT (μA)12 10 20 30 40
3590 G03
VCTRL = 0V TA = 25°C TEMPERATURE (°C) –50 SHUTDOWN CURRENT (μA) –25 0 50 75 100 125
3590 G04
VCTRL = 0V VIN = 48V
400 QUIESCENT CURRENT (μA)450
3590 G05
VIN (V) VCTRL = 3.3V TA = 25°C TEMPERATURE (°C) –50 SCHOTTKY LEAKAGE CURRENT (μA) 1.0 –25 0 50 0.5 2.0 1.5 75 100 125
3590 G06
VIN = 48V VIN = 24V VIN = 4.5V 1μs/DIV VSW 20V/DIV IL 20mA/DIV
3590 G07
VIN = 48V ILED = 50mA
10 WHITE LEDs
L = 470μH (COILCRAFT) 40μs/DIV CTRL 5V/DIV I LED 50mA/DIV VSW 50V/DIV IL 50mA/DIV
3590 G08
VIN = 48V ILED = 50mA
10 BLUE LEDs
TYPICAL PERFORMANCE CHARACTERISTICS Switch Saturation Voltage (VCESAT) Schottky Forward Voltage Drop Shutdown Quiescent Current vs VIN Shutdown Quiescent Current vs Temperature Quiescent Current Schottky Leakage Current Switching Waveform T ransient Response
TYPICAL PERFORMANCE CHARACTERISTICS Sense Voltage (VIN – VLED) vs VCTRL Switching Current Limit vs Duty Cycle Switching Current Limit vs Temperature Sense Voltage (V IN – VLED) vs VIN Sense Voltage (VIN – VLED) vs Temperature Switching Frequency over Temperature Internal Regulator Line Regulation Internal Regulator Load Regulation Internal Regulator VREG vs Temperature VCTRL (V) SENSE VOLTAGE (VIN-VLED) 0.20 0.15 0.10 0.5 1 1.5 0.05 0.25
3590 G09
VIN = 48V ILED = 50mA TA = 25°C DUTY CYCLE (%) 120 130 140 110 100 20 40 60 100 150 SWITCHING CURRENT LIMIT (mA)
3590 G10
TA = 25°C TEMPERATURE (°C) –50 SWITCHING CURRENT LIMIT (mA) 110 –25 0 50 150 140 130 120 100 75 100 125
3590 G11
VIN (V) 206 204 202 200 198 196 194 30 5010 20 40 60 VIN-VLED (mV)
3590 G12
ILED = 50mA T A = 25°C TEMPERATURE (°C) –50 VIN-VLED (mV) 206 200 196 –25 0 50 194 204 202 198 75 100 125
3590 G13
TEMPERATURE (°C) –50 SWITCHING FREQUENCY (KHz) 900 800 –25 0 50 750 700 1000 950 850 75 100 125
3590 G14
VIN = 48V VIN (V) 3.40 3.35 3.30 3.25 3.20 3010 20 40 60 50 VREG (V)
3590 G15
VCTRL = 3.3V ILOAD = 1mA VCTRL = 0V ILOAD = 0V TA = 25°C ILOAD (mA) 3.40 3.35 3.30 3.25 3.20 0.60.2 0.4 0.8 1 VREG (V)
3590 G16
VCTRL = 0V ILED = 0V VCTRL = 3.3V ILED = 50mA TA = 25°C TEMPERATURE (°C) –50
3.20 TREG (V)
3.25 3.30 3.35 3.40 –25 0 25 50
3590 G17
VCTRL = 3.3V ILOAD = 1mA
pin to minimize EMI. Connect the inductor at this pin. achieve the rated thermal performance. CTRL (Pin 5/Pin 1): Dimming and Shutdown Pin. highest LED and the sense resistor . Figure 1. Block Diagram
is fed into the positive terminal of the PWM comparator . pin is used to adjust the reference voltage. the input supply, the device will begin skipping pulses. though this will degrade effi ciency. Figure 2. Switching Waveforms
3590 F02
comparison of different inductors is shown in Figure 3. Table 1. Inductor Manufacturers
100 TO 680
100 TO 330
100 TO 390
100 TO 270
100 TO 220
Figure 3. Effi ciency Comparison of Different Inductors one or two LEDs a 2.2μF output capacitor is needed. on their entire selection of ceramic parts.
3590 F03
10 LEDs
age (VIN -V LED) control the LED current. Table 3. R1 Theoretical Value for 200mV Sense There are three different types of dimming control circuits. control is a variable DC voltage to adjust the LED current. it has no effect on the LED current. (Figure 5) by a RC network and fed to the CTRL pin. Figure 4. Dimming and Shutdown Using CTRL Pin
3590 F04
Figure 5. Dimming Control Using a Filtered PWM Signal
3590 F05
changes the intensity of the LEDs, it also changes the color . dimming offers a wider dimming range to the user . typical human eye has a limit of ~60 frames per second.
- . •Duty Cycle t t μs s SETTLE PERIOD == 100 50 00 1 1000 0 5 100 0 5 100 %. %Duty Cycle Range at Hz The calculations show that for a 100Hz signal the dimming range is 200 to 1. In addition, the minimum PWM duty cycle of 0.5% ensures that the LED current has enough time to settle to its fi nal value. Figure 7 shows the dim- ming range achievable for three different frequencies with a settling time of 50μs. APPLICATIONS INFORMATION
Figure 7. Dimming Range Comparison Figure 6. Direct PWM Dimming Waveforms
4 LEDs
3590 F06
3590 F07
3590 F08
Figure 8. Recommended Component Placement dimmed fi rst, modulating the duty cycle of the PWM signal. PWM signal can be decreased below 1.5V down to 150mV . 50mA down to less than 50μA. to ground. The regulator current is limited to 1.5mA. paid to the PCB board layout and component placement.
48V Supply for 5 LED String, 30mA Current Conversion Effi ciency TYPICAL APPLICATIONS 24V Supply for a 5 LED String, 30mA Current VIN 48V CONTROL >1.5V L1: MURATA LQH32CN-391 CTRL VIN 6.8Ω 30mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF 3590 TA03a 470μH VIN 24V CONTROL >1.5V L1: MURATA LQH32CN-221 CTRL VIN 6.8Ω 30mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF 3590 TA04a 220μH 48V Supply for 6 LED String, 50mA Current Conversion Effi ciency VIN 48V CONTROL >1.5V L1: MURATA LQH32CN221K03 CTRL VIN LEDs 50mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF 3590 TA02a 470μH Conversion Effi ciency LED CURRENT (mA) EFFICIENCY (%) 30 50 10 20 40 100
3590 TA02b
LED CURRENT (mA) 100 15 2551 0 20 30 EFFICIENCY (%)
3590 TA03b
LED CURRENT (mA) 100 15 2551 0 20 30 EFFICIENCY (%)
3590 TA04b
LED CURRENT (mA) EFFICIENCY (%)55 30 50 10 20 40
3590 TA05b
Conversion Effi ciency TYPICAL APPLICATIONS VIN 12V OR 24V CONTROL >1.5V CTRL VIN 50mA L T3590 VREG SW LED GND 2.2μF 0.1μF 1μF 3590 TA05a 220μH 12V or 24V Supply for a Single LED, 50mA Current Conversion Effi ciency48V Supply for T wo Strings of 10 LEDs, 25mA Current VIN 48V CONTROL >1.5V CTRL VIN 25mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF
3590 TA06a
470μH 25mA Conversion Effi ciency12V Supply for a 3 LED String, 50mA Current VIN 12V CONTROL >1.5V L1: MURATA LQH32CN-221 CTRL VIN 50mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF 3590 TA07a 220μH LED CURRENT (mA) EFFECIENCY (%) 100 51 0 1 5 2 0
3590 TA06b
LED CURRENT (mA) EFFICIENCY (%) 30 50 10 20 40 100
3590 TA07b
6-Lead Plastic DFN (2mm × 2mm) (Reference L TC DWG # 05-08-1703) 2.00 ±0.10 (4 SIDES) NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WCCD-2) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 0.38 ± 0.05 BOTTOM VIEW—EXPOSED PAD 0.56 ± 0.05 (2 SIDES) 0.75 ±0.05 R = 0.115 TYP 1.37 ±0.05 (2 SIDES) PIN 1 BAR TOP MARK (SEE NOTE 6)
0.200 REF
0.00 – 0.05 (DC6) DFN 1103 0.25 ± 0.05 1.42 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 0.61 ±0.05 (2 SIDES)1.15 ±0.05 0.675 ±0.05 2.50 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC0.50 BSC PIN 1 CHAMFER OF EXPOSED PAD
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However , no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. PACKAGE DESCRIPTION 8-Lead Plastic SC70 (Reference L TC DWG # 05-08-1639 Rev Ø) 1.15 – 1.35 0.15 – 0.27
8 PLCS (NOTE 3)
SC8 SC70 0905 REV Ø 1.80 – 2.20 (NOTE 4)
0.50 BSC
0.80 – 1.00
1.00 MAX
0.00 – 0.10 REF NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. DETAILS OF THE PIN 1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE INDEX AREA 7. EIAJ PACKAGE REFERENCE IS EIAJ SC-70 AND JEDEC MO-203 VARIATION BA
2.8 BSC
0.30 MAX 0.50 REF RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR
1.8 REF
1.00 REF
(NOTE 6) 0.10 – 0.18 (NOTE 3) 0.26 – 0.46 GAUGE PLANE
0.15 BSC
0.10 – 0.40
Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear .com © LINEAR TECHNOLOGY CORPORATION 2007 LT 0707 • PRINTED IN USA RELATED PARTS PART NUMBER DESCRIPTION COMMENTS L T1932 Constant Current, 1.2MHz, High Effi ciency White LED Boost Regulator VIN: 1.0V to 10.0V , VOUT(MAX) = 34V , Dimming Analog/PWM, ISD < 1μA, ThinSOT™ Package L T3003 Three Channel LED Ballaster with PWM Dimming V IN: 3.0V to 48.0V , Dimming 3,000:1 T rue Color PWM™, ISD <5μA, MSOP-10 Package L T3465/A Constant Current, 1.2/2.7MHz, High Effi ciency White LED Boost Regulator with Integrated Schottky Diode V IN: 2.7V to 16.0V , VOUT(MAX) = 34V , Dimming Analog/PWM, ISD <1μA, ThinSOT Package L T3466/-1 Dual Constant Current, 2MHz, High Effi ciency White LED Boost Regulator with Integrated Schottky Diode V IN: 2.7V to 24.0V , VOUT(MAX) = 40V , Dimming 5mA, ISD <16μA, 3mm × 3mm DFN-10 L T3474 36V , 1A (ILED), 2MHz,Step-Down LED Driver V IN: 4.0V to 36V , VOUT(MAX) = 13.5V , Dimming 400:1 T rue Color PWM, ISD <1μA, TSSOP16E Package L T3475 Dual 1.5A(ILED), 36V , 2MHz, Step-Down LED Driver V IN: 4.0V to 36V , VOUT(MAX) = 13.5V , Dimming 3,000:1 T rue Color PWM, ISD <1μA, TSSOP20E Package L T3476 Quad Output 1.5A, 2MHz High Current LED Driver with 1,000:1 Dimming V IN: 2.8V to 16.0V , VOUT(MAX) = 36.0V , Dimming 1,000:1 T rue Color PWM, ISD <10μA, 5mm × 7mm QFN-10 L T3478/-1 4.5A, 2MHz High Current LED Driver with 3,000:1 Dimming V IN: 2.8V to 36.0V , VOUT(MAX) = 40.0V , Dimming 1,000:1 T rue Color PWM, ISD <10μA, 5mm × 7mm QFN-10 L T3486 Dual 1.3A, 2MHz High Current LED Driver V IN: 2.5V to 24.0V , VOUT(MAX) = 36.0V , Dimming 1,000:1 T rue Color PWM, ISD <1μA, 5mm × 3mm DFN, TSSOP-16E Package L T3491 Constant Current, 2.3MHz, High Effi ciency White LED Boost Regulator with Integrated Schottky Diode V IN: 2.5V to 12.0V , VOUT(MAX) = 27V , Dimming 300:1 T rue Color PWM, ISD <8μA, 2mm × 2mm DFN-6, SC70 Package L T3496 T riple Output 750mA, 2.1 MHz High Current LED Driver with 3,000:1 Dimming V IN: 3.0V to 30.0V , VOUT(MAX) = 40.0, Dimming 3,000:1 T rue Color PWM, ISD <1μA, 4mm × 5mm QFN-28 L T3497 Dual 2.3MHz, Full Function LED Driver with Integrated Schottkys and 250:1 T rue Color PWM Dimming V IN: 2.5V to 10.0V , VOUT(MAX) = 32, Dimming 250:1 T rue Color PWM, ISD <12μA, 2mm × 3mm DFN-10 L T3498 20mA LED Driver and OLED Driver Integrated Schottkys V IN: 2.5 to 12.0V , VOUT(MAX) = 32, Dimming Analog/PWM, ISD <8.5μA, 2mm × 3mm DFN-12 L T3517 1.3A, 2.5MHz High Current LED Driver with 3,000:1 Dimming V IN: 3.0V to 30.0V , Dimming 3,000:1 T rue Color PWM, ISD <1μA, 4mm × 4mm QFN-16 L T3518 2.3A, 2.5MHz High Current LED Driver with 3,000:1 Dimming V IN: 3.0V to 30.0V , Dimming 3,000:1 T rue Color PWM, ISD <1μA, 4mm × 4mm QFN-16 L T3591 Constant Current, 1MHz, High Effi ciency White LED Boost Regulator with Integrated Schottky Diode and 80:1 T rue Color PWM Dimming V IN: 2.5V to 12.0V , VOUT(MAX) = 40, Dimming 80:1 T rue Color PWM, ISD <9μA, 2mm × 3mm DFN-8 ThinSOT and T rue Color PWM are trademarks of Linear Technology Corporation. TYPICAL APPLICATION 24V Supply for 6 LED String, 50mA Current Conversion Effi ciency VIN 24V CONTROL >1.5V L1: MURATA LQH32CN-221 CTRL VIN 50mA L T3590 VREG SW LED GND 1μF 0.1μF 1μF
3590 TA08a
220μH LED CURRENT (mA) EFFICIENCY (%)75 30 50 10 20 40 100