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FEATURES

LT3003 3-Channel LED Ballaster with PWM DESCRIPTIO
The LT(R)3003 drives three separate strings of LEDs up to 350mA/channel with 3% accurate current matching, resulting in uniform LED brightness and intensity. This approach is superior to conventional methods of running three separate channels with external ballast resistors requiring expensive factory calibration. The LT3003 operates in boost mode, "buck mode" and "buck-boost mode". A True Color PWM Dimming ratio of up to 3000:1 is achievable using a logic-level signal at the PWM pin for all modes without the need for external level-shifting circuitry. For applications with input supply above and below the output voltage of the LED strings, the LT3003 allows the LEDs to be returned to the input supply ("buck-boost mode") instead of being limited to only SEPIC solutions. The LT3003 is ideal for high power LED driver applications such as TFT LCD backlighting and heads-up displays. Additional overtemperature outputs allow appropriate system management for increased reliability. The LT3003 is available in a small 10-pin MSE package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. True Color PWM is a trademark of Linear Technolology Corporation. All other trademarks are the property of their respective owners.
3% LED Current Matching Up to 350mA Continuous Current per LED String Up to 3000:1 True Color PWMTM Dimming Range PWM Input Disconnects LED Strings Can Operate in Buck, Boost and Buck-Boost Modes Wide Input Range: 3V to 40V Overtemperature Outputs Works with LT1618, LT3477, LT3474, LT3475, LT3476, LTC(R)3783 Thermally Enhanced 10-Pin MSOP Package
APPLICATIO S

High Power LED Ballaster Automotive Lighting Video Cameras TFT LCD Backlighting
TYPICAL APPLICATIO
PVIN 33V 1F 0.1
"Buck Mode" LT3003 with the LT3476
90
24 LEDs/CHANNEL ILED = 350mA
85 80 75 70 65
LED1 VIN VMAX SHDN VEE 1F
LED2 LT3003
LED3 OT1 OT2 PWM GND
EFFICIENCY (%)
10H
0.33F
PVIN = 33V NUMBER OF LEDS = 8 * 3 = 24 60 0 200 400 600 800 TOTAL ILED (mA) 1000 1200
CAP LED VIN 3V TO 16V 10F VIN
SW
VC 1nF PWM
3003 TA01a
SIMPLIFIED LT3476 GND PWM
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Efficiency
3003 TA02b
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LT3003 ABSOLUTE
(Note 1)
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RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW LED1 LED2 LED3 VMAX VIN 1 2 3 4 5 10 9 8 7 6 VEE SHDN OT2 OT1 PWM 11
VIN ............................................................................40V LED1, LED2, LED3 ....................................................48V VMAX, SHDN ..............................................................48V VIN - VEE ...................................................................36V VEE ............................................................................36V PWM .........................................................................15V OT1, OT2.....................................................................6V Operating Junction Temperature Range (Notes 2, 3, 4) ........................................ -40C to 125C Storage Temperature Range................... -65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C
MSE PACKAGE 10-LEAD PLASTIC MSOP TJMAX = 125C, JA = 35C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER LT3003EMSE
MSE PART MARKING LTCFF
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
PARAMETER VIN Operational Input Voltage Minimum (VIN - VEE) VIN Quiescent Current VIN Shutdown Current VMAX Quiescent Current SHDN Pin Threshold LED Current Matching |LED2 - LED1|, |LED2 - LED3| LED Current Matching with LED Pin Voltage Mismatch LED Pin Voltage LED1, LED2, LED3 Maximum Current LED1, LED2, LED3 Maximum Leakage Current PWM Switching Threshold Turn-On Delay (PWM On to ILED On) VEE Pin Current in Buck Mode Overtemperature Sense Point (OT1, OT2) Overtemperature Hysteresis Point OT1 Pull-Down Current
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. PWM = 1V, VMAX = 4V, VIN = 3V, VEE = 0V, ILED2 = 100mA, OT1 = OT2 = Open, SHDN = VIN.
CONDITIONS VEE = 0V, ILED1,2,3 = 100mA VEE = 4V, ILED1,2,3 = 100mA VEE = 0V to 36V PWM = 1V, ILED1,2,3 = 100mA PWM = 0V, VLED1 = VLED2 = VLED3 SHDN = 0V, ILED1,2,3 = 0mA PWM = 1V, ILED2 = 100mA PWM = 0V, VLED1 = VLED2 = VLED3 ILED2 = 100mA, VLED1 = VLED2 = VLED3 ILED2 = 350mA, VLED1 = VLED2 = VLED3 ILED2 = 350mA, (|VLED2 - VLED1| + |VLED2 - VLED3|) = 700mV ILED2 = 100mA VLED1,2,3 < 1.5V PWM = 0V, VLED1,2,3 = 48V ILED1,2,3 = 100mA PWM = 0V to 1V, ILED > 50mA PWM = 0V, VMAX = 40V, VIN = 39V, VEE = 36V (Note 4) (Note 5) OT1 = 0.3V (Note 4)

MIN 3
TYP
MAX 36 40
UNITS V V V mA A A A nA V % % V mA A V s A C C A
2.7 10.5 470 2 4 55 20 0.25 -3 -3.5 0.7 375 0.3 0.7 0 0.5 0.8 500 0.1 0.5 2 0.1 125 -6 from Overtemp Sense Point 100
3 600 10 90 300 1 +3 +3.5 0.9 550 1 0.7 1
2
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LT3003 ELECTRICAL CHARACTERISTICS
PARAMETER OT2 Pull-Down Current OT1, OT2 Leakage Current
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. PWM = 1V, VMAX = 4V, VIN = 3V, VEE = 0V, ILED2 = 100mA, OT1 = OT2 = Open, SHDN = VIN.
CONDITIONS OT2 = 0.3V (Note 4) OT1 = OT2 = 5V MIN 300 1 TYP MAX UNITS A A
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 LT3003E is guaranteed to meet performance specifications from 0C to 85C junction temperature. Specifications over the -40C to 125C operating junction temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 4: Correlation to static test at TA = 25C. Note 5: Guaranteed by design.
TYPICAL PERFOR A CE CHARACTERISTICS
ILED1,3 to ILED2 Matching
3.0 35 INPUT QUIESCENT CURRENT (mA) 30 25 20 15 10 5 0 125 50 100 150 250 200 ILED (mA) ILED1,3 - ILED2 ILED2 2.5 I LED2 = 350mA VLED1 = VLED2 = VLED3 2.0 1.5 1.0 0.5 0 0 50 75 100 25 -50 -25 JUNCTION TEMPERATURE (C)
VEE PIN CURRENT * -1 (nA)
ILED1,3 vs ILED2 (%)
VMAX Pin Current vs Temperature
10 9 8 VMAX PIN CURRENT (nA) 7 6 5 4 3 2 1 0 50 25 0 75 100 -50 -25 JUNCTION TEMPERATURE (C) 125 10s AFTER PWM = 0 VIN SHUTDOWN CURRENT (A) 7 6 5 4 3 2 1
(VLED1,2,3 - VEE) (mV)
UW
TA = 25C unless otherwise noted. VEE Pin Current (Out of the Pin) vs Temperature
500 450 400 350 300 250 200 150 100 50 300 350
3003 G02
VIN Quiescent Current vs ILED
TJ = 27C
10s AFTER PWM = 0
0 50 25 0 75 100 -50 -25 JUNCTION TEMPERATURE (C)
125
3003 G01
3003 G03
VIN Shutdown Current vs Temperature
SHDN = 0 1150 1100 1050 1000 950 900 850 800
(VLED1,2,3 - VEE) vs ILED
0 50 100 -50 -25 25 75 0 JUNCTION TEMPERATURE (C)
125
50
100
150
200
250
300
350
400
ILED (mA)
3003 G06
3003 G04
3003 G05
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LT3003 TYPICAL PERFOR A CE CHARACTERISTICS
VIN Quiescent Current vs ILED
35 VIN QUIESCENT CURRENT (mA) VIN SHUTDOWN CURRENT (A) 30 25 20 15 10 5 0 50 100 150 250 200 ILED (mA) 300 350
3003 G07
PI FU CTIO S
LED1 (Pin 1): Controlled current input for a string of LEDs with a cathode lead connected to the pin. Connect the first string of LEDs to this pin. LED2 (Pin 2): Controlled current input for a string of LEDs with a cathode lead connected to the pin. Connect the second string of LEDs to this pin. LED3 (Pin 3): Controlled current input for a string of LEDs with a cathode lead connected to the pin. Connect the third string of LEDs to this pin. VMAX (Pin 4): * Boost Mode: Connect to VOUT * Buck Mode: Connect to Input Supply * Buck-Boost Mode: Connect to VOUT VIN (Pin 5): Input Supply, Upper Rail. This pin must be locally bypassed with a capacitor to ground. VIN powers the internal control circuitry. * Boost Mode: Connect to Input Supply * Buck Mode: Connect to Input Supply * Buck-Boost Mode: Connect to VOUT PWM (Pin 6): Input Pin for PWM Dimming Control. A PWM signal above 0.5V (on threshold) turns the LT3003 channels on. A PWM signal below 0.5V completely disconnects each LED string. If the application does not require PWM dimming, then the PWM pin can be left either open (an internal 10A source current pulls PWM high) or it can be connected to a supply between 0.5V to 15V. OT1 (Pin 7): Overtemperature Output. OT1 pulls 100A from the pin when the junction temperature exceeds 125C. The part has to cool down by 6C for the flag to reset; ideal for providing an overtemperature flag to the system microprocessor. OT2 (Pin 8): Overtemperature Output. OT2 Pulls 300A from the pin when the junction temperature exceeds 125C. The part has to cool down by 6C for the flag to reset; ideal for connecting to the switching regulator gm error amplifier output to defeat switching. SHDN (Pin 9): Micropower Shutdown Pin. Below 0.7V shuts down the IC. Typically IVIN = 4A for SHDN = 0V. * Boost Mode: Connect to System Shutdown Signal or VIN * Buck Mode: Connect to System Shutdown Signal or VIN * Buck-Boost Mode: Connect to PWM (Pin 6) * If Unused SHDN can be Connected to VIN
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TA = 25C unless otherwise noted.
VIN Shutdown Current vs VIN
16 14 12 10 8 6 4 2 0 3 8 13 23 18 VIN (V) 28 33 38
3003 G08
SHDN = 0
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LT3003 PI FU CTIO S
VEE (Pin 10): Lower Rail. * Boost Mode: Connect to System Ground * Buck Mode: Connect to Inductor * Buck-Boost Mode: Connect to Input Supply Exposed Pad (Pin 11): GND. The ground for the IC should be soldered to a continuous copper ground plane under the LT3003 die. Soldering the Exposed Pad to the copper ground plane under the device will reduce die temperature and increase the power capability of the LT3003.
BLOCK DIAGRA
1 LED1
B1
6
PWM
+
0.5V
-
BIAS BG
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4 VMAX VIN
2 LED2
3 LED3
+ -
B2
+ -
B3
VEE B1 B2 B3
10
PWM LOGIC
+ -
3V
VIN
5
VEE
+ -
THERMAL SHUTDOWN BG 125C 150C 0.7V
SHDN
9
OT1
7
OT2
8
11
EXPOSED PAD
3003 F01
Figure 1. Block Diagram
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LT3003 OPERATIO
The LT3003 is an easy-to-use 3-channel LED ballaster. It allows three strings of LEDs to be driven in parallel with accurate LED current matching. A PWM pin is also provided allowing LED currents to be turned on and off at very low duty cycles for very wide LED dimming ranges. For reliable system thermal management, two output flags, OT1 and OT2, are provided to indicate when the junction temperature exceeds 125C. The Block Diagram in Figure 1 best illustrates the features of LT3003. The LT3003 internal bias circuitry is turned on when VIN > 3V and SHDN > 0.7V. For LED current to be active in each channel, the PWM pin must exceed 0.5V. VMAX should be connected to the highest supply in the application (see various application modes of boost, buck, buck-boost in the Typical Applications section). The LT3003 ballasting feature is achieved by using the current monitored in the LED2 channel to control the current in each of the channels LED1 and LED3. A servo loop exists for each channel LED1 and LED3 that compares the current in each channel to the LED2 reference channel. The current in LED2 channel is determined by the LED current programmed by the partner LED driver. Details of how LED current can be programmed by the partner IC are covered in the Typical Applications section using various ICs as LED drivers. Maximum fault current in each of the LT3003 LED pins is internally limited to 550mA. If any LED string experiences an open-circuit fault, all LED string currents are turned off.
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The LT3003 PWM pin has unique level-shifting circuitry to allow a simple logic-level PWM signal to turn each LED pin current on and off regardless of the VEE pin voltage. This allows very simple PWM dimming control of LED current without any need for external level-shifting components in buck and buck-boost mode applications. Care is taken to ensure low current (nano amps) in the VEE and VMAX pins 10s after PWM low edge. This feature minimizes leakage currents in each application to maximize PWM dimming ratio. Details of PWM dimming and critical parameters are given in the Applications Information section PWM Dimming. The LT3003 incorporates internal junction temperature sensing and provides two open-collector outputs, OT1 and OT2, which become active low when junction temperature exceeds 125C. OT1 is sized to pull 100A and can be used as an input to the microprocessor for system thermal management. OT2 is sized to pull 300A to defeat switching for most of LTC's LED drivers by pulling down the gm error amplifier output. LT3003 is forced to a "zero LED current state" by a special internal protection circuit when junction temperature reaches 150C. To calculate the LT3003 junction temperature, see Thermal Calculations in the Applications Information section.
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LT3003 APPLICATIO S I FOR ATIO
Input Capacitor Selection The LT3003 will typically be driven from the same input voltage used for the partner LED driver IC. The LED driver and inductor will govern the requirements for the input capacitor of the application. A ceramic input capacitor in the range of 1F to 10F will suffice in most applications. In cases where the LT3003 input voltage is derived separately from the LED driver, a 1F input capacitor should work well. LED Current Matching and VF Mismatch An LED driver programs the LED current and LT3003 actively ballasts three separate strings of LEDs. The currents in all three LED strings will be matched to better than 3%. The effect of the VF mismatch on maximum allowable LED pin currents is shown in Figure 2. VF mismatch causes increased heating within the LT3003 (see Thermal Calculation section for more information).
400 350 VLED = 3V 300 ILED1,2,3 (mA) 250 200 150 100 VIN = 3V VEE = 0V 50 VLED = TOTAL LED VF MISMATCH BETWEEN THREE CHANNELS 0 20 40 80 100 120 60 0 AMBIENT TEMPERATURE (C)
3003 F02
VLED = 0V
VLED = 1V VLED = 2V
140
Figure 2. Maximum Programmable LED Pin Currents vs Ambient Temperature
LED Pin Current Range The steady-state operational current range for each LED pin is between 100mA and 350mA. Internal protection circuitry limits absolute maximum pin current to 550mA. LED Open-Circuit Protection If any LED string is open, then currents in all three channels reduce to zero LED current. The driver chip, which supplies LED currents, should have an overvoltage clamp to protect the LT3003 from high LED pin voltages.
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PWM Dimming The LT3003 allows a wide PWM dimming range for constant color LED dimming. PWM dimming is superior to analog dimming as it preserves true color quality. PWM dimming control with the LT3003 is achieved using a simple ground referenced PWM signal with a 0.5V on/off threshold. The LEDs operate at either programmed or zero current but their average value changes with the PWM signal duty cycle. When PWM is low, LED strings are completely disconnected, resulting in higher system power efficiency. In addition, the LT3003 switches to low power standby mode ~10s after PWM low edge, resulting in higher system power efficiency. For the widest dimming range, the PWM signal should be 100Hz. The lower bound is 80Hz as the human eye is typically sensitive to flickering below 80Hz. Operating the PWM higher than 100Hz results in a reduced dimming ratio. Achieving high PWM dimming ratios require attention to circuit leakages, such as reverse bias leakage currents through the external Schottky. Hence, for high PWM dimming ratios, components should be chosen to minimize leakage currents. If the application does not require dimming, the PWM pin can be left open (unconnected) and an internal 10A source current pulls PWM high. Boost Configuration Dimming The LT3003 supports up to a 3000:1 PWM dimming ratio in boost mode. To achieve such high PWM ratios, leakages of the LED driver and other external components should be minimal. Buck Configuration Dimming The LT3003 supports up to a 3000:1 PWM dimming ratio in buck configuration. The PWM dimming in buck mode is achieved by an architecture that allows the power ground (VEE) to move with output capacitor voltage. PWM dimming control is achieved by a simple ground referenced PWM signal, whereby eliminating the need for any external level-shift component. High PWM dimming ratios require very low VEE and VMAX pin currents during the PWM off state. The LT3003
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LT3003 APPLICATIO S I FOR ATIO
VIN C1 RSENSE L1 D1 C2
+
EA SW
D1A D1B D1C
D2A D2B D2C
D3A D3B D3C
DRV LED DRIVER
LED1 PWM PWM SHDN VIN
LED2
LED3
LT3003 VEE GND
Figure 3. Boost Mode
VIN C1 RSENSE VIN D1A D1B D1C LED1 PWM VEE D2A D2B D2C LED2 D3A C1 D3B D3C LED3 LT3003 GND VIN VMAX OT1 OT2 SHDN C2
PWM L1
3003 F04
+
EA DRV LED DRIVER SW
Figure 4. Buck Mode
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uses novel circuit techniques to reduce VEE and VMAX pin currents to nano amp range ~10s after PWM low edge. This preserves the output capacitor voltage and results in higher PWM dimming ratios. Buck-Boost Configuration Dimming The LT3003 can also perform PWM dimming in buckboost mode, avoiding the need to revert to SEPIC mode solutions whenever PWM dimming is also required. The buck-boost configuration requires the PWM and SHDN pins to be tied together. This configuration can support up to a 2000:1 PWM dimming ratio.
OT1 OT2 VIN VMAX GND LT3003 VEE LED2 D1C LED1 SHDN PWM L1 D1 D1B D1A RSENSE LED3 D2C D2B D2A D3C D3B D3A VMAX OT1 OT2
3003 F03
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EA PWM SW
C2
D1
DRV LED DRIVER
3003 F05
Figure 5. Buck-Boost Mode
Overtemperature Protection The LT3003 incorporates internal junction temperature sensing and provides two open-collector outputs, OT1 and OT2, which become active low when junction temperature exceeds 125C. The active OT1 output can sink 100A of current and can be connected to system microprocessor. The active low OT2 output can sink 300A of current and can be connected to the switching regulator's gm error amplifier output to defeat switching. The LT3003 has to cool down by 6C (119C) for OT1 and OT2 outputs to reset (collector outputs high).
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LT3003 APPLICATIO S I FOR ATIO
In addition, LT3003 has an internal 150C overtemperature protection circuitry that resets the chip to zero LED current mode. This prevents the chip from continuous operation at high temperature. The chip has to cool by ~6C for it to resume normal operation (start sinking programmed LED currents) Thermal Calculations To maximize output power capability in an application without exceeding the LT3003 125C maximum operational junction temperature, it is useful to be able to calculate power dissipation within the IC. The power dissipation within the LT3003 comes from four main sources: switch DC loss, switch loss due to LED VF mismatch and input quiescent current. 1. Switch DC Loss: PSW(DC) = ILED * VLED * 3 (See (VLED1,2,3 - VEE) vs ILED Typical Performance Characteristics graph.) 2. Switch Loss due to LED VF Mismatch: PSW(DELVF) = Total VF mismatch * ILED 3. Input Quiescent Loss: PQ = (VIN - VEE) * (IQ - 1mA) + 1mA * VIN IQ =
(ILED) 3 + 3mA
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4. Total Power Dissipation: PTOT = PSW(DC) + PSW(DELVF) + PQ 5. LT3003 Junction Temperature: TJ (LT3003) = TA + JA(PTOT); [JA(PTOT) = PTOT * 35C/W]
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Example VIN = 3V; VEE = 0V; ILED = 350mA/string; * IQ =
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(350) 3 + 3 = 29.25mA
40
Total VF mismatch = 1V: * e.g., LED string 1, VF = 6V; LED string 2, VF = 5.7V; LED string 3, VF = 5.3V * Total VF mismatch = (6V - 5.7V) + (6V - 5.3V) = 1V VLED = 1.1V at ILED = 350mA (see (VLED1,2,3 - VEE) vs ILED Typical Performance Characteristics graph). 1. PSW(DC) = 3 * 350mA * (1.1V) = 1.16W 2. PSW(DELVF) = 1000mV * 350mA = 350mW 3. PQ = (3 - 0) * (29.25 - 1) + 3 * 1mA = 88mW 4. PTOT = 1.1W + 350mW + 88mW = 1.6W The LT3003 uses a thermally enhanced 10-lead MSE package. With proper soldering of the Exposed Pad to the underside of the package, combined with a full copper plane underneath the device, the thermal resistance (JA) will be about 35C/W. For an ambient temperature of TA = 25C, the junction temperature of the LT3003, for the example application described above, can be calculated as: 5. TJ (LT3003) = TA + JA (PTOT) = 25 + 35 * (1.6W) = 81C Minimizing LT3003 Internal Power Dissipation The LT3003 requires only 3V headroom between VIN and VEE. Hence, for systems with high system input voltage and low VEE (such as running multiple series LEDs in a buck configuration), it is beneficial to lower the level of VIN pin voltage (LT3003 upper rail) with an external zener to reduce power dissipation in the chip. Therefore, it is recommended to limit (VIN - VEE) to less than 10V. To achieve best performance, (VIN - VEE) should equal 3V.
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LT3003 TYPICAL APPLICATIO S
1.05A "Buck Mode" LT3003 with the LT3476
PVIN 33V MAX
VIN 3V TO 16V C1 1F 18 7 37 SHDN REF VADJ1 33 VIN CAP1 LED1 3 2 LED R1 0.1 LED
LT3476 PWM1 RT SW1 SW1 VC1 GND 39 NC 19-21, 30-32 35 29 28 1
6 R3 21k
EFFICIENCY (%)
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D1 4.7F 35V 1F 5 1 LED 2 LED 3 LED LED 1. 8 LEDs PER STRING 2. ILED = 350mA LED3 PWM 6 LED2 LT3003 VEE 10 VIN LED1 4 VMAX SHDN 9 C2 0.33F L1 10F D2 20V
OT1 7
OT2 8
GND 11
3003 TA02a
1nF C1: TDK C1608X7R1C105K C2: TAIYO YUDEN GMK212BJ334MG-T D1: DIODES INC. DFLS140 L1: TOKO A916CY-100M-P3 LED: LUMILEDS LUXEON
Efficiency
90 85 80 75 70 65 PVIN = 33V NUMBER OF LEDS = 8 * 3 = 24 60 0 200 400 600 800 TOTAL ILED (mA) 1000 1200
3003 TA02b
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LT3003 TYPICAL APPLICATIO S
330mA Boost Mode LT3003 with the LT3477
L1 4.7H C1 1F 25V 1 10 9 3 13 14 16 17 D1 R5 1.15M 1% R6 45.3k 1% C4 4.7F 50V VMAX
VIN 8V TO 16V
7 8 5 D2 1N4148W PWM Q1 2N7002 C2 22nF
C1, C3: TAIYO YUDEN TMK212BJ105MG-BR C4: MURATA GRM32ER71H475KA88L D1: DIODES INC. DFLS140 L1: SUMIDA CDRH5D16-4R7
PWM Dimming
1000 ILED = 110mA NUMBER OF LEDS = 8 * 3 = 24 100 TOTAL ILED (mA) EFFICIENCY (%) 100
10
1
0.1
1
100 1000 10 PWM DIMMING RATIO
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ISP1 ISN1 VIN IADJ1 IADJ2 SHDN LT3477
SW SW 6 FBN 18 NC 19 NC 20 NC ISP2 11
FBP VREF VC GND 15 GND 21 SS
ISN2 RT
12 2 R3 6.81k
R4 0.3 1% ILED 110mA 6 to 8 LEDs/STRING
4 C3 0.033F 3 6 LED1 PMW 2 LED2 1 LED3 VMAX 4 VMAX VIN 4V OT1 LT3003 VIN 5 C3 1F 25V 9
7
8
OT2 GND 11 VEE 10
SHDN
3003 TA03a
Efficiency
ILED = 110mA 95 NUMBER OF LEDS = 8 * 3 = 24 90 85 80 75 70 65 60 55 50 10000
3003 TA03b
8
9
10
11
12 13 VIN (V)
14
15
16
3003 TA03b
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LT3003 TYPICAL APPLICATIO S
300mA "Buck-Boost Mode" LT3003 with the LT3477
D3 1F 4 6 VMAX VEE 5 VIN LED1 1 LED9 LED10 LED11 LED12 7 GND LT3003 LED2 2 LED5 LED6 LED7 LED8 LED3 SHDN 9 PMW OT2 6 8 OT1 7 3 LED1 LED2 LED3 LED4 ILED = 100mA 10H 33F CER D1 RSENSE 0.33 280k
VIN 8V TO 16V
EFFICIENCY (%)
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ISP1 ISN1 VIN IADJ1 IADJ2 SHDN SS LT3477
SW FBN FBP VREF ISP2 ISN2 RT GND
10k
33nF CER PWM 5V 0V 100Hz
VC D2 NMOS 10nF
6.81k
3003 TA04a
3.3F 50V CER
D1: ZETEX ZLLS1000 D2: DIODES INC 1N4148 D3: PHILIPS PDZ9.1B NMOS: ZETEX 2N7002
Efficiency
80 12LEDs 78 76 74 72 ILED = 100mA 70 68
ILED = 200mA
6
8
10
12 VIN (V)
14
16
18
3003 TA04b
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LT3003 TYPICAL APPLICATIO S
1A "Buck Mode" LT3003 with the LT1618
VIN 32V C1 4.7F 50V CER RSENSE 0.05 1%, 1A
VIN 5V
C1 1F 10V CER
EFFICIENCY (%)
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ILED = 333mA
LED1 VMAX D1 14V VIN R1 1M SHDN C3 1F 50V ISN ISP VIN SHDN IADJ GND LT1618 NC SW GND
LED2
LED3 OT1 VC
LT3003
OT2 COUT 1F 50V CER
PWM VEE
L1 10F 1.5A
ZLLS1000
1N4148W VC FB Q4 2N7002 1k 220pF 10nF
3003 TA05a
PWM 100Hz 5V 500:1
Efficiency
83 82 81 80 79 78 77 0 0.2 0.4 0.6 ILED * 3 (A) 0.8 1.0
3003 TA05b
18 LEDs
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LT3003 TYPICAL APPLICATIO S
1A Buck Mode LT3003 with the LT3475
R1 20k CIN1 4.7F 50V 5 20 3 COUT1 2.2F 16V LED7 LED8 LED9 D2 B240A D1 1N4448W L1 10H SUMIDA 6 16 SHDN PWM2 BOOST2 11 8
VIN 24V
LED1 LED2 LED3 LT3003 VMAX VIN GND 20V C3 1F 50V
SHDN OT2 OT1 PWM PWM1 100Hz 2000:1 PWM DIMMING VC
EFFICIENCY (%)
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VIN VIN PWM1 BOOST1
1 C1 0.22F X5R 4 2 17
OUT1
OUT2
10
SW1 LED1 REF
LT3475
SW2 LED2
7 9
LED4
LED5
LED6
LED1
LED2
LED3
R8 2.0k
R4 1.0k
19 18
VADJ1 VC1 GND 15 RT 14
VADJ2 VC2 GND 21
12 13
330mA x3 3S 3P LUXEON I WHITE VEE
C3 3300pF
R10 10k C5 0.1F R13 1.0M C7 220pF
R12 11.8k 1%
3003 TA06a
fSW = 1MHz
Q3 2N7002
Efficiency
100 95 90 85 80 75 70 65 65 55 50 0 0.2 0.6 0.8 0.4 TOTAL ILED (A) 1.0 1.2
3003 TA06b
3003f
LT3003 PACKAGE DESCRIPTIO U
MSE Package 10-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1664)
BOTTOM VIEW OF EXPOSED PAD OPTION 0.889 0.127 (.035 .005) 1 2.06 0.102 (.081 .004) 1.83 0.102 (.072 .004)
2.794 0.102 (.110 .004)
5.23 (.206) MIN
2.083 0.102 3.20 - 3.45 (.082 .004) (.126 - .136)
10
0.50 0.305 0.038 (.0197) (.0120 .0015) BSC TYP RECOMMENDED SOLDER PAD LAYOUT
3.00 0.102 (.118 .004) (NOTE 3) 10 9 8 7 6
0.497 0.076 (.0196 .003) REF
4.90 0.152 (.193 .006) 0.254 (.010) GAUGE PLANE 0.53 0.152 (.021 .006) DETAIL "A" 0.18 (.007) SEATING PLANE 1.10 (.043) MAX DETAIL "A" 0 - 6 TYP 12345
3.00 0.102 (.118 .004) (NOTE 4)
0.86 (.034) REF
0.17 - 0.27 (.007 - .011) TYP
NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
0.50 (.0197) BSC
0.127 0.076 (.005 .003)
MSOP (MSE) 0603
3003f
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT3003 RELATED PARTS
PART NUMBER LT1618 LT1932 LT1942 DESCRIPTION Constant-Current/Constant-Voltage DC/DC Converter Constant Current,1.2MHz, High Efficiency White LED Boost Regulator Quad DC/DC Converter for Triple Output TFT Supply Plus Boost LED Driver, with a 2-Channel Ballaster 36V, 2MHz, Dual 1.5A Step-Down LED Driver 3A, 3.5mHz, Constant-Current DC/DC Converter with Dual Rail Sense. Can Drive LEDs in Boost, Buck and Buck-Boost Configurations 4.5A Constant Current BOOST LED Driver with PWM 3A, 3.5MHz, 42V Full Featured Boost/Inverter Converter with Soft-Start 36V, 2MHz, Step-Down 1A LED Driver Multi-Display LED Controller, Step-Up/Step-Down Fractional Charge Pump, Independent Current and Dimming Control PWM LED Power and Boost, Flyback and SEPIC Controller COMMENTS Drives 20 White LEDs from Li-Ion, 10-Lead MS Package VIN: 1V to 10V, VOUT(MAX) = 34V, IQ = 1.2mA, ISD < 1A, ThinSOTTM Package TFT Supply: Three Switching Regulators (Two Boost, One Inverting) LED Supply: Up to Two Strings of 10 LEDs. VIN: 2.6V to 16V, VOUT(MAX) = 45V, IQ = 7mA, ISD < 1A, Low Profile QFN package. VIN: 4V to 36V, 200kHz to 2MHz, TSSOP20E Package, 3000:1 Dimming VIN: 2.5V to 25V, VOUT(MAX) = 42V, ISD < 1A, QFN/TSSOP Packages
LT3475 LT3477
LT3478 LT3479 LT3474 LTC3205 LTC3783
VIN: 2.7V to 36V, VOUT(MAX) = 40V, ILED(MAX) = 1.05A, ISD < 5A, FE16 Package VIN: 2.5V to 24V, VOUT(MAX) = 40V, IQ = 5mA, ISD < 1A, DFN/TSSOP Packages VIN: 4V to 36V, 200kHz to 2MHz, TSSOP16E Package, 400:1 Dimming VIN: 2.8V to 4.5V, 800MHz, QFN Package VIN: 3.6V to 36V, 300kHz, DFN, TSSOP16E Package, 3000:1 Dimming
ThinSOT is a trademark of Linear Technology Corporation.
3003f
16 Linear Technology Corporation
(408) 432-1900 FAX: (408) 434-0507
LT 1006 * PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2006

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