LT3003EMSE

FEATURES ■ ■ ■ ■ ■ ■ ■ ■ LT3003 3-Channel LED Ballaster with PWM DESCRIPTION The LT®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, buck 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®3783 Thermally Enhanced 10-Pin MSOP Package APPLICATIONS ■ ■ ■ ■ High Power LED Ballaster Automotive Lighting Video Cameras TFT LCD Backlighting TYPICAL APPLICATION Buck Mode LT3003 with the LT3476 PVIN 32V Efficiency 90 1µF 0.1Ω 8 × 3 = 24 LEDs 350mA PER STRING 85 80 75 70 65 0.33µF LED1 VMAX SHDN PWM DIMMING PWM GND LED2 LT3003 OT1 OT2 LED3 VIN 1µF VEE EFFICIENCY (%) CAP LED VIN 3V TO 16V VIN 10µF PWM VC 1nF SW SIMPLIFIED LT3476 GND 10µH 60 PVIN = 32V NUMBER OF LEDS = 8 × 3 = 24 0 1000 400 600 800 200 TOTAL LED CURRENT (mA) 1200 3003 TA01a 3003 TA01b 3003fa 1 LT3003 ABSOLUTE MAXIMUM RATINGS (Note 1) PACKAGE/ORDER INFORMATION 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) ........................................ –40°C to 125°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C MSE PACKAGE 10-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 35°C/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 = 25°C. 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 µA µA µA nA V % % V mA µA V µs µA °C °C µA 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 3003fa 2 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 = 25°C. 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 µA µA 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 0°C to 85°C junction temperature. Specifications over the –40°C to 125°C 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 125°C 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 = 25°C. Note 5: Guaranteed by design. TYPICAL PERFORMANCE 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) TA = 25°C unless otherwise noted. VEE Pin Current (Out of the Pin) vs Temperature 500 450 VEE PIN CURRENT • –1 (nA) 400 350 300 250 200 150 100 50 300 350 3003 G02 VIN Quiescent Current vs ILED TJ = 27°C 10µs AFTER PWM = 0 ILED1,3 vs ILED2 (%) 0 50 25 0 75 100 –50 –25 JUNCTION TEMPERATURE (°C) 125 3003 G01 3003 G03 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 10µs AFTER PWM = 0 VIN SHUTDOWN CURRENT (µA) 7 6 5 4 3 2 1 VIN Shutdown Current vs Temperature SHDN = 0 1150 1100 (VLED1,2,3 – VEE) (mV) 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 3003fa 3 LT3003 TYPICAL PERFORMANCE CHARACTERISTICS VIN Quiescent Current vs ILED 35 VIN QUIESCENT CURRENT (mA) VIN SHUTDOWN CURRENT (µA) 30 25 20 15 10 5 0 50 100 150 250 200 ILED (mA) 300 350 3003 G07 TA = 25°C 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 PIN FUNCTIONS 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: 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: 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 10µA 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 100µA from the pin when the junction temperature exceeds 125°C. The part has to cool down by 6°C for the flag to reset; ideal for providing an overtemperature flag to the system microprocessor. OT2 (Pin 8): Overtemperature Output. OT2 Pulls 300µA from the pin when the junction temperature exceeds 125°C. The part has to cool down by 6°C 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 = 4µA for SHDN = 0V. • Boost: Connect to System Shutdown Signal or VIN • Buck Mode: Connect to System Shutdown Signal or VIN • Buck-Boost Mode: If PWM dimming, connect to PWM (Pin 6); if no PWM dimming, connect to system shutdown signal or VIN 3003fa 4 LT3003 PIN FUNCTIONS VEE (Pin 10): Lower Rail. • Boost: 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 thermal resistance and increase the power capability of the LT3003. BLOCK DIAGRAM 1 LED1 4 VMAX VIN 2 LED2 3 LED3 B1 + – B2 + – B3 VEE B1 B2 B3 10 PWM LOGIC + – 3V VIN 5 VEE 6 PWM + 0.5V + – BIAS BG THERMAL SHUTDOWN BG 125°C 150°C 0.7V SHDN 9 – OT1 7 OT2 8 11 EXPOSED PAD 3003 F01 Figure 1. Block Diagram 3003fa 5 LT3003 OPERATION 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 125°C. 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 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. 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 mode and buck-boost mode applications. Care is taken to ensure low current (nano amps) in the VEE and VMAX pins 10µs 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 125°C. OT1 is sized to pull 100µA and can be used as an input to the microprocessor for system thermal management. OT2 is sized to pull 300µA 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 150°C. To calculate the LT3003 junction temperature, see Thermal Calculations in the Applications Information section. 3003fa 6 LT3003 APPLICATIONS INFORMATION Input Capacitor Selection The LT3003 is typically driven from the same input voltage used for the partner LED driver IC. The LED driver and inductor govern the requirements for the input capacitor of the application. A ceramic input capacitor in the range of 1µF to 10µF works for most applications. In cases where the LT3003 input voltage is derived separately from the LED driver, a 1µF input capacitor works well. LED Current Matching An LED driver programs the LED current and LT3003 actively ballasts three separate strings of LEDs. The currents in all three channels will be matched to better than ±3%. To achieve best current matching, (VIN – VEE) should be between 3V and 10V. A low (VIN – VEE) also minimizes LT3003 internal power dissipation (see Thermal Calculation section for more information). 10 ILED2 = 350mA ∆VLED = 1.4V PWM Dimming The LT3003 has 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 brightness changes with the PWM signal duty cycle. When PWM is low, LED strings are completely disconnected. In addition, the LT3003 switches to low power standby mode ~10µs after PWM low edge, resulting in higher system power efficiency. For the widest dimming range, the PWM signal should be 100Hz. The human eye is typically sensitive to flickering below ~80Hz. Operating the PWM higher than 100Hz results in a reduced PWM 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 an application does not require PWM dimming, the PWM pin can be left open (unconnected) and an internal 10µA source current pulls PWM high. Boost PWM Dimming 8 ILED1,3 vs ILED2 (%) 6 4 2 0 3 6 9 12 15 18 21 24 27 30 33 36 VIN – VEE (V) 3003 F02 Figure 2. ILED Matching vs (VIN – VEE) The LT3003 supports up to a 3000:1 PWM dimming ratio with a 100Hz PWM dimming frequency. To achieve such high PWM ratios, leakages of the LED driver and other external components should be minimal. Buck Mode: PWM Dimming The LT3003 supports up to a 3000:1 PWM dimming ratio in buck mode. The PWM dimming in buck mode is achieved by an architecture that allows the LT3003 power ground (VEE) to move with output capacitor voltage. PWM dimming control is achieved by a simple ground referenced PWM signal, eliminating the need for any external levelshift component. High PWM dimming ratios require very low VEE and VMAX pin currents during the PWM off state. The LT3003 3003fa 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. The driver chip, which supplies LED current, should have an overvoltage clamp to protect the LT3003 from high LED pin voltages. 7 LT3003 APPLICATIONS INFORMATION VIN C1 RSENSE L1 D1 C2 uses novel circuit techniques to reduce VEE and VMAX pin currents to nano amp range ~10µs after PWM low edge. This preserves the output capacitor voltage and results in higher PWM dimming ratios. Buck-Boost Mode: PWM Dimming The LT3003 can also perform PWM dimming in buck-boost mode. 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. + EA SW D1A D1B D1C D2A D2B D2C D3A D3B D3C DRV LED DRIVER LED1 PWM PWM SHDN VIN LED2 LED3 VMAX OT1 OT2 3003 F03 LT3003 VEE GND OT1 OT2 VIN VMAX GND LT3003 LED3 D3C D3B D3A D2C LED2 D1C LED1 D2B D2A Figure 3. Boost Mode VIN C1 RSENSE VIN C1 D1A D1B D1C LED1 PWM VEE D2A D2B D2C LED2 D3A D3B D3C LED3 LT3003 GND VIN VMAX OT1 OT2 SHDN VEE D1B D1A RSENSE SHDN PWM L1 D1 + EA PWM DRV LED DRIVER SW C2 3003 F05 Figure 5. Buck-Boost Mode Overtemperature Protection PWM L1 C2 D1 3003 F04 + EA DRV LED DRIVER SW Figure 4. Buck Mode The LT3003 incorporates internal junction temperature sensing and provides two open-collector outputs, OT1 and OT2, which become active low when junction temperature exceeds 125°C. The active OT1 output can sink 100µA of current and can be connected to system microprocessor. The active low OT2 output can sink 300µA 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 6°C (119°C) for OT1 and OT2 outputs to reset (collector outputs high). 3003fa 8 LT3003 APPLICATIONS INFORMATION In addition, LT3003 has an internal 150°C overtemperature protection circuitry that resets the chip to zero LED current mode. This prevents the chip from continuous operation at high temperature. Thermal Calculations To maximize output power capability in an application without exceeding the LT3003 125°C 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 VLED 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 VLED Mismatch: PSW(ΔVLED) = Total VLED mismatch • ILED 3. Input Quiescent Loss: PQ = (VIN – VEE) • (IQ – 1mA) + 1mA • VIN IQ = 3 • ILED + 3mA 40 Example VIN = 3V; VEE = 0V; ILED = 350mA/string; • IQ = 3 • 350mA + 3mA = 29.25mA 40 Total VLED mismatch = 1V: • e.g., LED string 1 voltage drop = 6V; LED string 2 voltage drop = 5.7V; LED string 3 voltage drop = 5.3V • Total VLED mismatch = (6V – 5.7V) + (6V – 5.3V) = 1V VLED = 1.1V at ILED = 350mA (see (VLED – VEE) vs ILED Typical Performance Characteristics graph). 1. PSW(DC) = 3 • 350mA • (1.1V) = 1.16W 2. PSW(LED) = 1000mV • 350mA = 350mW 3. PQ = (3 – 0) • (29.25 – 1)mA + 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 (θJA) is about 35°C/W. For an ambient temperature of TA = 25°C, the junction temperature of the LT3003, for the example application described above, can be calculated as: 5. TJ = TA + θJA • PTOT = 25°C + 35°C/W • 1.6W = 81°C Minimizing LT3003 Internal Power Dissipation The LT3003 requires at least 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 Mode), 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. 4. Total Power Dissipation: PTOT = PSW(DC) + PSW(ΔVLED) + PQ 5. LT3003 Junction Temperature: TJ (LT3003) = TA + θJA(PTOT); θJA(PTOT) = PTOT • 35°C/W 3003fa 9 LT3003 TYPICAL APPLICATIONS 1.05A Buck Mode LT3003 with the LT3476 PVIN 32V D1 4.7µF 35V 1µF 5 4 VMAX SHDN 9 C2 0.33µF L1 10µH D2 20V VIN 3V TO 16V C1 1µF 18 7 37 SHDN REF VADJ1 33 VIN CAP1 LED1 3 2 LED R1 0.1Ω LED 1 LED 2 LED 3 VIN LED1 LED2 LT3003 VEE 10 LT3476 PWM1 RT SW1 SW1 VC1 GND 39 NC 19-21, 30-32 35 29 28 1 LED LED 8 LEDs PER STRING; 350mA PER STRING LED3 PWM 6 OT1 7 OT2 8 GND 11 6 R3 21k 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 60 PVIN = 33V NUMBER OF LEDS = 8 × 3 = 24 0 1000 400 600 800 200 TOTAL LED CURRENT (mA) 1200 EFFICIENCY (%) 3003 TA02b 3003fa 10 LT3003 TYPICAL APPLICATIONS 330mA Boost LT3003 with the LT3477 L1 4.7µH C1 1µF 25V 1 10 9 3 13 14 16 17 D1 R5 1.15M 1% R6 45.3k 1% C4 4.7µF 50V VOUT VIN 8V TO 16V ISP1 ISN1 VIN IADJ1 IADJ2 SHDN LT3477 SW SW 6 FBN 18 NC 19 NC 20 NC ISP2 11 7 8 5 D2 1N4148W PWM Q1 2N7002 C2 22nF FBP VREF VC GND 15 GND 21 SS ISN2 RT 12 2 R3 6.81k R4 0.3Ω 1% ILED 110mA PER STRING 6 to 8 LEDs PER STRING 4 C3 0.033µF 6 3 LED1 PWM 2 LED2 1 LED3 VMAX 4 VOUT VIN 4V OT1 LT3003 VIN 5 C3 1µF 25V 9 C1, C3: TAIYO YUDEN TMK212BJ105MG-BR C4: MURATA GRM32ER71H475KA88L D1: DIODES INC. DFLS140 L1: SUMIDA CDRH5D16-4R7 7 8 OT2 GND 11 VEE 10 SHDN 3003 TA03a PWM Dimming 1000 ILED = 110mA PER STRING NUMBER OF LEDS = 8 × 3 = 24 100 TOTAL ILED (mA) EFFICIENCY (%) 100 Efficiency ILED = 110mA PER STRING 95 NUMBER OF LEDS = 8 × 3 = 24 90 85 80 75 70 65 10 1 60 55 0.1 50 1 100 1000 10 PWM DIMMING RATIO 10000 3003 TA03b 8 9 10 11 12 13 VIN (V) 14 15 16 3003 TA03b 3003fa 11 LT3003 TYPICAL APPLICATIONS 300mA Buck-Boost Mode LT3003 with the LT3477 D3 1µF 4 6 VMAX VEE 5 VIN LED1 1 LED9 LED10 LED11 LED12 7 GND LT3003 LED2 2 LED5 LED6 LED7 LED8 LED3 SHDN 9 PWM OT2 6 8 OT1 7 3 LED1 LED2 LED3 LED4 ILED = 100mA 10µH 33µF CER D1 RSENSE 0.33Ω 280k 3.3µF 50V CER VIN 8V TO 16V 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 D1: ZETEX ZLLS1000 D2: DIODES INC 1N4148 D3: PHILIPS PDZ9.1B NMOS: ZETEX 2N7002 Efficiency 80 78 76 74 72 ILED = 100mA 70 68 NUMBER OF LEDS = 4 × 3 = 12 EFFICIENCY (%) ILED = 200mA 6 8 10 12 VIN (V) 14 16 18 3003 TA04b 3003fa 12 LT3003 TYPICAL APPLICATIONS 1A Buck Mode LT3003 with the LT1618 VIN 32V C1 4.7µF 50V CER RSENSE 0.05Ω 1%, 1A ILED = 333mA PER STRING LED1 VMAX D1 14V VIN R1 1M SHDN C3 1µF 50V ISN ISP VIN 5V VIN 1µF 10V CER SHDN IADJ GND LT1618 NC SW GND LED2 LED3 OT1 LT3003 OT2 COUT 1µF 50V CER PWM VEE L1 10µH 1.5A ZLLS1000 1N4148W VC FB Q4 2N7002 1k 220pF 10nF 3003 TA05a PWM 100Hz, 5V 500:1 MAX PWM DIMMING RATIO Efficiency 83 82 81 80 79 78 77 0 0.2 0.4 0.6 0.8 TOTAL LED CURRENT (A) 1.0 3003 TA05b NUMBER OF LEDS = 6 × 3 = 18 EFFICIENCY (%) 3003fa 13 LT3003 TYPICAL APPLICATIONS 1A Buck LT3003 with the LT3475 R1 20k CIN1 4.7µF 50V 5 20 3 COUT1 2.2µF 16V LED7 LED8 LED9 D2 B240A D1 1N4448W L1 10µH SUMIDA 6 16 SHDN PWM2 BOOST2 11 8 ONE OF TWO CHANNELS SHOWN VIN 24V VIN VIN PWM1 BOOST1 1 C1 0.22µF X5R 4 2 17 OUT1 OUT2 10 SW1 LED1 REF LT3475 SW2 LED2 7 9 SECOND CHANNEL 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 PER STRING 3S 3P LUXEON I WHITE LED1 LED2 LED3 LT3003 VMAX VIN GND 20V C3 1µF 50V VEE SHDN OT2 OT1 PWM PWM1 100Hz 2000:1 MAX PWM DIMMING RATIO C3 3300pF R10 10k C5 0.1µF R13 1.0M C7 220pF R12 11.8k 1% 3003 TA06a fSW = 1MHz Q3 2N7002 Efficiency 100 95 90 EFFICIENCY (%) 85 80 75 70 65 65 55 50 0 0.2 0.6 0.8 1.0 0.4 TOTAL LED CURRENT (A) 1.2 3003 TA06b 3003fa 14 LT3003 PACKAGE DESCRIPTION MSE Package 10-Lead Plastic MSOP (Reference LTC DWG # 05-08-1664) BOTTOM VIEW OF EXPOSED PAD OPTION 2.794 ± 0.102 (.110 ± .004) 0.889 ± 0.127 (.035 ± .005) 1 2.06 ± 0.102 (.081 ± .004) 1.83 ± 0.102 (.072 ± .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 3003fa 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 < 1µA, 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 < 1µA, 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 < 1µA, QFN/TSSOP Packages LT3475 LT3477 LT3478 LT3479 LT3474 LTC3205 LTC3783 VIN: 2.7V to 36V, VOUT(MAX) = 40V, ILED(MAX) = 1.05A, ISD < 5µA, FE16 Package VIN: 2.5V to 24V, VOUT(MAX) = 40V, IQ = 5mA, ISD < 1µA, 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. 3003fa 16 Linear Technology Corporation (408) 432-1900 ● FAX: (408) 434-0507 ● LT 0107 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 www.linear.com © LINEAR TECHNOLOGY CORPORATION 2006