3595

LT3595 16 Channel Buck Mode LED Driver FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTION The LT®3595 is a high performance LED Driver designed to drive sixteen independent channels of up to 10 LEDs at currents up to 50mA. Series connection of the LEDs provides identical LED currents resulting in uniform brightness. Power switches, Schottky diodes, and compensation components are all internal, providing a small converter footprint and lower component cost. The high 2MHz switching frequency permits the use of tiny, low profile inductors and capacitors. A fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltage. A single external resistor sets the LED current for all sixteen channels, and dimming is then controlled for each channel by pulse width modulating the individual PWM pins. Relative current matching among the sixteen drivers is 8% and the PWM dimming range is 5000:1. The part is available in a 5mm × 9mm × 0.75mm 56-pin QFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. 4.5V to 45V Input Supply Range Up to 50mA LED Current per Channel 100mA, 45V Internal Switches 8% Relative LED Current Match at 20mA 16 Independent LED Channels 5000:1 True Color PWMTM Dimming Range LEDs Disconnected in Shutdown Internal Schottky Diodes Low Quiescent Current 2MHz Switching Frequency RSET Pin Sets Master LED Current Typical Efficiency: 92% Open LED Detection and Thermal Protection 56-Pin 5mm × 9mm × 0.75mm QFN Package APPLICATIONS ■ ■ ■ LED Video Billboards LCD Televisions Stadium and Advertising Displays TYPICAL APPLICATION 16-Channel LED Driver (Three LEDs per Channel), 20mA Current VIN 15V TO 45V 10μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF VPWM 5V/DIV 5000:1 PWM Dimming at 100Hz 100μH 100μH 100μH 100μH 100μH 100μH 100μH VCC 100k 100μH LED BRIGHTNESS CONTROL VCC 3V TO 5.5V 10μF 100μH 100μH 100μH 100μH 100μH 100μH 100μH 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 100μH 0.47μF 3595 TA01 75.0k L1 SW1 OPENLED PWM1 PWM2 PWM3 PWM4 PWM5 PWM6 PWM7 PWM8 SHDN VCC L16 SW16 L2 SW2 SW3 L3 SW4 L4 L5 SW5 L6 SW6 SW7 L7 SW8 L8 ISW 20mA/DIV LT3595 L15 SW15 VIN SW14 L14 SW13 L13 L12 SW12 L11 SW11 VIN SW10 L10 PWM9 PWM10 PWM11 PWM12 PWM13 PWM14 PWM15 PWM16 GND RSET SW9 L9 LED BRIGHTNESS CONTROL ILED 10mA/DIV 400ns/DIV VIN = 15V 3 LEDS AT 20mA T = 10ms TON = 2μs 3595 TA01b 3595f 1 LT3595 ABSOLUTE MAXIMUM RATINGS (Note 1) PIN CONFIGURATION TOP VIEW PWM16 PWM15 PWM14 PWM13 PWM4 PWM3 PWM2 PWM7 PWM1 46 L1 45 SW1 44 L2 43 SW2 42 NC 41 SW3 40 L3 39 SW4 57 38 L4 37 L5 36 SW5 35 L6 34 SW6 33 NC 32 SW7 31 L7 30 SW8 29 L8 19 20 21 22 23 24 25 26 27 28 PWM9 PWM10 PWM11 PWM12 PWM5 PWM6 OPENLED PWM8 SHDN RSET VCC Input Voltage (VIN) ....................................................45V L1-16 Voltage ...........................................................45V Supply Voltage (VCC) ..................................................6V RSET, ⎯O⎯P⎯E⎯N⎯L⎯E⎯D , PWM1-16, ⎯S⎯H⎯D⎯N Voltage ...............6V Operating Junction Temperature Range (Note 2) ...............................................–40°C to 85°C Maximum Junction Temperature .......................... 125°C Storage Temperature Range...................–65°C to 125°C 56 55 54 53 52 51 50 49 48 47 L16 1 SW16 2 L15 3 SW15 4 VIN 5 SW14 6 L14 7 SW13 8 L13 9 L12 10 SW12 11 L11 12 SW11 13 VIN 14 SW10 15 L10 16 SW9 17 L9 18 UHH PACKAGE 56-LEAD (5mm × 9mm) PLASTIC QFN TJMAX = 125°C, θJA = 31°C/W, θJC = 0.5°C/W EXPOSED PAD (PIN 57) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH LT3595EUHH#PBF TAPE AND REEL LT3595EUHH#TRPBF PART MARKING 3595 PACKAGE DESCRIPTION 56-Lead (5mm × 9mm) Plastic QFN TEMPERATURE RANGE –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 3595f 2 LT3595 ELECTRICAL CHARACTERISTICS PARAMETER VIN Operating Voltage VCC Operating Voltage VCC Input Under Voltage Lockout IVIN Quiescent Current ON, No Switching IVIN Quiescent Current in Shutdown IVCC Quiescent Current ON, No Switching IVCC Quiescent Current in Shutdown IL1-16 Output Current Accuracy Switching Frequency Maximum Duty Cycle Switch Current Limit Switch VCESAT Switch Leakage Current Schottky Forward Drop Schottky Leakage Current ⎯S⎯H⎯D⎯N, PWM1-16 Input Low Voltage ⎯S⎯H⎯D⎯N, PWM1-16 Input High Voltage ⎯S⎯H⎯D⎯N Pin Bias Current PWM1-16 Pin Bias Current ⎯OP⎯E⎯N⎯L⎯E⎯D Pin Voltage ⎯ ⎯O⎯P⎯E⎯N⎯L⎯E⎯D Pin Input Leakage Current ⎯SH⎯D⎯N = 3.3V ⎯ PWM1-16 = 3.3V VCC = 3.3V, I⎯O⎯P⎯E⎯N⎯L⎯E⎯D = 200μA ⎯O⎯P⎯E⎯N⎯L⎯E⎯D = 3.3V 1.6 35 0.1 0.12 0.1 1 1 ISW1-16 = 50mA VSW1-16 = 45V ISCHOTTKY = 50mA VIN = 45V, VSW1-16 = 0.7V, ⎯S⎯H⎯D⎯N = 0V ● ● The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = 45V, VCC = 3.3V, PWM = ⎯S⎯H⎯D⎯N = ⎯O⎯P⎯E⎯N⎯L⎯E⎯D = 3.3V, RSET = 75kΩ, GND = 0V, unless otherwise noted. CONDITIONS MIN 4.5 3 2.6 VIN = 45V VIN = 45V, ⎯S⎯H⎯D⎯N = 0V VCC = 3.3V VCC = 3.3V, ⎯S⎯H⎯D⎯N = 0V RSET = 75.0kΩ 18.4 1.6 78 90 0.25 15 17 3 20 2 83 120 450 0.1 0.8 0.1 4 0.4 6 150 10 21.6 2.4 40 5.5 2.9 TYP MAX UNITS V V V mA μA mA μA mA MHz % mA mV μA V μA V V μA μA V 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 LT3595 is guaranteed to meet performance specifications from 0°C to 85°C junction temperature. Specifications over the –40°C to 85°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. 3595f 3 LT3595 TYPICAL PERFORMANCE CHARACTERISTICS Switching Waveforms 10 LEDS VSW1 50V/DIV 10 LEDS IL1 50mA/DIV 5 LEDS VSW2 50V/DIV 5 LEDS IL2 50mA/DIV VIN = 45V ILED = 20mA PWM Dimming Waveforms (1000:1) PWM 5V/DIV PWM Dimming Waveforms (10:1) PWM 5V/DIV IL 20mA/DIV ILED 20mA/DIV 400ns/DIV 3595 G01 IL 20mA/DIV ILED 20mA/DIV 2μs/DIV 3595 G02 2ms/DIV 3595 G03 VIN = 40V PWM FREQUENCY = 100Hz 10 LEDS AT 20mA TON = 10μs VIN = 40V PWM FREQUENCY = 100Hz 10 LEDS AT 20mA TON = 1ms LED Current vs PWM Duty Cycle Wide Dimming Range (5000:1) 100 VIN = 45V 10 LEDS AT 20mA PWM FREQUENCY = 100Hz LED CURRENT (mA) 60 50 40 30 20 10 0 LED Current vs RSET Resistance 2.0 VIN Quiescent Current T = 125°C 1.6 VIN CURRENT (mA) T = 25°C T = – 40°C 10 LED CURRENT (mA) 1 1.2 0.1 0.8 0.01 0.4 0.001 0.01 0.1 10 1 DUTY CYCLE (%) 100 3595 G04 0 25 50 75 100 125 RSET RESISTANCE (kΩ) 150 3595 G05 0 10 20 30 VIN (V) 40 50 3595 G06 VCC Quiescent Current 20 18 16 VCC CURRENT (mA) 14 12 10 8 6 4 2 0 0 1 2 4 3 VCC (V) 5 6 7 3595 F07 ⎯S⎯H⎯D⎯N Pin Bias Current 100 T = 25°C T = –40°C ISHDN (μA) 80 T = 25°C 60 T = 125°C T = –40°C VCC = 3.3V T = 125°C 40 20 0 0 1 2 3 4 VSHDN (V) 5 3595 F08 6 3595f 4 LT3595 TYPICAL PERFORMANCE CHARACTERISTICS Current Limit vs Temperature 150 SWITCHING FREQUENCY (MHz) 140 CURRENT LIMIT (mA) 130 120 110 100 90 –50 –25 2.4 SCHOTTKY LEAKAGE CURRENT (μA) 2.3 2.2 2.1 2.0 1.9 1.8 1.7 50 25 75 0 TEMPERATURE (°C) 100 125 1.6 –50 –25 50 25 75 0 TEMPERATURE (°C) 100 125 Switching Frequency vs Temperature 1.4 1.2 1.0 Schottky Leakage Current vs Temperature VIN = 45V 0.8 0.6 VIN = 24V 0.4 0.2 0 –50 –25 VIN = 4.5V 50 25 75 0 TEMPERATURE (°C) 100 125 3595 G09 3595 G10 3595 G11 Switch Saturation Voltage (VCESAT) 700 600 500 400 300 200 100 0 0 20 40 60 80 100 SWITCH CURRENT (mA) T = 125°C T = –40°C T = 25°C SCHOTTKY FORWARD CURRENT (mA) SWITCH SATURATION VOLTAGE (mV) 100 Schottky Forward Voltage Drop 80 60 T = 125°C 40 T = 25°C 20 T = – 40°C 0 0 0.2 0.6 0.8 0.4 SCHOTTKY FORWARD DROP (V) 1 3595 G13 Transient Response VSHDN 5V/DIV VSW 50V/DIV ISW 50mA/DIV ILED 20mA/DIV 100μs/DIV VIN = 45V 10 LEDS AT 20mA 3595 G14 ⎯OP⎯E⎯N⎯L⎯E⎯D Waveforms ⎯ ILED CH 1 20mA/DIV OPENLED 5V/DIV VSW CH 1 50V/DIV ILED CH 2 20mA/DIV 20μs/DIV VIN = 45V 10 LEDS AT 20mA 3595 G15 3595f 5 LT3595 PIN FUNCTIONS L1-16 (Pins 1, 3, 7, 9, 10, 12, 16, 18, 29, 31, 35, 37, 38, 40, 44, 46): LED Pins. Connection point for the anode of the highest LED in each string. SW1-16 (Pins 2, 4, 6, 8, 11, 13, 15, 17, 30, 32, 34, 36, 39, 41, 43, 45): Switch Pins. Minimize trace area at these pins to minimize EMI. Connect the inductors to these pins. VIN (Pins 5, 14): 4.5V to 45V Input Supply Pin. Must be locally bypassed. Both VIN pins must be tied together. PWM1-16 (Pins 19-22, 25-28, 47-50, 53-56): Input Pin for LED Dimming Function. The rising edge of each channel must be synchronized. ⎯OP⎯E⎯N⎯L⎯E⎯D (Pin 23): Open Collector Output for Reporting ⎯ Faults. If any channel experiences an open LED connection, the ⎯O⎯P⎯E⎯N⎯L⎯E⎯D pin is pulled low. ⎯S⎯H⎯D⎯N (Pin 24): Shutdown. Tie to 1.6V or greater to enable the device. Tie below 0.4V to turn off the device. NC (Pins 33, 42): No Connect. Connect these pins to ground. RSET (Pin 51): External Resistor to Set the Master LED Current. The LED current is equal to: ILED = 1 . 21V • 1240 R SET where RSET is the value of the external resistor. Use a kelvin for ground metal. VCC (Pin 52): 3.3V Input Supply. Must be locally bypassed. Exposed Pad (Pin 57): Ground. The Exposed Pad must be soldered to PCB. Use wide metal from backtab to the grounds of the input capacitors on VCC and VIN . 3595f 6 LT3595 BLOCK DIAGRAM CIN 10μF PWM1-16 52 VCC 3.3V C1 10μF VCC VREG VREG DFC CONTROL 1 CHANNEL 16X 24 51 RSET SHDN RSET REF V/I PWM SW1-16 COUT1-16 0.47μF VIN VIN L1-16 – + R S Q L1-16 100μH Σ ISNS + – GND 57 RAMP GENERATOR OPENLED 2MHz OSCILLATOR CONTROL 23 3595 BD 3595f 7 LT3595 OPERATION The LT3595 uses a constant-frequency, current mode control scheme to provide excellent line and load regulation. Operation is best understood by referring to the Block Diagram. The oscillator, V-I converter and internal regulator are shared by the sixteen converters. The control circuitry, power switches, PWM comparators and dimming control (DFC) are identical for all converters. The LT3595 enters shutdown mode when the ⎯S⎯H⎯D⎯N pin is lower than 400mV. If the ⎯S⎯H⎯D⎯N pin is above 1.6V, then the LT3595 turns on. At the start of each oscillator cycle, the power switch is turned on. Current ramps up through the output capacitor, the inductor, and the switch to ground. When the voltage across the output capacitor is larger than the LEDs’ forward voltage, current flows through the LEDs. When the switch is on, a voltage proportional to the switch current is added to a stabilizing ramp and the resulting sum is fed into the positive terminal of the PWM comparator. When this voltage exceeds the level at the negative input of the PWM comparator, the PWM logic turns off the power switch. The level at the negative input of the PWM comparator is set by the error amplifier output. This voltage is set by the LED current and the bandgap reference. In this manner, the error amplifier sets the correct peak current level in the inductor to keep the LED output current in regulation. The external RSET resistor is used to program the LED current from 10mA to 50mA. Input Voltage Range The minimum input voltage required to generate a specific output voltage in an LT3595 application is limited by its 4.5V input voltage or by its maximum duty cycle. The duty cycle is the fraction of time that the internal switch is on divided by the total period. It is determined by the input voltage and the voltage across the LEDs: DC = VLED + VD VVIN − VCESAT + VD where VLED is the voltage drop across the LEDs, VD is the Schottky forward drop, and VCESAT is the saturation voltage of the internal switch. This leads to a minimum input voltage of: VIN(MIN) = VLED + VD + VCESAT − VD DCMAX where DCMAX is the minimum rating of maximum duty cycle. The maximum input voltage is limited by the absolute maximum rating of 45V. Pulse-Skipping At low duty cycles, the LT3595 may enter pulse-skipping mode. Low duty cycle occurs at higher input voltages and lower LED count. The LT3595 can drive currents without pulse-skipping provided the voltage across the LED string is greater than 15% of the input supply voltage. If the current decreases to the point that the LED voltage is less than 15% of the input supply, the device may begin skipping pulses. This will result in some low frequency ripple, although the LED current remains regulated on an average basis down to 10mA. 3595f 8 LT3595 OPERATION Discontinuous Current Mode The LT3595 can drive a 10-LED string at 15mA LED current operating in continuous conduction mode using the recommended external components shown in the application circuit on page 1 of this data sheet. As current is further reduced, the regulator enters discontinuous conduction mode. The photo in Figure 1 details circuit operation driving ten LEDs at 10mA load. The inductor current reaches zero during the discharge phase and the SW pin exhibits ringing. The ringing is due to the LC tank circuit formed by the inductor in combination with the switch and diode capacitance. This ringing is not harmful; far less spectral energy is contained in the ringing than in the switch transitions. VSW 20V/DIV IL 20mA/DIV 400ns/DIV VIN = 45V 10 LEDS AT 10mA 3595 F01 Figure 1. Switching Waveforms TYPICAL APPLICATIONS Inductor Selection A 100μH inductor is recommended for most LT3595 applications. Although small size and high efficiency are major concerns, the inductor should have low core losses at 2MHz and low DCR (copper wire resistance). Some inductors that meet these criteria are listed in Table 1. An efficiency comparison of different inductors is shown in Figure 2. 100 COILCRAFT 1812FS-104KLB COILCRAFT LPS4012-104MLB TOKO A915AY-101M TDK VLCF4020T-101MR26 COILTRONICS SD3812-101 COILTRONICS SD52-101 Table 1. Inductor Manufacturers INDUCTANCE RANGE (μH) RELEVANT TO LT3595 100 to 680 100 to 680 100 to 680 100 to 390 100 to 680 100 to 680 100 to 330 VENDOR Coilcraft www.coilcraft.com PART SERIES DO1605 LPS4012 1812FS MSS5131 CDC4D20 D53LC VLCF4020T DIMENSIONS (mm) 5.4 × 4.2 × 1.8 4 × 4 × 1.2 5.8 × 4.9 × 3.8 5.1 × 5.1 × 3.1 4.8 × 4.8 × 2 5.2 × 5.4 × 3 4×4×2 Sumida www.sumida.com Toko www.tokoam.com TDK www.component. tdk.com Coiltronics www.cooperet.com EFFICIENCY (%) 95 SD3812 SD52 LQH32M LQH43M 100 to 330 100 to 330 100 to 560 100 to 680 4 × 4 × 1.2 5.6 × 5.2 × 2 3.2 × 2.5 × 2 4.5 × 3.2 × 2 90 Murata www.murata.com Capacitor Selection 85 0.01 VIN = 45V 10 LEDS 0.1 1 ILED (mA) 10 100 3595 F02 L = 100μH Figure 2. Efficiency Comparison of Different Inductors The small size of ceramic capacitors make them ideal for LT3595 applications. Only X5R and X7R types should be used because they retain their capacitance over wider voltage and temperature ranges than other types such as Y5V or Z5U. Typically, 10μF capacitors on VIN and VCC are sufficient. The output capacitor used across the 3595f 9 LT3595 APPLICATIONS INFORMATION LED string depends on the number of LEDs and can vary from 0.47μF to 1μF. Refer to Table 2 for proper output capacitor selection. Table 2. Recommended Output Capacitor Values (VLED = 3.5V) # LEDs 3-10 1-2 COUT (μF) 0.47 1 Open LED Detection The LT3595 detects an open LED on any channel and reports it to the ⎯O⎯P⎯E⎯N⎯L⎯E⎯D pin. The fault also reports during startup until the output voltage and LED current are in regulation. Therefore, it can also be used as a “power ok” signal. Programming LED Current The set resistor (RSET in the Block Diagram) controls the LED current in all sixteen channels. LED current as a function of the RSET resistance is shown in the Typical Performance Characteristics. Common values for LED current and their required resistor values are listed in Table 4. Since resistor error directly translates to LED current error, precision resistors are preferred (1% is recommended). The maximum allowed resistor value is 150k. Table 4. LED Current vs RSET Resistance RSET (kΩ) 150 75.0 49.9 37.4 30.1 ILED (mA) 10 20 30 40 50 Table 3. Recommended Ceramic Capacitor Manufacturers Taiyo Yuden TDK Murata Kemet (408) 573-4150 www.t-yuden.com (847) 803-6100 www.component.tdk.com (714) 852-2001 www.murata.com (408)-986-0424 www.kemet.com Table 3 shows a list of several ceramic capacitor manufacturers. Consult the manufacturers for detailed information on their entire selection of ceramic parts. 3595f 10 LT3595 APPLICATIONS INFORMATION Dimming Control The sixteen PWM1-16 inputs control the dimming function. Each channel is modulated by its corresponding PWM1-16 input. On a rising edge of any PWM1-16, the IC’s internal support circuitry is enabled and the specific channel turns on. LED current flows in the channel until the falling edge of the PWM1-16 input. In this way, the average LED current is modulated. The minimum on time of a channel is 2μs and the maximum period is 10ms (at 100Hz). Therefore, the maximum dimming ratio is 5000:1. Since the maximum RSET produces 10mA, the minimum modulated LED current is 2μA. When multiple channels are modulated, the rising edges of PWM1-16 must be synchronized. The falling edges may be asynchronous. A sample timing diagram is shown in Figure 3. SYNCHRONIZED RISING EDGES PWM1-4 tON(MIN) = 2μs PWM5-8 tMAX = 10ms PWM9-16 ILED1-4 ILED5-8 ILED9-16 3595 F03 Figure 3. Timing Diagram for Multi-Channel Modulation 3595f 11 LT3595 APPLICATIONS INFORMATION Board Layout Considerations As with all switching regulators, careful attention must be paid to the PCB board layout and component placement. To prevent electromagnetic interference (EMI) problems, proper layout of high frequency switching paths is essential. Minimize the length and area of all traces connected to the SW1-16 and PWM1-16 pins. Keep the sense voltage pins (VIN and L1-16) away from the switching nodes. Place COUT1-16 and CIN close to the VIN pins. Always use a ground plane under the switching regulator to minimize interplane coupling. Recommended component placement is shown in Figures 4-7. Figure 4. PCB Layer 1 Figure 5. PCB Layer 2 3595f 12 LT3595 APPLICATIONS INFORMATION Figure 6. PCB Layer 3 Figure 7. PCB Layer 4 3595f 13 LT3595 TYPICAL APPLICATIONS 30W LED Driver for 160 LEDs (16 Strings, 10 LEDs per String) at 50mA VIN 45V 10μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 100μH 100μH 100μH 100μH 100μH 100μH 100μH VCC 100k LED BRIGHTNESS CONTROL 3V TO 5.5V 10μF L1 SW1 OPENLED PWM1 PWM2 PWM3 PWM4 PWM5 PWM6 PWM7 PWM8 SHDN VCC L16 SW16 L2 SW2 SW3 L3 SW4 L4 L5 SW5 L6 SW6 SW7 L7 100μH SW8 L8 LT3595 L15 100μH 100μH 100μH 100μH 100μH 100μH 100μH 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 100μH 0.47μF 0.47μF 3595 TA02 Conversion Efficiency 100 5000:1 PWM Dimming at 100Hz VPWM 5V/DIV EFFICIENCY (mA) 95 ISW 50mA/DIV 90 ILED 20mA/DIV 400ns/DIV 10 LEDS AT 40mA 3595 TA02c 85 10 20 30 ILED (mA) 40 50 3595 TA02b 30.1k SW15 VIN SW14 L14 SW13 L13 L12 SW12 L11 SW11 VIN SW10 L10 PWM9 PWM10 PWM11 PWM12 PWM13 PWM14 PWM15 PWM16 GND RSET SW9 L9 LED BRIGHTNESS CONTROL 3595f 14 LT3595 PACKAGE DESCRIPTION UHH Package 56-Lead Plastic QFN (5mm × 9mm) (Reference LTC DWG # 05-08-1727 Rev A) 0.70 ± 0.05 5.50 ± 0.05 (2 SIDES) 4.10 ± 0.05 (2 SIDES) 3.60 REF (2 SIDES) 3.45 ±0.05 7.13 ±0.05 PACKAGE OUTLINE 0.20 ± 0.05 0.40 BSC 6.80 REF (2 SIDES) 8.10 ± 0.05 (2 SIDES) 9.50 ± 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 ± 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) 0.75 ± 0.05 0.00 – 0.05 3.60 REF 55 56 0.40 ± 0.10 1 2 PIN 1 NOTCH R = 0.30 TYP OR 0.35 × 45° CHAMFER 9.00 ± 0.10 (2 SIDES) 6.80 REF 7.13 ±0.10 3.45 ±0.10 (UH) QFN 0406 REV A 0.200 REF 0.75 ± 0.05 0.200 REF 0.00 – 0.05 0.20 ± 0.05 0.40 BSC BOTTOM VIEW—EXPOSED PAD R = 0.115 TYP NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 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 0.20mm 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 3595f 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 LT3595 TYPICAL APPLICATIONS 16-Channel LED Driver (Three LEDs per Channel), 20mA Current VIN 15V TO 45V 10μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 5000:1 PWM Dimming at 100Hz VPWM 5V/DIV 100μH 100μH 100μH 100μH 100μH 100μH 100μH 100μH VCC 100k ISW 20mA/DIV L8 ILED 10mA/DIV LED BRIGHTNESS CONTROL 400ns/DIV VIN = 15V 3 LEDS AT 20mA T = 10ms TON = 2μs 3595 TA03b LED BRIGHTNESS CONTROL 3V TO 5.5V 10μF L1 SW1 OPENLED PWM1 PWM2 PWM3 PWM4 PWM5 PWM6 PWM7 PWM8 SHDN VCC L16 SW16 L2 SW2 SW3 L3 SW4 L4 L5 SW5 L6 SW6 SW7 L7 SW8 LT3595 L15 100μH 100μH 100μH 100μH 100μH 100μH 100μH 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 0.47μF 100μH 0.47μF 0.47μF 3595 TA03 RELATED PARTS PART NUMBER LT3463/ LT3463A LT3465/ LT3465A LT3466/ LT3466-1 LT3474 LT3475 LT3476 LT3486 LT3491 LT3497 LT3498 LT3517/LT3518 LT3590 LT3591 DESCRIPTION COMMENTS VIN : 2.3V to 15V, VOUT(MAX) = ±40V, IQ = 40μA, ISD < 1μA, Dual Output, Boost/Inverter, 250mA ISW, Constant Off-Time, High Efficiency Step-Up DC/DC Converter with Integrated Schottky Diodes 3mm × 3mm DFN-10 Package Constant-Current, 1.2MHz/2.7MHz, High Efficiency White LED Boost VIN : 2.7V to 16V, VOUT(MAX) = 34V, IQ = 1.9mA, ISD < 1μA, Regulator with Integrated Schottky Diode ThinSOTTM Package Dual Constant-Current, 2MHz, High Efficiency White LED Boost Regulator with Integrated Schottky Diode 36V, 1A (ILED), 2MHz, Step-Down LED Driver Dual 1.5A (ILED), 36V, 2MHz, Step-Down LED Driver Quad Output 1.5A, 2MHz High Current LED Driver with 1000:1 Dimming Dual 1.3A , 2MHz High Current LED Driver Constant-Current, 2.3MHz, High Efficiency White LED Boost Regulator with Integrated Schottky Diode Dual 2.3MHz, Full Function LED Driver with Integrated Schottky Diodes and 250:1 True Color PWM Dimming VIN : 2.7V to 24V, VOUT(MAX) = 40V, IQ = 5mA, ISD < 16μA, 3mm × 3mm DFN-10 Package VIN : 4V to 36V, VOUT(MAX) = 13.5V, 400:1 True Color PWMTM, ISD < 1μA, TSSOP-16E Package VIN : 4V to 36V, VOUT(MAX) = 13.5V, 3000:1 True Color PWM, ISD < 1μA, TSSOP-20E Package VIN : 2.8V to 16V, VOUT(MAX) = 36V, 1000:1 True Color PWM, ISD < 10μA, 5mm × 7mm QFN-10 Package VIN : 2.5V to 24V, VOUT(MAX) = 36V, 1000:1 True Color PWM, ISD < 1μA, 5mm × 3mm DFN and TSSOP-16E Packages VIN : 2.5V to 12V, VOUT(MAX) = 27V, IQ = 2.6mA, ISD < 8μA, 2mm × 2mm DFN-6 and SC70 Packages VIN : 2.5V to 10V, VOUT(MAX) = 32V, IQ = 6μA, ISD < 12μA, 3mm × 2mm DFN-10 Package 2.3MHz, 20mA LED Driver and OLED Driver with Integrated Schottky VIN : 2.5V to 12V, VOUT(MAX) = 32V, IQ = 1.65mA, ISD < 9μA, Diodes 3mm × 2mm DFN-12 Package 2.3A/1.3A 45V, 2.5MHz Full Featured LED Driver with True Color PWM Dimming 48V Buck Mode LED Driver VIN : 3V to 30V/40V, VOUT(MAX) = 42V, 3000:1 True Color PWM, ISD < 5μA, 4mm × 4mm QFN-16 Package VIN : 4.5V to 55V, VOUT(MAX) = 5V, IQ = 700μA, ISD < 15μA, 2mm × 2mm DFN-16 and SC70 Packages Constant-Current, 1MHz, High Efficiency White LED Boost Regulator VIN : 2.5V to 12V, VOUT(MAX) = 40V, IQ = 4mA, ISD < 9μA, with Integrated Schottky Diode and 80:1 True Color PWM Dimming 3mm × 2mm DFN-8 Package 3595f True Color PWM and ThinSOT are trademarks of Linear Technology Corporation. 75.0k SW15 VIN SW14 L14 SW13 L13 L12 SW12 L11 SW11 VIN SW10 L10 PWM9 PWM10 PWM11 PWM12 PWM13 PWM14 PWM15 PWM16 GND RSET SW9 L9 16 Linear Technology Corporation (408) 432-1900 ● FAX: (408) 434-0507 ● LT 0807 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 www.linear.com © LINEAR TECHNOLOGY CORPORATION 2007