3517FE

LT3517 LINER

Document overview

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Technical content

FEATURES

APPLICATIONS

DESCRIPTION

with 1.5A Switch Current The L T®3517 is a current mode DC/DC converter with an internal 1.5A, 45V switch specifi cally designed to drive LEDs. The L T3517 operates as a LED driver in boost, buck mode and buck-boost mode. It combines a tradi- tional voltage loop and a unique current loop to operate as a constant-current source or constant-voltage source. Programmable switching frequency allows optimization of the external components for effi ciency or component size. The switching frequency of L T3517 can be synchronized to an external clock signal. The LED current is externally programmable with a 100mV sense resistor . The external PWM input provides up to 5000:1 LED dimming. The CTRL pin provides further 10:1 dimming ratio. The L T3517 is available in the tiny footprint 16-Lead QFN (4mm × 4mm) and the16-Pin TSSOP packages. The L T3517 provides a complete solution for both constant-voltage and constant-current applications. ■ 5000:1 T rue Color PWMTM Dimming Ratio ■ 1.5A, 45V Internal Switch ■ 100mV High Side Current Sense ■ Open LED Protection ■ Adjustable Frequency: 250kHz to 2.5MHz ■ Wide Input Voltage Range: Operation from 3V to 30V T ransient Protection to 40V ■ Operates in Boost, Buck Mode and Buck-Boost Mode ■ Gate Driver for PMOS LED Disconnect* ■ Constant-Current and Constant-Voltage Regulation ■ CTRL Pin Provides 10:1 Analog Dimming ■ Low Shutdown Current: <1μA ■ Available in (4mm × 4mm) 16-Lead QFN and 16-Pin TSSOP Packages ■ Display Backlighting ■ Automotive and Avionic Lighting ■ Illumination ■ Scanners , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. Patent Pending. All other trademarks are the property of their respective owners. *Patents Pendin 10μF 15μH 2.2μF 0.1μF 100mΩ 2.2μF VREF ISP TGEN GNDVREF VC 16.9k 1MHz

3517 TA01a

0.1μF VIN SHDN CTRL PWM SYNC FB SS R T SW PVIN 24V VIN 3.3V ISN L T3517 TG PWM 1A Buck Mode LED Driver Effi ciency PWM DUTY CYCLE (%) EFFICIENCY (%) 100 20 40 60 80

3517 TA01b

CTRL = VREF

V Operating Junction Temperature Range (Notes 2,4) (Note 1) PIN CONFIGURATION ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE L T3517EUF#PBF L T3517EUF#TRPBF 3517 16-Lead (4mm × 4mm) Plastic QFN –40°C to 125°C L T3517IUF#PBF L T3517IUF#TRPBF 3517 16-Lead (4mm × 4mm) Plastic QFN –40°C to 125°C L T3517EFE#PBF L T3517EFE#TRPBF 3517FE 16-Lead Plastic TSSOP –40°C to 125°C L T3517IFE#PBF L T3517IFE#TRPBF 3517FE 16-Lead Plastic TSSOP –40°C to 125°C L T3517HFE#PBF L T3517HFE#TRPBF 3517HFE 16-Lead Plastic TSSOP –40°C to 150°C Consult L TC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container 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/ Storage Temperature Range Lead Temperature (Soldering, 10 sec) 16 15 14 13 5 6 7 8 TOP VIEW UF PACKAGE 16-LEAD (4mm × 4mm) PLASTIC QFN 1 SW SW V IN SHDN FB VC CTRL PWM TG ISP ISN TGEN V REF RT SYNC SS TJMAX = 125°C, θJA = 36°C/W EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB FE PACKAGE 16-LEAD PLASTIC TSSOP TJMAX = 150°C, QJA = 40°C/W , QJC(PAD) = 10°C/W TOP VIEW V IN SHDN VREF RT SYNC SS PWM CTRL SW SW TG ISP ISN TGEN FB V C GND

ELECTRICAL CHARACTERISTICS

PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum VIN Operating Voltage 3V Maximum VIN Operating Voltage Continuous Operation (Note 3) 30 V Current Sense Voltage (VISP – VISN)V CTRL = 2V , VISP = 24V , VC = 1V VCTRL = 2V , VISP = 0V , VC = 1V

• 96 100 100 103 mV mV 10% Scale Current Sense Voltage (VISP – VISN)V CTRL = 100mV , VISP = 24V , VC = 1V 9 mV Current Sense Voltage Line Regulation 2V < V ISP < 45V 0.03 %/V VIN Supply Current PWM > 1.5V , V C = 0V PWM = 0V SHDN = 0V 4.5 0.1 mA mA μA Switching Frequency R T = 16.7k RT = 4.03k RT = 91.5k
• 0.85 2.25 220 1.0 2.5 250 1.15 2.7 270 MHz MHz kHz R T Voltage 1V Soft-Start Pin Current SS = 0.5V , Out of Pin 6 9 12 μA SYNC Pull-Down Current (Into the Pin) V SYNC = 2V 60 μA SYNC Input Low 0.4 V SYNC Input High 1.5 V Maximum Duty Cycle R T = 91.5k (250kHz) SYNC = 300kHz Clock Signal, RT = 91.5k RT = 16.7k (1MHz) RT = 4.03k (2.5MHz) Switch Current Limit 1.5 1.9 2.3 A Switch V CESAT ISW = 1A 300 mV Switch Leakage Current V SW = 45V , PWM = 0V 2 μA CTRL Input Bias Current Current Out of Pin, V CTRL = 0.1V 20 100 nA Error Amplifi er T ransconductance 550 μS VC Output Impedance 1000 kΩ VC Idle Input Bias Current PWM = 0V , V C = 1V –20 0 20 nA FB Pin Input Bias Current Current Out of Pin, V FB = 0.5V 20 100 nA FB Pin Threshold ● 0.98 1.01 1.04 V ISP , ISN Idle Input Bias Current PWM = 0V 300 nA ISP , ISN Full-Scale Input Bias Current ISP Tied to ISN, V ISP = 24V , VCTRL = 2V 20 μA SHDN Voltage High 1.5 V SHDN Voltage Low 0.4 V SHDN Pin Bias Current 60 100 μA PWM Input High Voltage 1.5 V PWM Input Low Voltage 0.4 V PWM Pin Bias Current 60 120 μA The ● denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. (Note 2) VIN = 5V , SHDN = 5V , PWM = 5V unless otherwise noted.

The ● denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. (Note 2) VIN = 5V , SHDN = 5V , PWM = 5V unless otherwise noted. TYPICAL PERFORMANCE CHARACTERISTICS VISP – VISN Threshold vs VCTRL Switch Current Limit vs Duty Cycle Oscillator Frequency vs RT VCTRL (V) VISP – VISN THRESHOLD (mV) 0.4 0.8 1.2 1.6

3518 G01

0.2 0.6 1.0 1.4 VIN = 5V VISP = 24V VC = 1V TA = 25°C RT (kΩ)

100 OSCILLATOR FREQUENCY (kHz)

3518 G03

TA = 25°C DUTY CYCLE (%) SWITCH CURRENT LIMIT (A)0.5 1.0 1.5 2.0 20 40 60 80

3517 G02

TA = 25°C 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 T3517E is guaranteed to meet performance specifi cations from 0°C to 125°C junction temperature. Specifi cations over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The L T3517I is guaranteed over the full –40°C to 125°C operating junction temperature range. The L T3517H is guaranteed over the full –40ºC to 150ºC operating junction temperature range. Operating lifetime is derated at junction temperatures greater than 125ºC. PARAMETER CONDITIONS MIN TYP MAX UNITS TGEN Input High Voltage 1.5 V TGEN Input Low Voltage 0.4 V TGEN Pin Bias Current TGEN = 5V 100 200 μA V REF Pin Voltage I REF = –100μA ● 1.96 2 2.04 V VREF Pin Voltage Line Regulation 3V < V IN < 40V 0.03 %/V Gate Turn-On Delay C LOAD = 1nF Between ISP and TG 200 ns Gate Turn-Off Delay C LOAD = 1nF Between ISP and TG 200 ns Top Gate Drive VGS (VISP – VTG)V ISP = 24V , TGEN = 5V PWM = 0V 0 0.3 V V Note 3: Absolute maximum voltage at VIN, SHDN, PWM and TGEN pins is 40V for nonrepetitive 1 second transients and 30V for continuous operation. Note 4: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed the maximum operating junction temperature when overtemperature protection is active. Continuous operation above the specifi ed maximum operating junction temperature may impair device reliability.

VISP – VISN Threshold vs Temperature Switch Current Limit vs Temperature Oscillator Frequency vs Temperature Reference Voltage vs Temperature Quiescent Current vs VIN TEMPERATURE (°C) –40 VISP – VISN THRESHOLD (mV) 103

3517 G04

–20 0 40 104 102 101 60 80 100 120 140 160 VIN = 5V VISP = 24V VC = 1V VCTRL = 2V TEMPERATURE (°C) –40 –20 1.5 OSCILLATOR FREQUENCY (MHz) 1.9 2.5 0 40 60

3517 G06

1.7 2.3 2.1 20 80 160100 120 140 VIN = 5V RT = 6.04k VISP (V) VISP – VISN THRESHOLD (mV) 101 103 105

3517 G07

VCTRL = 2V VIN = 5V TA = 25°C VC = 1V TEMPERATURE (°C) –40

1.98 VREF (V)

1.99 2.00 2.01 2.02 –20 0 20 40

3517 G08

VIN = 5V VIN (V) VIN CURRENT (mA)

3517 G09

TA = 25°C VC = 0V VISP – VISN Threshold vs VISP TYPICAL PERFORMANCE CHARACTERISTICS FB Pin Threshold vs Temperature PMOS Turn-On PMOS Turn-Off TEMPERATURE (°C) –40

0.98 FB PIN THRESHOLD (V)

1.00 0.99 1.01 1.03 1.02 1.04 –20 0 20 40

3517 G10

VIN = 5V PWM 40V TG 30V 200ns/DIVVISP = 40V

3517 G11

200ns/DIVVISP = 40V TEMPERATURE (°C) –40 –20 SWITCH CURRENT LIMIT (A) 1.0 2.5 0 40 60

3518 G05

0.5 2.0 1.5 20 80 100 120 140 160 VIN = 5V

SW: Switch Pin. Minimize trace at this pin to reduce EMI. VIN: Input Supply Pin. Must be locally bypassed. SHDN: Shutdown Pin. Tie to 1.5V or higher to enable device or 0.4V or less to disable device. VREF: Reference Output Pin. This pin can supply up to 100μA. RT: Switching Frequency Adjustment Pin. Set switching frequency using a resistor to GND (see Typical Performance Characteristics for values). For SYNC function, choose the resistor to program a frequency 20% slower than the SYNC pulse frequency. Do not leave this pin open. SYNC: Frequency Synchronization Pin. Tie an external clock signal here. R T resistor should be chosen to pro- gram a switching frequency 20% slower than SYNC pulse frequency. Synchronization (power switch turn-on) occurs a fi xed delay after the rising edge of SYNC. Tie the SYNC pin to ground if this feature is not used. SS: Soft-Start Pin. Place a soft-start capacitor here. Leave the pin open if not in use. PWM: Pulse Width Modulated Input Pin. Signal low turns off channel, disables the main switch and makes the TG pin high. Tie the PWM pin to V REF pin or SHDN pin if not used. There is an equivalent 50k resistor from PWM pin to ground internally. CTRL: LED Current Adjustment Pin. Sets voltage across sense resistor between ISP and ISN. Connect directly to V REF for full-scale threshold of 100mV , or use signal values between GND and 1V to modulate LED current. Tie the CTRL pin to the V REF pin if not used. VC: gm Error Amplifi er Output Pin. Stabilize the loop with an RC network or compensating C. FB: Voltage Loop Feedback Pin. Works as overvoltage protection for LED drivers. If FB is higher than 1V , the main switch is turned off. TGEN: Top Gate Enable Input Pin. Tie to 1.5V or higher to enable the PMOS driver function. Tie the TGEN pin to ground if TG function is not used. There is an equivalent 40k resistor from TGEN pin to ground internally. ISN: Current Sense (–) Pin. The inverting input to the current sense amplifi er . ISP: Current Sense (+) Pin. The noninverting input to the current sense amplifi er . Also serves as positive rail for TG pin driver . TG: Top Gate Driver Output. An inverted PWM sig- nal drives series PMOS device between V ISP and (VISP – 7V). An internal 7V clamp protects the PMOS gate. Leave TG unconnected if not used. Ground: Exposed Pad. Solder paddle directly to ground plane.

3517 F01

Figure 1. Buck Mode LED Driver

The L T3517 is a constant frequency, current mode regula- tor with an internal power switch. Operation can be best understood by referring to the Block Diagram in Figure 1. At the start of each oscillator cycle, the SR latch is set, which turns on the Q1 power switch. 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 , A4. When this voltage exceeds the level at the negative input of A4, the SR latch is reset, turning off the power switch. The level at the negative input of A4 is set by the error amplifi er A3. A3 has two inputs, one from the voltage feedback loop and the other one from the current loop. Whichever feedback input is lower takes precedence, and forces the converter into either constant-current or constant-voltage mode. The L T3517 is designed to transi- tion cleanly between these two modes of operation. The current sense amplifi er senses the voltage across R SENSE and provides a pre-gain to amplifi er A1. The output of A1 is simply an amplifi ed version of the difference between the voltage across R SENSE and the lower of V CTRL/10 or 100mV . In this manner , the error amplifi er sets the correct peak switch current level to regulate the current through RSENSE. If the error amplifi er’s output increases, more current is delivered to the output; if it decreases, less current is delivered. The current regulated in R SENSE can be adjusted by changing the input voltage V CTRL. The current sense amplifi er provides rail-to-rail current sense operation. The FB voltage loop is implemented by the amplifi er A2. When the voltage loop dominates, the error amplifi er and the amplifi er A2 regulate the FB pin to 1.01V (constant-voltage mode). Dimming of the LED array is accomplished by pulsing the LED current using the PWM pin. When the PWM pin is low, switching is disabled and the error amplifi er is turned off so that it does not drive the V C pin. Also, all internal loads on the VC pin are disabled so that the charge state of the VC pin will be saved on the external compensation capacitor . This feature reduces transient recovery time. When the PWM input again transitions high, the demand current for the switch returns to the value just before PWM last transitioned low. To further reduce transient recovery time, an external PMOS is used to disconnect the LED array current loop when PWM is low, stopping C FIL T from discharging. APPLICATIONS INFORMATION Dimming Control There are two methods to control the current source for dimming using the L T3517. The fi rst method uses the PWM pin to modulate the current source between zero and full current to achieve a precisely programmed aver- age current. To make this method of current control more accurate, the switch demand current is stored on the V C node during the quiescent phase. This feature minimizes recovery time when the PWM signal goes high. To further improve the recovery time, a disconnect switch is used in the LED current path to prevent the output capacitor from discharging in the PWM signal low phase. The minimum PWM on or off time will depend on the choice of operating frequency through R T input pin or SYNC pin. When using the SYNC function, the SYNC and PWM signals must have the aligned rising edges to achieve the optimized high PWM dimming ratio. For best current accuracy, the minimum PWM low or high time should be at least four switching cycles (2μs for f SW = 2MHz). Maximum PWM period is determined by the system and is unlikely to be longer than 12ms. The maximum PWM dimming ratio (PWM RATIO) can be calculated from the maximum PWM period (tMAX) and the minimum PWM pulse width (tMIN) as follows: PWM t tRATIO MAX MIN (1) Example: tMAX = 10ms, tMIN = 2μs (fSW = 2MHz) PWMRATIO = 10ms/2μs = 5000:1 The second method of dimming control uses the CTRL pin to linearly adjust the current sense threshold during the PWM high state. When the CTRL pin voltage is less

than 1V , the LED current is: I V RLED CTRL SENSE = 10  (2) When VCTRL is higher than 1V , the LED current is clamped to be: I mV RLED SENSE = 100 (3) The LED current programming feature possibly increases total dimming range by a factor of ten. The CTRL pin should not be left open (tie to V REF if not used). The CTRL pin can also be used in conjunction with a PTC thermistor to provide overtemperature protection for the LED load. For a buck or a buck-boost confi guration, the output voltage is typically level-shifted to a signal with respect to GND as illustrated in the Figure 4. The output can be expressed as: V R R VVOUT BE Q=+ 1 2 10 1 2. () (5) 49.9k

3517 F02

45.3k 2VVREF PTC CTRL Figure 2 Setting Output Voltage For a boost application, the output voltage can be set by selecting the values of R1 and R2 (see Figure 3) according to the following equation: V R R VOUT =+⎛ 2 11 0 1. (4) L T3517 FB VOUT

3517 F03

3517 F04

The inductor used with the L T3517 should have a satura- tion current rating of 2A or greater . For buck mode LED drivers, the inductor value should be chosen to give a ripple current “ΔI” of ~30% to 40% of the LED current. In the buck mode, the inductor value can be estimated using the formula: Lµ H Dt µ s V V I D V V BUCK SW IN LED BUCK LED () = () ( )  – Δ IIN (6) VLED is the voltage across the LED string, VIN is the input voltage to the converter , and tSW is the switching period. In the boost confi guration, the inductor can be estimated using the formula: Lµ H D t µs V I D VV V BOOST SW IN BOOST LED IN L () = ( )  Δ EED (7)

Table 1 provides some recommended inductor vendors. Table 1. Inductor Manufacturers ceramic capacitor is usually the best choice. capacitor is usually suffi cient. and converter confi guration, i.e., step-up or step-down. sized to attenuate the current ripple. the LED voltage during PWM transitions. to get the required capacitance at the operation voltage. Table 2. Ceramic Capacitor Manufacturers amplifi er whose VC output compensates the control loop. sation resistor and capacitor determine the loop stability.

of LED current during fast transients on VIN or CTRL. recommended component vendors. Table 3. Schottky Diodes

tor values and corresponding switching frequencies. Table 4. Switching Frequency vs RT external clock when external clock is absent.

2000:1 PWM Dimming at 120Hz 350mA, 5V to 12V Boost Converter with Accurate Input Current Limit 10μF 15μH 2.2μF 0.1μF RSENSE 100mΩ M1 2.2μF ISP TGEN GNDVREF VC RT 16.9k 1MHz

3517 TA02a

0.1μF C1: KEMET C0805C225K4RAC C2: MURATA GRM31MR71E225KA93 C3: MURATA GRM32DR71E106KA12B C4, C5: MURATA GRM21BR71H104KA01B D1: DIODES DFLS160 L1: TOKO B992AS-150M LEDS: LUXEON K2 (WHITE) M1: ZETEX ZXMP6A13FTA V IN SHDN CTRL PWM SYNC FB SS R T SW PVIN 24V VIN 3.3V ISN L T3517 TG PWM VREF SW VC GND SS VIN CTRL PWM SHDN TGEN V REF FB VOUT 12V 350mA VIN SYNC 549k 10μF 0.1μFC4 10nF SHDN RT ISN L T3517 TGISP 49.9k RT 6.04k 2MHz 10k

3517 TA03a

2.2μF 6.8μH R SENSE 100mΩ C1: KEMET C0805C225K4RAC C2: KEMET C1206C106K4RAC C3: MURATA GRM21BR71H104KA01B C4: MURATA GCM033R71A103KA03 D1: ZETEX ZLLS1000TA L1: TOKO B992AS-6R8N Effi ciency TYPICAL APPLICATIONS ILOAD(mA) EFFICIENCY (%) 100 150 200 250

3517 TA03b

1μs/DIV PVIN = 24V fOSC = 1MHz ILED = 1A

3517 TA02b

5000:1 PWM Dimming at 100Hz Effi ciency Buck-Boost Mode LED Driver 6.8μH RSENSE 330mΩ SHDN VC GNDRT SS RT 6.04k 2MHz

3517 TA04aC3

0.1μF 4.7μF 3.92M 124k 0.22μF 2.2μF 0.1μF PWM ISP FB ISN TG TGEN VREF CTRL SYNC 300mA VIN 8V TO 16V VIN L T3517 SW PWM C1: KEMET C0806C225K4RAC C2: KEMET C1206C475K3RAC C3, C4: MURATA GRM21BR71H104KA01B C5: MURATA GRM21BR71H224KA01B D1: DIODE DFLS160 L1: TOKO B992AS-6R8N LEDS: LUXEON I (WHITE) M1: ZETEX ZXMP6A13FTA TYPICAL APPLICATIONS PWM DUTY CYCLE (%) EFFICIENCY (%) 20 40 60 80

3517 TA04c

VIN = 12V CTRL = VREF PWM 5V/DIV IL 1A/DIV ILED 200mA/DIV 500ns/DIV VIN = 12V fOSC = 2MHz ILED = 300mA

3517 TA04b

Low Side Current Sensing Load Dump Protected Buck-Boost Mode LED Driver 6.8μH RSENSE 330mΩ SHDN VC GNDRT SS RT 6.04k 2MHz 10k

3517 TA05a

0.1μF 4.7μF 3.92M 124k 0.22μF 2.2μF 33nF PWM ISP FB ISN TG TGEN VREF CTRL SYNC 300mA VIN 8V TO 16V VIN L T3517 SW PWM D1: DIODES DFLS160 L1: TOKO B992AS-6R8N C1: KEMET C0806C225K4RAC C2: KEMET C1206C475K3RAC C3: MURATA GRM21BR71H104KA01B C4: MURATA GRM219R71H333KAQ01B C5: MURATA GRM21BR71H224KA01B M1: ZETEX ZXMP6A13FTA LEDs: LUXEON I (WHITE) TYPICAL APPLICATIONS 5000:1 PWM Dimming at 100Hz Effi ciency PWM 5V/DIV IL 1A/DIV ILED 200mA/DIV 500ns/DIV VIN = 12V fOSC = 2MHz ILED = 300mA

3517 TA05b

PWM DUTY CYCLE (%) EFFICIENCY (%) 20 40 60 80

3517 TA05c

VIN = 12V CTRL = VREF VISP REF GND 5ms/DIV VIN Raises From 15V to 40V in 5ms.

3517 TA05d

Boost 100mA LED Driver with LED Open Protection LED1 LED2 LED10 22μH RSENSE 30.1k SHDN VC GNDRT SS RT 16.9k 1MHz

3517 TA06a

0.1μF 2.2μF 2.2μF 0.1μF PWM ISP ISN TG FB TGEN VREF CTRL SYNC 100mA VIN 8V TO 16V VIN L T3517 SW PWM C1, C2: KEMET C1206C225K2RAC C3, C4: MURATA GRM21BR71H104KA01B D1: DIODES DFLS160 L1: COILCRAFT DS3316P-223 LEDS: CREE XLAMP 7090 M1: ZETEX ZXMP6A13FTA 3000:1 PWM Dimming at 100Hz Effi ciency PWM DUTY CYCLE (%) EFFICIENCY (%) 20 40 60 80

3517 TA06c

VIN = 12V CTRL = VREF PWM 5V/DIV IL 500mA/DIV ILED 100mA/DIV 1μs/DIV VIN = 12V fOSC = 1MHz ILED = 100mA

3517 TA06b

5.5V SEPIC Converter with Short-Circuit Protection SW VC GND SS CTRL SYNC SHDN TGEN V REF FB TG ISP ISN RT VOUT 5.5V 350mA VIN 221k 10μF 10μF 0.1μFC4 10nF SHDN PWM L T3517 VIN 49.9k RT 6.04k 2MHz 10k

3517 TA07a

2.2μF 4.3μH 4.3μH R SENSE 0.22Ω C1: KEMET C0805C225K4RAC C2, C5: KEMET C1206C106K4RAC C3: MURATA GRM21BR71H104KA01B C4: MURATA GCM033R71A103KA03 D1: ZETEX ZLLS1000TA L1, L2: TOKO B992AS-4R3N Effi ciency TYPICAL APPLICATION ILOAD (mA) EFFICIENCY (%) 50 100 150 200

3517 TA07b

16-Lead Plastic QFN (4mm × 4mm) (Reference L TC DWG # 05-08-1692) 4.00 p 0.10 (4 SIDES) NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (W 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUD E MOLD FLASH. MOLD FLASH, IF PRESENT , SHALL NOT EXCEED 0.15mm ON A 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONL Y A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE PIN 1 TOP MARK (NOTE 6) 0.55 p 0.20 1615 BOTTOM VIEW—EXPOSED PAD 2.15 p 0.10 (4-SIDES) 0.75 p 0.05 R = 0.115 TYP 0.30 p 0.05

0.65 BSC

0.200 REF

0.00 – 0.05 (UF16) QFN 1004 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 0.72 p0.05 0.30 p0.05 2.15 p 0.05 (4 SIDES)2.90 p 0.05 4.35 p 0.05 PACKAGE OUTLINE PIN 1 NOTCH R = 0.20 TYP OR 0.35 s 45o CHAMFER

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. 16-Lead Plastic TSSOP (4.4mm) (Reference L TC DWG # 05-08-1663) Exposed Pad Variation BA FE16 (BA) TSSOP 0204 0.09 – 0.20 (.0035 – .0079) 0° – 8° 0.25 REF 0.50 – 0.75 (.020 – .030) 4.30 – 4.50* (.169 – .177) 13 4 5 6 7 8 10 9 4.90 – 5.10* (.193 – .201) 16 1514 13 12 11 1.10 (.0433) MAX 0.05 – 0.15 (.002 – .006) 0.65 (.0256) BSC 2.74 (.108) 2.74 (.108) 0.195 – 0.30 (.0077 – .0118) TYP MILLIMETERS (INCHES) *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006") PER SIDE NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE IN RECOMMENDED SOLDER PAD LAYOUT 3. DRAWING NOT TO SCALE 0.45 p0.05 4.50 p0.10 6.60 p0.10 1.05 p0.10 2.74 (.108) 2.74 (.108) SEE NOTE 4 4. RECOMMENDED MINIMUM PCB METAL SIZE FOR EXPOSED PAD ATTACHMENT 6.40 (.252) BSC PACKAGE DESCRIPTION

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 0308 REV A • PRINTED IN USA RELATED PARTS PART NUMBER DESCRIPTION COMMENTS L T1618 Constant Current, 1.4MHz, 1.5A Boost Converter V IN: 5V to 18V , VOUT(MAX) = 36V , Dimming = Analog/PWM, ISD < 1μA, L T3003 3-Channel LED Ballaster with PWM Dimming V IN: 3V to 48V , Dimming = 3,000:1 T rue Color PWM, ISD < 5μA, L T3474 36V , 1A (I LED), 2MHz, Step-Down LED Driver V IN: 4V to 36V , VOUT(MAX) = 13.5V , Dimming = 400:1 T rue Color PWM, ISD < 1μA, TSSOP16E Package L T3475 Dual 1.5A (I LED), 36V 2MHz Step-Down LED Driver V IN: 4V to 36V , VOUT(MAX) = 13.5V , Dimming = 3,000:1 T rue Color PWM, ISD < 1μA, TSSOP20E Package L T3476 Quad Output 1.5A, 36V , 2MHz High Current LED Driver with 1,000:1 Dimming VIN: 2.8V to 16V , VOUT(MAX) = 36V , Dimming = 1,000:1 T rue Color PWM, ISD < 10μA, 5mm × 7mm QFN Package L T3477 3A, 42V , 3MHz Boost, Buck-Boost, Buck LED Driver V IN: 2.5V to 25V , VOUT(MAX) = 40V , Dimming = Analog/PWM, ISD < 1μA, QFN, TSSOP20E Packages L T3478/L T3478-1 4.5A, 42V , 2.5MHz High Current LED Driver with 3,000:1 Dimming VIN: 2.8V to 36V , VOUT(MAX) = 42V , Dimming = 3,000:1 T rue Color PWM, ISD < 3μA, TSSOP16E Packages L T3479 3A, Full Featured DC/DC Converter with Soft-Start and Inrush Current Protection VIN: 2.5V to 24V , VOUT(MAX) = 40V , IQ = 6.5mA, ISD < 1μA, DFN and TSSOP Packages L T3486 Dual 1.3A, 2MHz High Current LED Driver V IN: 2.5V to 24V , VOUT(MAX) = 36V , Dimming = 1,000:1 T rue Color PWM, ISD < 1μA, 5mm × 3mm DFN, TSSOP16E L T3496 T riple Output LED Driver V IN: 3V to 40V , VOUT(MAX) = 45V , Dimming = 3,000:1 T rue Color PWM, ISD < 10μA, 4mm × 5mm QFN Package L T3518 Full-Featured LED Driver with 2.3A Switch Current V IN: 3V to 40V , VOUT(MAX) = 45V , Dimming = 3,000:1 T rue Color PWM, ISD < 10μA, 4mm × 4mm QFN Package L T3590 48V Buck Mode 50mA LED Driver V IN: 4.5V to 55V , Drives Up to 10 LEDs, 200:1 Dimming, ISO = 15mA, 2mm × 2mm DFN SC70 L T3595 16 Channel Buck LED Driver Mode V IN: 4.5V to 45V , Drives Up to 160 LEDs, 5,000:1 Dimming, 5mm × 9mm QFN LT C®3783 High Current LED Controller V IN: 3V to 36V , VOUT(MAX) = Ext FET , Dimming = 3,000:1 T rue Color PWM, ISD < 20μA, 5mm × 4mm QFN10, TSSOP16E Packages