LT3002IS8E#PBF

LT3002 36V 10W No-Opto Isolated Flyback Converter FEATURES DESCRIPTION 4V to 36V Input Voltage Range nn 3.6A, 65V Internal DMOS Power Switch nn Low Quiescent Current nn Quasi-Resonant Boundary Mode Operation at Heavy Load nn Low Ripple Burst Mode® Operation at Light Load nn Minimum Load < 0.5% (Typ) of Full Output nn No Transformer Third Winding or Opto-Isolator Required for Output Voltage Regulation nn Accurate EN/UVLO Threshold and Hysteresis nn Temperature Compensation for Output Diode nn Output Short-Circuit Protection nn Thermally Enhanced 8-Lead SO Package The LT®3002 is a monolithic micropower isolated flyback converter. By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no third winding or opto-isolator for regulation. The output voltage is programmed with two external resistors and a third optional temperature compensation resistor. Boundary mode operation provides a small magnetic solution with excellent load regulation. Low ripple Burst Mode operation maintains high efficiency at light load while minimizing the output voltage ripple. A 3.6A, 65V DMOS power switch is integrated along with all the high voltage circuitry and control logic into a thermally enhanced 8-lead SO package. nn APPLICATIONS Isolated Automotive, Industrial, Medical Power Supplies nn Isolated Auxiliary/Housekeeping Power Supplies nn The LT3002 operates from an input voltage range of 4V to 36V and delivers up to 10W of isolated output power. The high level of integration and the use of boundary and low ripple burst modes result in a simple to use, low component count, and high efficiency application solution for isolated power delivery. All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents, including 5438499, 7463497, 7471522. TYPICAL APPLICATION 4V to 32VIN/5VOUT Isolated Flyback Converter 3:1 470pF 10µF 39Ω VIN SW EN/UVLO LT3002 GND 1µF INTVCC 9µH • • 1µH VOUT– 10mA TO 1.1A (VIN = 5V) 10mA TO 2.0A (VIN = 12V) 10mA TO 2.9A (VIN = 24V) RREF 115k TC 85 220µF 154k RFB 90 VOUT+ 5V 10k EFFICIENCY (%) VIN 4V TO 32V Efficiency vs Load Current 80 75 70 VIN = 5V VIN = 12V VIN = 24V 65 3002 TA01a 60 0 0.5 2.0 1.5 1.0 LOAD CURRENT (A) 2.5 3.0 3002 TA01b Rev. 0 Document Feedback For more information www.analog.com 1 LT3002 ABSOLUTE MAXIMUM RATINGS (Note 1) PIN CONFIGURATION SW (Note 2)...............................................................65V VIN.............................................................................42V EN/UVLO.....................................................................VIN RFB.........................................................VIN – 0.5V to VIN Current Into RFB.....................................................200µA INTVCC, RREF, TC..........................................................4V Operating Junction Temperature Range (Notes 3, 4) LT3002E, LT3002I.............................. –40°C to 125°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec).................... 300°C TOP VIEW EN/UVLO 1 8 TC INTVCC 2 7 RREF 6 RFB 5 SW VIN 3 GND 4 9 GND S8E PACKAGE 8-LEAD PLASTIC SO θJA = 33°C/W EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3002ES8E#PBF LT3002ES8E#TRPBF 3002 8-Lead Plastic SO –40°C to 125°C LT3002IS8E#PBF LT3002IS8E#TRPBF 3002 8-Lead Plastic SO –40°C to 125°C Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. 2 Rev. 0 For more information www.analog.com LT3002 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 5V, VEN/UVLO = VIN, CINTVCC = 1µF to GND, unless otherwise noted. SYMBOL PARAMETER VIN VIN Voltage Range CONDITIONS IQ VIN Quiescent Current VEN/UVLO = 0.2V Active Mode EN/UVLO Shutdown Threshold For Lowest Off IQ EN/UVLO Enable Threshold Falling MIN TYP 4 0.5 380 0.2 0.75 1.178 1.214 EN/UVLO Enable Hysteresis MAX UNIT 36 V 2 µA µA V 1.250 14 V mV IHYS EN/UVLO Hysteresis Current VEN/UVLO = 1.1V VEN/UVLO = 1.3V 2.3 –0.1 2.5 0 2.7 0.1 µA µA VINTVCC INTVCC Regulation Voltage IINTVCC = 0mA to 10mA 2.85 3 3.1 V IINTVCC INTVCC Current Limit VINTVCC = 2.8V mA INTVCC UVLO Threshold Falling 10 13 20 2.39 2.47 2.55 INTVCC UVLO Hysteresis (RFB – VIN) Voltage 105 IRFB = 75µA to 125µA –50 RREF Regulation Voltage l 0.98 mV 50 1.00 V mV 1.02 V 15 –200 18 µA µA 12 12.7 kHz VTC TC Pin Voltage ITC TC Pin Current 1.00 fMIN Minimum Switching Frequency tON(MIN) Minimum Switch-On Time ISW(MAX) Maximum Switch Current Limit 3.6 4.5 5.4 A ISW(MIN) Minimum Switch Current Limit 0.70 0.87 1.04 A RDS(ON) Switch On-Resistance VTC = 1.2V VTC = 0.8V 12 11.3 V 160 ISW = 1.5A 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 SW pin is rated to 65V for transients. Depending on the leakage inductance voltage spike, operating waveforms of the SW pin should be derated to keep the flyback voltage spike below 65V. Note 3: The LT3002E is guaranteed to meet performance specifications from 0°C to 125°C junction temperature. Specifications over the –40°C 80 ns mΩ to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LT3002I is guaranteed over the full –40°C to 125°C operating junction temperature range. Note 4: The LT3002 includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 150°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Rev. 0 For more information www.analog.com 3 LT3002 TYPICAL PERFORMANCE CHARACTERISTICS Output Load and Line Regulation 5.3 5.2 5.05 5.00 4.95 VIN = 5V VIN = 12V VIN = 24V 4.80 0 0.5 1.0 2.0 1.5 LOAD CURRENT (A) 2.5 RTC = 115k 5.0 RTC = OPEN 4.9 4.7 –50 –25 0 VSW 20V/DIV VOUT 50mV/DIV VOUT 50mV/DIV 3002 G04 VIN = 5V VIN = 12V VIN = 24V 0 2.0 1.0 1.5 LOAD CURRENT (A) 0.5 EN/UVLO Enable Threshold 1.010 2.5 3.0 3002 G03 Burst Mode Waveforms VSW 20V/DIV VOUT 50mV/DIV 2µs/DIV FRONT PAGE APPLICATION VIN = 12V IOUT = 0.5A 1.240 3002 G05 20µs/DIV FRONT PAGE APPLICATION VIN = 12V IOUT = 10mA RREF Regulation Voltage 3002 G06 Switch Current Limit 5 1.008 1.235 RISING 1.006 1.230 4 MAXIMUM CURRENT LIMIT 1.004 1.220 FALLING 1.215 1.002 ISW (A) 1.225 VRREF (V) VEN/UVLO (V) 0 25 50 75 100 125 150 TEMPERATURE (°C) Discontinuous Mode Waveforms VSW 20V/DIV 1.000 0.998 3 2 0.996 1.210 0.994 1.205 1 MINIMUM CURRENT LIMIT 0.992 0 25 50 75 100 125 150 TEMPERATURE (°C) 0.990 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 3002 G07 4 200 3002 G02 Boundary Mode Waveforms 1.200 –50 –25 300 100 4.8 3.0 FRONT PAGE APPLICATION 400 5.1 3002 G01 2µs/DIV FRONT PAGE APPLICATION VIN = 12V IOUT = 2A 500 FRONT PAGE APPLICATION VIN = 12V IOUT = 1A FREQUENCY (kHz) 5.10 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 5.15 4.85 Switching Frequency vs Load Current Output Temperature Variation 5.20 4.90 TA = 25°C, unless otherwise noted. 3002 G08 0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 3002 G09 Rev. 0 For more information www.analog.com LT3002 PIN FUNCTIONS EN/UVLO (Pin 1): Enable/Undervoltage Lockout. The EN/UVLO pin is used to enable the LT3002. Pull the pin below 0.3V to shut down the LT3002. This pin has an accurate 1.214V threshold and can be used to program a VIN undervoltage lockout (UVLO) threshold using a resistor divider from VIN to ground. A 2.5µA current hysteresis allows the programming of VIN UVLO hysteresis. If neither function is used, tie this pin directly to VIN. INTVCC (Pin 2): Internal 3V Linear Regulator Output. The INTVCC pin is supplied from VIN and powers the internal control circuitry and gate driver. Do not overdrive the INTVCC pin with any external supply, such as a third winding supply. Locally bypass this pin to ground with a minimum 1µF ceramic capacitor. VIN (Pin 3): Input Supply. The VIN pin supplies current to the internal circuitry and serves as a reference voltage for the feedback circuitry connected to the RFB pin. Locally bypass this pin to ground with a capacitor. GND (Pin 4, Exposed Pad Pin 9): Ground. The exposed pad provides both electrical contact to ground and good thermal contact to the printed circuit board. Solder the exposed pad directly to the ground plane. SW (Pin 5): Drain of the Internal DMOS Power Switch. Minimize trace area at this pin to reduce EMI and voltage spikes. RFB (Pin 6): Input Pin for External Feedback Resistor. Connect a resistor from this pin to the transformer primary SW pin. The ratio of the RFB resistor to the RREF resistor, times the internal voltage reference, determines the output voltage (plus the effect of any non-unity transformer turns ratio). Minimize trace area at this pin. RREF (Pin 7): Input Pin for External Ground Referred Reference Resistor. The resistor at this pin should be in the range of 10k, but for convenience in selecting a resistor divider ratio, the value may range from 9.09k to 11.0k. TC (Pin 8): Output Voltage Temperature Compensation. The voltage at this pin is proportional to absolute temperature (PTAT) with temperature coefficient equal to 3.35mV/°K, i.e., equal to 1V at room temperature 25°C. The TC pin voltage can be used to estimate the LT3002 junction temperature. Connect a resistor from this pin to the RREF pin to compensate the output diode temperature coefficient. OPERATION The LT3002 is a current mode switching regulator IC designed specially for the isolated flyback topology. The key problem in isolated topologies is how to communicate the output voltage information from the isolated secondary side of the transformer to the primary side for regulation. Historically, opto-isolators or extra transformer windings communicate this information across the isolation boundary. Opto-isolator circuits waste output power, and the extra components increase the cost and physical size of the power supply. Opto-isolators can also cause system issues due to limited dynamic response, nonlinearity, unit-to-unit variation and aging over lifetime. Circuits employing extra transformer windings also exhibit deficiencies, as using an extra winding adds to the transformer’s physical size and cost, and dynamic response is often mediocre. The LT3002 samples the isolated output voltage through the primary-side flyback pulse waveform. In this manner, neither opto-isolator nor extra transformer winding is required for regulation. Since the LT3002 operates in either boundary conduction mode or discontinuous conduction mode, the output voltage is always sampled on the SW pin when the secondary current is zero. This method improves load regulation without the need of external load compensation components. Rev. 0 For more information www.analog.com 5 LT3002 APPLICATIONS INFORMATION Output Voltage tOFF(MIN) = Minimum switch-off time = 350ns (TYP) The RFB and RREF resistors are external resistors used to program the output voltage. ISW(MIN) = Minimum switch current limit = 0.87A (TYP) The output voltage is set by: ⎛ R ⎞ ⎛ 1 ⎞ VOUT = VREF • ⎜ FB ⎟ • ⎜ – VF ⎝ RREF ⎠ ⎝ NPS ⎟⎠ VF = Output diode forward voltage NPS = Transformer effective primary-to-secondary turns ratio VREF = Internal reference voltage 1.00V Output Temperature Compensation To cancel the output diode temperature coefficient, the following two equations should be satisfied: VOUT = VREF • ( VTC / T) • RFB 1 • – VF (T0 ) RREF NPS ( VTC / T ) = 3.35mV/ °C The LT3002 obtains output voltage information from the reflected output voltage on the SW pin. The conduction of secondary current reflects the output voltage on the primary SW pin. The sample-and-hold error amplifier needs a minimum 350ns to settle and sample the reflected output voltage. In order to ensure proper sampling, the secondary winding needs to conduct current for a minimum of 350ns. The following equation gives the minimum value for primary-side magnetizing inductance: 6 tOFF(MIN) •NPS • ( VOUT + VF ) ISW(MIN) ISW(MIN) Undervoltage Lockout (UVLO) Primary Inductance Requirement LPRI ≥ tON(MIN) • VIN(MAX) In general, choose a transformer with its primary magnetizing inductance about 40% to 60% larger than the minimum values calculated above. A transformer with much larger inductance will have a bigger physical size and may cause instability at light load. T0 =Room temperature 25°C VF / T ) = Output diode forward voltage temperature coefficient LPRI ≥ tON(MIN) = Minimum switch-on time = 160ns (TYP) RFB 1 • = – ( VF / T ) R TC NPS ( In addition to the primary inductance requirement for the minimum switch-off time, the LT3002 has minimum switch-on time that prevents the chip from turning on the power switch shorter than approximately 160ns. This minimum switch-on time is mainly for leading-edge blanking the initial switch turn-on current spike. If the inductor current exceeds the desired current limit during that time, oscillation may occur at the output as the current control loop will lose its ability to regulate. Therefore, the following equation relating to maximum input voltage must also be followed in selecting primary-side magnetizing inductance: A resistive divider from VIN to the EN/UVLO pin implements undervoltage lockout (UVLO). The EN/UVLO enable falling threshold is set at 1.214V with 14mV hysteresis. In addition, the EN/UVLO pin sinks 2.5µA when the voltage on the pin is below 1.214V. This current provides user programmable hysteresis based on the value of R1. The programmable UVLO thresholds are: 1.228V • (R1+R2) + 2.5µA •R1 R2 1.214V • (R1+R2) VIN(UVLO– ) = R2 VIN(UVLO+ ) = Figure 1 shows the implementation of external shutdown control while still using the UVLO function. The NMOS grounds the EN/UVLO pin when turned on, and puts the LT3002 in shutdown with quiescent current less than 2µA. Rev. 0 For more information www.analog.com LT3002 APPLICATIONS INFORMATION Step 1: Select the transformer turns ratio. VIN R1 R2 LT3002 GND Minimum Load Requirement The LT3002 samples the isolated output voltage from the primary-side flyback pulse waveform. The flyback pulse occurs once the primary switch turns off and the secondary winding conducts current. In order to sample the output voltage, the LT3002 has to turn on and off for a minimum amount of time and with a minimum frequency. The LT3002 delivers a minimum amount of energy even during light load conditions to ensure accurate output voltage information. The minimum energy delivery creates a minimum load requirement, which can be approximately estimated as: ILOAD(MIN) = LPRI •ISW(MIN)2 • fMIN 2 • VOUT VOUT + VF Example: 3002 F01 Figure 1. Undervoltage Lockout (UVLO) 65V – VIN(MAX) – VLEAKAGE VLEAKAGE = Margin for transformer leakage spike = 15V VF = Output diode forward voltage = ~0.3V EN/UVLO RUN/STOP CONTROL (OPTIONAL) NPS < NPS < 65V – 32V – 15V = 3.4 5V + 0.3V The choice of transformer turns ratio is critical in determining output current capability of the converter. Table 1 shows the switch voltage stress and output current capability at different transformer turns ratio. Table 1. Switch Voltage Stress and Output Current Capability vs Turns Ratio NPS VSW(MAX) at VIN(MAX) (V) IOUT(MAX) at VIN(MIN) (A) DUTY CYCLE (%) 1:1 37.3 0.92 14-40 2:1 42.6 1.31 25-57 3:1 47.9 1.53 33-67 Clearly, only NPS = 3 can meet the 1.5A output current requirement, so NPS = 3 is chosen as the turns ratio in this example. Step 2: Determine the primary inductance. LPRI = Transformer primary inductance ISW(MIN) = Minimum switch current limit = 1.04A (MAX) fMIN = Minimum switching frequency = 12.7kHz (MAX) The LT3002 typically needs less than 0.5% of its full output power as minimum load. Alternatively, a Zener diode with its breakdown of 10% higher than the output voltage can serve as a minimum load if pre-loading is not acceptable. For a 5V output, use a 5.6V Zener with cathode connected to the output. Design Example Use the following design example as a guide to designing applications for the LT3002. The design example involves designing a 5V output with a 1.5A load current and an input range from 8V to 32V. Primary inductance for the transformer must be set above a minimum value to satisfy the minimum switch-off and switch-on time requirements: LPRI ≥ LPRI ≥ tOFF(MIN) • NPS • ( VOUT + VF ) ISW(MIN) tON(MIN) • VIN(MAX) ISW(MIN) tOFF(MIN) = 350ns tON(MIN) = 160ns ISW(MIN) = 0.87A VIN(MIN) = 8V, VIN(NOM) = 12V, VIN(MAX) = 32V, VOUT = 5V, IOUT = 1.5A For more information www.analog.com Rev. 0 7 LT3002 APPLICATIONS INFORMATION Example: needs to conduct much higher current. Therefore, a conservative metric is 60% of the maximum switch current limit multiplied by the turns ratio: 350ns • 3 • ( 5V + 0.3V ) = 6.4µH 0.87A 160ns • 32V = 5.9µH LPRI ≥ 0.87A LPRI ≥ IDIODE(MAX) = 0.6 • ISW(MAX) • NPS Example: Most transformers specify primary inductance with a tolerance of ±20%. With other component tolerance considered, choose a transformer with its primary inductance 40% to 60% larger than the minimum values calculated above. LPRI = 9µH is then chosen in this example. IDIODE(MAX) = 8.1A Once the primary inductance has been determined, the maximum load switching frequency can be calculated as: 1 1 fSW = = LPRI •ISW tON + tOFF LPRI •ISW + VIN NPS • ( VOUT + VF ) ISW = VOUT •IOUT • 2 η • VIN • D VREVERSE = VOUT + VIN(MAX) NPS Example: VREVERSE = 5V + 32V = 15.7V 3 The PDS835L (8A, 35V diode) from Diodes Inc. is chosen. Step 4: Choose the output capacitor. The output capacitor should be chosen to minimize the output voltage ripple while considering the increase in size and cost of a larger capacitor. Use the following equation to calculate the output capacitance: Example: D= Next calculate reverse voltage requirement using maximum VIN: (5V + 0.3V ) • 3 = 0.57 (5V + 0.3V ) • 3 + 12V 5V • 1.5A • 2 ISW = 0.8 • 12V • 0.57 fSW = 277kHz COUT = LPRI •ISW2 2 • VOUT • ΔVOUT Example: The transformer also needs to be rated for the correct saturation current level across line and load conditions. A saturation current rating larger than 7A is necessary to work with the LT3002. Design for output voltage ripple less than ±1% of VOUT, i.e., 100mV. Step 3: Choose the output diode. Two main criteria for choosing the output diode include forward current rating and reverse-voltage rating. The maximum load requirement is a good first-order guess at the average current requirement for the output diode. Under output short-circuit condition, the output diode 8 COUT 2 9µH • ( 4.5A ) = = 182µF 2 • 5V • 0.1V Remember ceramic capacitors lose capacitance with applied voltage. The capacitance can drop to 40% of quoted capacitance at the maximum voltage rating. So a 220µF, 6.3V rating X5R or X7R ceramic capacitor is chosen. Rev. 0 For more information www.analog.com LT3002 APPLICATIONS INFORMATION Step 5: Design snubber circuit. Step 7: Adjust RFB resistor based on output voltage. The snubber circuit protects the power switch from leakage inductance voltage spike. A (RC + DZ) snubber is recommended for this application. A 470pF capacitor in series with a 39Ω resistor is chosen as the RC snubber. Build and power up the application with application components and measure the regulated output voltage. Adjust RFB resistor based on the measured output voltage: The maximum Zener breakdown voltage is set according to the maximum VIN: VZENNER(MAX) ≤ 60V – VIN(MAX) A 24V Zener with a maximum of 26V will provide optimal protection and minimize power loss. So a 24V, 1.5W Zener from Central Semiconductor (CMZ5934B) is chosen. VOUT VOUT(MEASURED) • RFB Example: Example: VZENNER(MAX) ≤ 60V – 32V = 28V RFB(NEW) = RFB = 5V • 158k = 154k 5.14V Step 8: Select RTC resistor based on output voltage temperature variation. VREVERSE > VSW(MAX) Measure output voltage in a controlled temperature environment like an oven to determine the output temperature coefficient. Measure output voltage at a consistent load current and input voltage, across the operating temperature range. VSW(MAX) = VIN(MAX) + VZENNER(MAX) Calculate the temperature coefficient of VF: Choose a diode that is fast and has sufficient reverse voltage breakdown: Example: VOUT ( T1) – VOUT ( T2) T1– T2 3.35mV/°C ⎛ RFB ⎞ RTC = • – ( δVF /δT ) ⎜⎝ NPS ⎟⎠ – ( δVF /δT ) = VREVERSE > 60V A 100V, 1A diode from Diodes Inc. (DFLS1100) is chosen. Step 6: Select the RREF and RFB resistors. Use the following equation to calculate the starting values for RREF and RFB: Example: RFB = ( – ( δVF /δT ) = ) RREF • NPS • VOUT + VF ( T0 ) VREF RTC = 5.189V – 5.041V = 1.48mV / °C 100°C – ( 0°C) 3.35mV/°C ⎛ 154 ⎞ •⎜ ⎟ = 115k 1.48mV/°C ⎝ 3 ⎠ RREF = 10k Example: Step 9: Select the EN/UVLO resistors. RFB = Determine the amount of hysteresis required and calculate R1 resistor value: 10k • 3 • ( 5V + 0.3V ) = 159k 1.00V For 1% standard values, a 158k resistor is chosen. VIN(HYS) = 2.5µA • R1 Example: Choose 2V of hysteresis, R1 = 806k Rev. 0 For more information www.analog.com 9 LT3002 APPLICATIONS INFORMATION Determine the UVLO thresholds and calculate R2 resistor value: 1.228V • (R1+ R2) VIN(UVLO+) = + 2.5µA • R1 R2 Step 10: Ensure minimum load. The theoretical minimum load can be approximately estimated as: ILOAD(MIN) = 2 9µH • ( 1.04A ) • 12.7kHz =12.4mA 2 • 5V Example: Set VIN UVLO rising threshold to 7.5V: Remember to check the minimum load requirement in real application. The minimum load occurs at the point where the output voltage begins to climb up as the converter delivers more energy than what is consumed at the output. The real minimum load for this application is about 10mA. In this example, a 500Ω resistor is selected as the minimum load. R2 = 232k VIN(UVLO+) = 7.5V VIN(UNLO–) = 5.5V 10 Rev. 0 For more information www.analog.com LT3002 PACKAGE DESCRIPTION S8E Package 8-Lead Plastic SOIC (Narrow .150 Inch) Exposed Pad (Reference LTC DWG # 05-08-1857 Rev C) .050 (1.27) BSC .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 (1.143 ±0.127) 8 .089 .160 ±.005 (2.26) (4.06 ±0.127) REF .245 (6.22) MIN .150 – .157 .080 – .099 (2.032 – 2.530) (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) 1 .030 ±.005 (0.76 ±0.127) TYP .005 (0.13) MAX 7 5 6 .118 (2.99) REF 3 2 .118 – .139 (2.997 – 3.550) 4 RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN .014 – .019 (0.355 – 0.483) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010" (0.254mm) 4. STANDARD LEAD STANDOFF IS 4mils TO 10mils (DATE CODE BEFORE 542) 5. LOWER LEAD STANDOFF IS 0mils TO 5mils (DATE CODE AFTER 542) 4 5 .004 – .010 0.0 – 0.005 (0.101 – 0.254) (0.0 – 0.130) .050 (1.270) BSC S8E 1015 REV C Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license For is granted implication or otherwise under any patent or patent rights of Analog Devices. more by information www.analog.com 11 LT3002 12 Rev. 0 08/19 www.analog.com For more information www.analog.com  ANALOG DEVICES, INC. 2019