LT3436 LINER [Linear Technology], LT3436 Datasheet
LT3436
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LT3436 Summary of contents
Page 1
... Full cycle-by-cycle switch current limit protection and ther- mal shutdown are provided. High frequency operation al- lows the reduction of input and output filtering components and permits the use of tiny chip inductors. The LT3436 is available in an exposed pad, 16-pin TSSOP package. , LTC and LT are registered trademarks of Linear Technology Corporation. ...
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... Switch Voltage ......................................................... 35V SHDN Pin ............................................................... 25V FB Pin Current ....................................................... 1mA SYNC Pin Current .................................................. 1mA Operating Junction Temperature Range (Note 2) LT3436E .......................................... – 40°C to 125°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C ELECTRICAL CHARACTERISTICS range, otherwise specifications are at T ...
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... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT3436E is guaranteed to meet performance specifications from 0°C to 125°C. Specifications over the – 40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls ...
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... LT3436 W U TYPICAL PERFOR A CE CHARACTERISTICS SHDN Supply Current 300 T = 25° 15V IN 250 200 150 100 0.2 0.4 0.6 0.8 1.0 1.2 1.4 SHDN VOLTAGE (V) 3436 G07 PIN FUNCTIONS GND (Pins 16, 17): Short GND pins and the exposed pad (pin 17) on the PCB. The GND is the reference for the regulated output, so load regulation will suffer if the “ ...
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... W BLOCK DIAGRAM The LT3436 is a constant frequency, current-mode boost converter. This means that there is an internal clock and two feedback loops that control the duty cycle of the power switch. In addition to the normal error amplifier, there is a current sense amplifier that monitors switch current on a cycle-by-cycle basis ...
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... Y5V or similar type ceramics can be used since the absolute value of capacitance is less important and has no significant effect on loop stability. If operation is required close to the minimum input voltage required by either the output or the LT3436, a larger value may be necessary. loop compen- C This is to prevent excessive ripple causing dips below the minimum operating voltage resulting in erratic operation. Ω ...
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... INDUCTOR CHOICE AND MAXIMUM OUTPUT CURRENT When choosing an inductor, there are 2 conditions that limit the minimum inductance; required output current, and avoidance of subharmonic oscillation. The maximum output current for the LT3436 in a standard boost con- verter configuration with an infinitely large inductor is: η V • ...
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... SHUTDOWN AND UNDERVOLTAGE LOCKOUT Figure 4 shows how to add undervoltage lockout (UVLO) to the LT3436. Typically, UVLO is used in situations where the input supply is current limited , or has a relatively high source resistance. A switching regulator draws constant power from the source, so source current increases as source voltage drops ...
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... Board layout also has a significant effect on thermal resistance. The exposed pad is the copper plate that runs under the LT3436 die. This is the best thermal path for heat out of the package. Soldering the pad onto the board will reduce die temperature and increase the power capability of the LT3436 ...
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... MAXIMUM OUTPUT CURRENT IS SUBJECT TO THERMAL DERATING. D1 MINIMIZE LT3436, C1, D1 LOOP V OUT KELVIN SENSE V OUT Figure 6. Typical Application and Suggested Layout (Topside Only Shown 3.9µH D1 B220A OPEN LT3436 OR HIGH SHDN SYNC GND C C2 10nF C4 R3 470pF 4.7k INPUT GND C1 PLACE FEEDTHROUGHS ...
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... Inductor resistance contributes directly to the efficiency losses in the overall converter. THERMAL CALCULATIONS Power dissipation in the LT3436 chip comes from four sources: switch DC loss, switch AC loss, drive current, and input quiescent current. The following formulas show how to calculate each of these losses. These formulas assume continuous mode operation, so they should not be used for calculating efficiency at light load currents ...
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... V (V) IN 3436 TA02c OUT 12V Q1 0.8A C7 22µF R1 90.9k R2 10k 1% LT3436 • TA02 D1 B220A V OUT OPT OPT 31. 22µF CDRH6D28-100 X5R R2 10V CERAMIC 10K 1% GND 3436 TA02b Efficiency 12V IN 3. ...
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... C OUT GND GND Q1 78.7k 0.1µF 8.2k 4.99k D1 B220A † V OUT 5V R2 31.6k 1% • L1B* 47µF 15µH 10V R3 10k 1% LT3436 • TA03 OUT LXHL-PW09 EMITTER LED OUT 49.9Ω LT1783 – Q2 22µF X5R 10V 1.21k CERAMIC 1% 3436 TA03b LT3436 ...
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... SHDN LT3436 R5 SYNC V C 23.7k GND GND 124k 0.1µF R6 8.2k 4.99k V OUT 5V R1 31. 47µF 10V R2 10k 1% LT3436 • TA04 D1 B130A V OUT 700mA LT1783 – C2 22µF V OUT R4 R2 X5R 1k 0.068Ω 16V 1% 1% CERAMIC 3436 TA04b 3436fa ...
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... BSC 4. RECOMMENDED MINIMUM PCB METAL SIZE FOR EXPOSED PAD ATTACHMENT MILLIMETERS (INCHES) *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006") PER SIDE LT3436 4.90 – 5.10* (.193 – .201) 3.58 (.141) 16 1514 6.40 2.94 (.252) ( ...
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... SD www.linear.com ● 47k 5W LASER L1 = TBD 190Ω Q1 ZETEX ZTX849 1% 0.47µF = WIMA 3X 0.15µF TYPE MKP-20 HV DIODES = SEMTECH-FM-50 LASER = HUGHES 3121H-P COILTRONICS (407) 241-7876 LT3436 • TA05 = 35V 12mA, OUT(MAX 35V/42V 4.5mA, OUT(MAX 35V/42V 4mA, OUT(MAX 0.9V to 10V 34V 3mA, IN OUT(MAX 1.6V to 18V 35V ...