LT1952EGN-1PBF LINER [Linear Technology], LT1952EGN-1PBF Datasheet
LT1952EGN-1PBF
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LT1952EGN-1PBF Summary of contents
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FEATURES n Synchronous Rectifi er Control for High Effi ciency n Programmable Volt-Second Clamp n Output Power Levels from 25W to 500W n Low Current Start-Up (LT1952: 460μA; V On/Off = 14.25V/8.75V) IN (LT1952-1: 400μA; V On/Off = 7.75V/6.5V) IN ...
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... LT1952IGN#TRPBF LT1952EGN-1#PBF LT1952EGN-1#TRPBF LT1952IGN-1#PBF LT1952IGN-1#TRPBF LEAD BASED FINISH TAPE AND REEL LT1952EGN LT1952EGN#TR LT1952IGN LT1952IGN#TR LT1952EGN-1 LT1952EGN-1#TR LT1952IGN-1 LT1952IGN-1#TR Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. For more information on lead free part marking, go to: For more information on tape and reel specifi ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are 0.1μF , SD_V = 2V, BLANK = 121k, DELAY = 121k, I SEC PARAMETER V (LT1952 (LT1952) IN OFF V (LT1952) IN HYSTERESIS V (LT1952-1) IN ...
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... Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LT1952EGN/LT1952EGN-1 are 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 ...
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TYPICAL PERFORMANCE CHARACTERISTICS FB Voltage vs Temperature 1.25 1.24 1.23 1.22 1.21 1.20 –50 – 100 TEMPERATURE (°C) 1952 G01 V Start-up Current IN vs Temperature 600 SD_V = 1.4V SEC 550 500 LT1952 450 400 ...
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LT1952/LT1952-1 TYPICAL PERFORMANCE CHARACTERISTICS COMP Source Current vs Temperature 12 COMP = 1.6V 10.0 7.5 CURRENT OUT OF PIN 5.0 –50 – 100 TEMPERATURE (°C) 1952 G10 I Maximum Threshold SENSE vs COMP ...
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TYPICAL PERFORMANCE CHARACTERISTICS BLANK Duration vs R BLANK 1000 T = 25°C A 800 600 400 200 100 120 140 R (k) BLANK 1952 G26 OUT Rise/Fall Time vs OUT Load Capacitance 125 T ...
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LT1952/LT1952-1 PIN FUNCTIONS COMP (Pin 1): Output Pin of the Error Amplifi er. The error amplifi amp, allowing various compensation networks to be connected between the COMP pin and FB pin for optimum transient response. The ...
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TIMING DIAGRAM SOUT OUT SS_MAXDC FAULTS TRIGGERING SOFT-START V < 8.75V IN OR SD_V < 1.32V (UVLO) SEC OR OC > 107mV (OVERCURRENT) BLOCK DIAGRAM START-UP LT1952 V ON INPUT CURRENT (ISTART OFF I = ...
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LT1952/LT1952-1 OPERATION Introduction The LT1952/LT1952-1 are current mode synchronous PWM controllers optimized for control of the simplest forward converter topology—using only one primary MOSFET. The LT1952/LT1952-1 are ideal for 25W to 500W power systems where very high effi ciency and ...
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OPERATION catastrophic damage. Many converters solve this problem by limiting the operational duty cycle of the MOSFET to 50% or less—or by using a fi xed (non-adaptive) maximum duty cycle clamp with very large voltage rated MOSFETs. The LT1952/LT1952-1 provide ...
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LT1952/LT1952-1 OPERATION Slope Compensation The current mode architecture requires slope compensa- tion to be added to the current sensing loop to prevent subharmonic oscillations which can occur for duty cycles above 50%. Unlike most current mode converters which have a ...
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APPLICATIONS INFORMATION current (460μA LT1952; 400μA LT1952-1) allows a large resistor to be connected between system input supply and V . Once the part is turned on, input current increases to IN drive the IC (4.5mA) and the output drivers ...
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LT1952/LT1952-1 APPLICATIONS INFORMATION Blanking is provided in 2 phases (Figure 6): The fi rst phase automatically blanks during gate rise time. Gate rise times can vary depending on MOSFET type. For this reason the LT1952/LT1952-1 perform true ‘leading edge blanking’ ...
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APPLICATIONS INFORMATION Programming Synchronous Rectifi er Timing: SOUT to OUT delay (‘t ’) DELAY The LT1952/LT1952-1 have an additional output SOUT which provides a ±50mA peak drive clamped to 12V. In applications requiring synchronous rectifi cation for high effi ciency, ...
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LT1952/LT1952-1 APPLICATIONS INFORMATION Example calculation for (2) For R = 35.7k 100k REF R = 40k 200kHz and SD_V DELAY OSC this gives SS_MAXDC(DC) = 1.84V, t and Maximum Duty ...
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APPLICATIONS INFORMATION (A) V > 14.25* (7.75V LT1952-1), and IN (B) SD_V > 1.32V, and SEC (C) OC < 107mV, and (D) SS_MAXDC < 0.45V (SS_MAXDC reset threshold) *V > 8.75V (6.5V LT1952- for latch reset if the ...
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LT1952/LT1952-1 APPLICATIONS INFORMATION V (t) = SS_MAXDC(DC) (1 – give • (–1) • ln(1 – V /SS_MAXDC(DC)) SS where SS_MAXDC voltage at time t SS SS_MAXDC(DC) = programmed DC voltage setting maximum ...
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APPLICATIONS INFORMATION For SD_V = 1.32V, fOSC = 200kHz and R SEC This gives and t = 40ns. DELAY Re-arranging the above equation to solve for SS_MAXDC = V SS(REG • f )(SD_V ...
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LT1952/LT1952-1 APPLICATIONS INFORMATION LOAD CURRENT (A) Figure 12. LT1952-Based Synchronous Forward Converter Effi ciency vs Load Current (For Circuit in Figure 14) 16 SOUT SOUT SD_V SEC 5 SS_MAXDC ...
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APPLICATIONS INFORMATION 48V to Isolated 12V, 20A (No Opto-Coupler) ‘Bus Converter’ The wide programmable range and accuracy of the LT1952/LT1952-1 Volt-Second clamp makes the LT1952/ LT1952-1 an ideal choice for ‘Bus Converter’ applications where the Volt-Second clamp provides line regulation ...
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LT1952/LT1952-1 APPLICATIONS INFORMATION 36V to 72V Input, 3.3V 40A Converter An LT1952-based synchronous forward converter provides the ideal solution for power supplies requiring high effi ciency at low output voltages and high load currents. The 3.3V 40A solution in Figure ...
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APPLICATIONS INFORMATION Bus Converter: Optimum Output Voltage Tolerance The Bus Converter applications shown on page 1 and in Figure 16, provide semi-regulated isolated outputs without the need for an optocoupler, optocoupler driver, reference or feedback network. The LT1952/LT1952-1Volt-Second clamp adjusts ...
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LT1952/LT1952-1 PACKAGE DESCRIPTION .254 MIN .0165 .0015 RECOMMENDED SOLDER PAD LAYOUT .007 – .0098 (0.178 – 0.249) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE * ...