uc3842td STMicroelectronics, uc3842td Datasheet
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uc3842td
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uc3842td Summary of contents
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HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER . TRIMMED OSCILLATOR FOR PRECISE FRE- . QUENCY CONTROL OSCILLATOR FREQUENCY GUARANTEED . AT 250kHz . CURRENT MODE OPERATION TO 500kHz AUTOMATIC FEED FORWARD COMPENSA- . TION LATCHING PWM FOR CYCLE-BY-CYCLE . CURRENT ...
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... This output directly drives the gate of a power MOSFET. Peak currents are sourced and sunk by this pin This pin is the positive supply of the control IC This is the reference output. It provides charging current for capacitor C ref ORDERING NUMBERS SO8 UC3842TD UC3843TD UC3844TD UC3845TD 2/15 Parameter 25 C (Minidip) amb 25 C (SO8) Minidip/SO8 1 8 ...
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THERMAL DATA Symbol R Thermal Resistance Junction-ambient. th j-amb ELECTRICAL CHARACTERISTICS ( [note 1] Unless otherwise stated, these specifications apply for 0 < T < 105° 15V (note 5); R amb i Symbol Parameter REFERENCE SECTION Line Regulation ...
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UC3842T - UC3843T - UC3844T - UC3845T ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter OUTPUT SECTION V Output Low Level OL V Output High Level OH V UVLO Saturation OLS t Rise Time r t Fall Time f UNDER-VOLTAGE LOCKOUT SECTION Start ...
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Figure 1: Open Loop Test Circuit. 4.7K 2N2222 100K ERROR AMP. ADJUST 1K I 4.7K SENSE ADJUST 5K D95IN343 High peak currents associated with capacitive loads necessitate careful grounding techniques. Timing and bypass capacitors should be connected close Figure 2: ...
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UC3842T - UC3843T - UC3844T - UC3845T Figure 4: Oscillator Discharge Current vs. Tem- perature. I dischg (mA) V =15V i V OSC 8.5 8.0 7.5 7.0 -55 - Figure 6: Error Amp Open-Loop Gain and ...
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Figure 10: Output Saturation Voltagevs. Load Current. V sat (V) Source Saturation V i (Load to Ground =25˚ =15V Pulsed Load 120Hz Rate 3 T =-40˚ ...
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UC3842T - UC3843T - UC3844T - UC3845T Figure 15 : Error Amp Configuration Figure 16 : Under Voltage Lockout. 7 ON/OFF COMMAND V TO REST OFF Figure 17 : Current Sense Circuit ...
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Figure 18 : Slope Compensation Techniques. V REG SLOPE SENSE Figure 19 : Isolated MOSFET Drive and Current Transformer Sensing. V ...
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UC3842T - UC3843T - UC3844T - UC3845T Figure 20 : Latched Shutdown. 2N 3905 SCR must be selected for a holding current of less than 0.5mA at T The simple two transistor circuit can be used in place of the ...
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Figure 22: External Clock Synchronization. EXTERNAL SYNC INPUT 0.01 F The diode clamp is required if the Sync amplitude is large enough to cause the bottom side more than 300mV below ground T Figure 23: External ...
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UC3842T - UC3843T - UC3844T - UC3845T Figure 24: Soft-Start Circuit Figure 25: Soft-Start and Error Amplifier Output Duty Cycle Clamp BC109 C ...
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DIM. MIN. TYP. MAX. MIN. A 1.75 a1 0.1 0.25 0.004 a2 1.65 a3 0.65 0.85 0.026 b 0.35 0.48 0.014 b1 0.19 0.25 0.007 C 0.25 0.5 0.010 c1 45 (typ.) D (1) 4.8 5.0 0.189 E 5.8 ...
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UC3842T - UC3843T - UC3844T - UC3845T mm DIM. MIN. TYP. MAX. MIN. A 3.32 a1 0.51 0.020 B 1.15 1.65 0.045 b 0.356 0.55 0.014 b1 0.204 0.304 0.008 D 10.92 E 7.95 9.75 0.313 e 2.54 e3 7.62 ...
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... No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMi- croelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics ...