UC3844BD1 STMicroelectronics, UC3844BD1 Datasheet
UC3844BD1
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UC3844BD1 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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... V 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 UC2842BD1; UC3842BD1 UC2843BD1; UC3843BD1 UC2844BD1; UC3844BD1 UC2845BD1; UC3845BD1 2/15 Parameter 25 C (Minidip) amb 25 C (SO8) Minidip/SO8 COMP ...
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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 -25 < T < for UC284XB; 0 < T amb Symbol Parameter REFERENCE SECTION V Output Voltage ...
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UC2842B/3B/4B/5B - UC3842B/3B/4B/5B 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 Threshold Min Operating Voltage ...
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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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UC2842B/3B/4B/5B - UC3842B/3B/4B/5B Figure 4: Oscillator Discharge Current vs. Tem- perature. I dischg (mA 8.5 8.0 7.5 7.0 -55 - Figure 6: Error Amp Open-Loop Gain and Phase vs. Frequency. (dB) V =15V i V ...
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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˚ Sink Saturation (Load ...
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UC2842B/3B/4B/5B - UC3842B/3B/4B/5B Figure 15 : Error Amp Configuration Figure 16 : Under Voltage Lockout. 7 ON/OFF COMMAND OFF Figure 17 : Current Sense Circuit . CURRENT ...
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Figure 18 : Slope Compensation Techniques. V REG SLOPE SENSE R S Figure 19 : Isolated MOSFET Drive and Current Transformer Sensing ...
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UC2842B/3B/4B/5B - UC3842B/3B/4B/5B 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 SCR as shown. All ...
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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 of C Figure 23: External Duty Cycle Clamp and Multi Unit Synchronization. V ...
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UC2842B/3B/4B/5B - UC3842B/3B/4B/5B Figure 24: Soft-Start Circuit Figure 25: Soft-Start and Error Amplifier Output Duty Cycle Clamp BC109 V CLAMP 12/15 R BIAS R ...
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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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UC2842B/3B/4B/5B - UC3842B/3B/4B/5B mm DIM. MIN. TYP. MAX. 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 e4 7.62 F 6.6 I ...
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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 ...