Product Summary
The UC3843 is a high performance current mode PWM controller. The UC3843 provides the necessary features to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lockout featuring start-up current less than 0.5mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage of the UC3843 suitable for driving N-Channel MOSFETs, is low in the off-state.
Parametrics
UC3843 absolute maximum ratings: (1)Vi Supply Voltage (low impedance source): 30 V; (2)Vi Supply Voltage (Ii <30mA): Self Limiting; (3)IO Output Current: ±1 A; (4)EO Output Energy (capacitive load): 5 μJ; (5)Analog Inputs (pins 2, 3) – 0.3 to 5.5 V; (6)Error Amplifier Output Sink Current: 10 mA; (7)Ptot Power Dissipation at Tamb ≤ 25℃ (DIP-8): 1.25 W; (8)Ptot Power Dissipation at Tamb ≤ 25℃ (SO-8): 800 mW; (9)Tstg Storage Temperature Range: – 65 to 150℃; (10)TJ Junction Operating Temperature: – 40 to 150℃; (11)TL Lead Temperature (soldering 10s): 300℃.
Features
UC3843 features: (1)trimmed oscillator discharge current; (2)current mode operation to 500khz automatic feed forward; (3)compensation; (4)latching pwm for cycle-by-cycle current limiting; (5)internally trimmed reference with undervoltage lockout; (6)high current totem pole output undervoltage lockout with; (7)hysteresis; (8)low start-up current (<0.5mA) double pulse suppression.
Diagrams

| Image | Part No | Mfg | Description | ![]() |
Pricing (USD) |
Quantity | ||||
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![]() UC3843 |
![]() Other |
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![]() Data Sheet |
![]() Negotiable |
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![]() UC3843A |
![]() Other |
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![]() Data Sheet |
![]() Negotiable |
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![]() UC3843AD1 |
![]() ON Semiconductor |
![]() Other Power Management 52kHz 1A Current PWM |
![]() Data Sheet |
![]() Negotiable |
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![]() |
![]() UC3843AD1013TR |
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![]() IC REG CTRLR BST FLYBK ISO 8SOIC |
![]() Data Sheet |
![]() Negotiable |
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![]() |
![]() UC3843AD1G |
![]() ON Semiconductor |
![]() Other Power Management 52kHz 1A Current PWM w/96% Duty Cycle Max |
![]() Data Sheet |
![]() Negotiable |
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![]() |
![]() UC3843AD1R2 |
![]() ON Semiconductor |
![]() Other Power Management 52kHz 1A Current PWM |
![]() Data Sheet |
![]() Negotiable |
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![]() |
![]() UC3843AD1R2G |
![]() ON Semiconductor |
![]() Other Power Management 52kHz 1A Current PWM w/96% Duty Cycle Max |
![]() Data Sheet |
![]() Negotiable |
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![]() |
![]() UC3843AD2R2 |
![]() ON Semiconductor |
![]() Other Power Management 52kHz 1A Current PWM |
![]() Data Sheet |
![]() Negotiable |
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(Hong Kong)










