(China (Mainland))
Product Summary
The UC3844B is a control IC. It 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 of the UC3844B include a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lock-out featuring start-up current less than 0.5mA, a precision reference trimmed for accuracy at the error amp input, logicto insure latched operation, a PWM comparator which also provides current limit control, and a totempole output stage designed to source or sink high peak current. The UC3844B output stage, suitable for driving N-Channel MOSFETs, is low in the off-state.
Parametrics
UC3844B absolute maximum ratings: (1)Vi, Supply Voltage (low impedance source): 30 V; (2)IO, Output Current ±1 A; (3)EO, Output Energy (capacitive load): 5 μJ; (4)Analog Inputs (pins 2, 3): – 0.3 to 5.5 V; (5)Error Amplifier Output Sink Current: 10 mA; (6)Ptot, Power Dissipation at Tamb ≤ 25℃ (Minidip): 1.25 W; (7)Ptot, Power Dissipation at Tamb ≤ 25℃ (SO8): 800 mW; (8)Tstg, Storage Temperature Range: – 65 to 150℃; (9)TJ, Junction Operating Temperature: – 40 to 150℃; (10)TL, Lead Temperature (soldering 10s): 300℃.
Features
UC3844B features: (1)trimmed oscillator for precise frequency control; (2)oscillator frequency guaranteed at 250kHz; (3)current mode operation to 500kHz; (4)automatic feed forward compensation; (5)latching PWM for cycle-by-cycle current limiting; (6)internally trimmed reference with under voltage lockout; (7)high current totem pole output; (8)undervoltage lockout with hysteresis; (9)low start-up and operating current.
Diagrams
| Image | Part No | Mfg | Description |  |
Pricing (USD) |
Quantity | ||||||||||||
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 UC3844B |
Other |
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Data Sheet |
Negotiable |
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UC3844BD |
ON Semiconductor |
Current Mode PWM Controllers 52kHz 1A Current PWM |
Data Sheet |
Negotiable |
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UC3844BD1 |
STMicroelectronics |
Current Mode PWM Controllers PWM CONTROLLER |
Data Sheet |
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UC3844BD1013TR |
STMicroelectronics |
Current Mode PWM Controllers 0.5mA Current Mode |
Data Sheet |
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UC3844BD1G |
ON Semiconductor |
Current Mode PWM Controllers 52kHz 1A Current PWM w/48% Duty Cycle Max |
Data Sheet |
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UC3844BD1R2 |
ON Semiconductor |
Current Mode PWM Controllers 52kHz 1A Current PWM |
Data Sheet |
Negotiable |
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UC3844BD1R2G |
ON Semiconductor |
Current Mode PWM Controllers 52kHz 1A Current PWM w/48% Duty Cycle Max |
Data Sheet |
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UC3844BDG |
ON Semiconductor |
Current Mode PWM Controllers ANA SMPS PWM CNTRL |
Data Sheet |
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