Product Summary

The UC3843B is a high performance current mode PWM controller. 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 UC3843B 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, logic to insure latched operation, the UC3843B also provides current limit control, and a totem pole output stage designed to source or sink high peakcurrent.

Parametrics

UC3843B 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 mJ; (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

UC3843B 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 undervoltage lockout; (7)high current totem pole output; (8)undervoltage lockout with hysteresis; (9)low start-up and operating current.

Diagrams

UC3843B block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
UC3843BD1R2G
UC3843BD1R2G

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM w/96% Duty Cycle Max

Data Sheet

0-1: $0.37
1-25: $0.32
25-100: $0.23
100-500: $0.20
UC3843BVD
UC3843BVD

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable 
UC3843BVD1
UC3843BVD1

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable 
UC3843BVD1R2
UC3843BVD1R2

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable 
UC3843BVDR2
UC3843BVDR2

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable 
UC3843BVN
UC3843BVN

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM

Data Sheet

Negotiable 
UC3843BVDR2G
UC3843BVDR2G

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM w/96% Duty Cycle Max

Data Sheet

0-1620: $0.40
1620-2000: $0.36
2000-2500: $0.36
2500-5000: $0.34
UC3843BVNG
UC3843BVNG

ON Semiconductor

Current Mode PWM Controllers 52kHz 1A Current PWM w/96% Duty Cycle Max

Data Sheet

0-1: $0.71
1-25: $0.59
25-100: $0.51
100-500: $0.43