Product Summary

The UC3843BD is a high performance fixed frequency current mode controller. It is designed for Off Line and DC.DC converter applications offering the designer a cost effective solution with minimal external components. The UC3843BD features a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. The UC3843BD is available in an 8.pin dual in line and surface mount (SOIC.8) plastic package as well as the 14.pin plastic surface mount (SOIC.14). The SOIC.14 package has separate power and ground pins for the totem pole output stage.

Parametrics

UC3843BD absolute maximum ratings: (1)Bias and Driver Voltages (Zero Series Impedance, see also Total Device spec): 30V; (2)Total Power Supply and Zener Current: 30mA; (3)Output Current, Source or Sink: 1.0A; (4)Output Energy (Capacitive Load per Cycle): 5.0μJ; (5)Current Sense and Voltage Feedback Inputs: -0.3V to + 5.5V; (6)Error Amp Output Sink Current: 10mA; (7)Power Dissipation and Thermal Characteristics: 702mW, 178℃/W; (8)Operating Junction Temperature: +150℃; (9)Operating Ambient Temperature: -40℃ to 105℃; (10)Storage Temperature Range: -65℃ to +150℃.

Features

UC3843BD features: (1)Trimmed Oscillator for Precise Frequency Control; (2)Oscillator Frequency Guaranteed at 250 kHz; (3)Current Mode Operation to 500 kHz; (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 Startup and Operating Current; (10)Pb-Free Packages are Available.

Diagrams

UC3843BD block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
UC3843BD
UC3843BD
ON Semiconductor
Current Mode PWM Controllers 52kHz 1A Current PWM
Data Sheet
Negotiable 
UC3843BD1
UC3843BD1
STMicroelectronics
Current Mode PWM Controllers 0.5mA Current Mode
Data Sheet
0-1: $0.38
1-10: $0.35
10-100: $0.29
100-250: $0.25
UC3843BD1013TR
UC3843BD1013TR
STMicroelectronics
Current Mode PWM Controllers 0.5mA Current Mode
Data Sheet
0-1: $0.34
1-10: $0.30
10-100: $0.26
100-250: $0.24
UC3843BD1G
UC3843BD1G
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
UC3843BD1R2
UC3843BD1R2
ON Semiconductor
Current Mode PWM Controllers 52kHz 1A Current PWM
Data Sheet
Negotiable 
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
UC3843BDG
UC3843BDG
ON Semiconductor
Current Mode PWM Controllers ANA SMPS PWM CNTRL
Data Sheet
0-1: $0.37
1-25: $0.32
25-100: $0.23
100-500: $0.20
UC3843BDR2
UC3843BDR2
ON Semiconductor
Current Mode PWM Controllers 52kHz 1A Current PWM
Data Sheet
Negotiable