Product Summary

The UC3843D is a current mode PWM controller. The UC3843D of control devices 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 under-voltage lockout featuring start up current less than 1 mA, 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, suitable for driving N-Channel MOSFETs, is low in the off state.

Parametrics

UC3843D absolute maximum ratings: (1)Supply voltage(Low impedance source): 30V; (2)Supply voltage(ICC<30 mA): self limiting; (3)Output current: ±1 A; (4)Output energy (capacitive load): 5 μJ; (5)Analog inputs (Pins 2, 3): –0.3V to 6.3V; (6)Error amp output sink current: 10 mA; (7)Power dissipation(TA≤25℃): 725mW; (8)Storage temperature range: –65℃ to 15℃; (9)Junction temperature range: –55℃ to 150℃; (10)Lead temperature (soldering, 10 seconds): 300℃.

Features

UC3843D features: (1)Optimized For Off-line and DC-to-DC Converters; (2)Low Start-Up Current (<1 mA); (3)Automatic Feed Forward Compensation; (4) Pulse-by-Pulse Current Limiting; (5) Enhanced Load Response Characteristics; (6) Under-Voltage Lockout With Hysteresis; (7) Double Pulse Suppression; (8) High Current Totem Pole Output; (9) Internally Trimmed Bandgap Reference; (10)500-kHz Operation; (11) Low RO Error Amp.

Diagrams

UC3843D block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
UC3843D
UC3843D

Texas Instruments

Current Mode PWM Controllers Current Mode

Data Sheet

0-1: $0.85
1-25: $0.76
25-100: $0.67
100-250: $0.59
UC3843D1
UC3843D1

Fairchild Semiconductor

Current Mode PWM Controllers Current Mode PWM Control IC

Data Sheet

Negotiable 
UC3843D1X
UC3843D1X

Fairchild Semiconductor

Current Mode PWM Controllers Current Mode PWM Control IC

Data Sheet

Negotiable 
UC3843D8
UC3843D8

Texas Instruments

Current Mode PWM Controllers Current Mode

Data Sheet

0-1: $0.85
1-25: $0.76
25-100: $0.67
100-250: $0.59
UC3843D8G4
UC3843D8G4

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1: $0.85
1-25: $0.76
25-100: $0.67
100-250: $0.59
UC3843D8TR
UC3843D8TR

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1730: $0.33
1730-2000: $0.31
2000-2500: $0.31
2500-5000: $0.30
UC3843D8TRG4
UC3843D8TRG4

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1730: $0.33
1730-2000: $0.31
2000-2500: $0.31
2500-5000: $0.30
UC3843DTR
UC3843DTR

Texas Instruments

Current Mode PWM Controllers Current-Mode PWM Controller

Data Sheet

0-1730: $0.33
1730-2000: $0.31
2000-2500: $0.31
2500-5000: $0.30