Product Summary

The UC3844N is a control IC. The UC3844N 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 1mA, 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 UC3844N, suitable for driving N Channel MOSFETs, is low in the off state.

Parametrics

UC3844N absolute maximum ratings: (1)Supply Voltage (Low Impedance Source):30V; (2)Supply Voltage (ICC < 30mA): Self Limiting; (3)Output Current:±1A; (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 at TA ≤ 25℃ (DIL8): 1 W; (8)Power Dissipation at TA ≤ 25℃ (SOIC-14): 725 mW; (9)Storage Temperature Range: -65 to +150℃; (10)Junction Temperature Range: -55 to +150℃; (11)Lead Temperature (soldering, 10 seconds): 300℃.

Features

UC3844N features: (1)Optimized For Off-line And DC To DC Converters; (2)Low Start Up Current (<1mA); (3)utomatic 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)500khz Operation; (11)Low RO Error Amp.

Diagrams

UC3844N block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
UC3844N
UC3844N

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
UC3844NG
UC3844NG

ON Semiconductor

Other Power Management 52kHz 1A Current PWM w/48% Duty Cycle Max

Data Sheet

Negotiable 
UC3844NG4
UC3844NG4

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