UC3843 Current-Mode PWM Controller IC DIP-8

Description

UC3843 Current-Mode PWM Controller IC DIP-8 The UC3843 Current-Mode PWM Controller IC DIP-8 is a high-performance, fixed-frequency PWM controller designed for efficient DC-DC and off-line converter applications. It integrates key control features including a precision 5V reference, oscillator, error amplifier, current-sense comparator, and a high-current totem-pole output stage capable of directly driving power MOSFETs. Operating from a wide supply voltage range of 7.6V to 30V, the UC3843 provides excellent line and load regulation with current-mode operation for fast transient response and cycle-by-cycle current limiting. Its high oscillator frequency up to 500kHz allows for compact power supply designs. Encased in a standard 8-pin DIP package, it is widely used in switch-mode power supplies (SMPS), DC-DC converters, battery chargers, and motor control circuits for its reliability, efficiency, and precise performance. Features Wide operating voltage range from 7.6V to 30V. Fixed-frequency current-mode PWM control for fast transient response. High oscillator frequency operation up to 500kHz. Totem-pole output stage capable of ±1A peak current to drive MOSFETs directly. Low start-up current (<1mA) for energy-efficient power-up. Accurate 5V ±1% reference voltage for stable system operation. Cycle-by-cycle current limiting for enhanced protection. Undervoltage lockout (UVLO) with hysteresis for reliable startup and shutdown. Automatic feed-forward compensation and double-pulse suppression. Compact 8-pin DIP package suitable for SMPS, DC-DC converters, and motor control circuits. Pinout Configuration Pin No. Symbol Name / Function 1 COMP Compensation input – error amplifier output used for loop compensation 2 VFB Feedback input – voltage feedback to the internal error amplifier 3 ISENSE Current sense input – monitors switch current for current-mode control and protection 4 RT/CT Oscillator timing resistor/capacitor – sets the switching frequency 5 GND Ground reference for all signals 6 OUTPUT Output drive pin – to drive an external MOSFET or transistor 7 VCC Supply voltage input (operating range: 7.6 V – 30 V) 8 VREF 5 V reference output (can source up to 20 mA for biasing) Dimensions Specifications Parameter Descriptions Product Type Current-Mode PWM / DC-DC Converter Control IC Part Number UC3843AN Datasheet UC3843 Package Type DIP-8 Operating Voltage Range 7.6 V – 30 V Reference Voltage 5.0 V ±2% Oscillation Frequency 500 kHz Output Type Adjustable Topology Supported Buck, Boost, Flyback, Forward Number of Channels 1 Switch Type External MOSFET required Undervoltage Lockout (UVLO) 7.6 V (start) – 6.9 V (stop) Output Drive Capability ±1 A peak Optimization General-purpose PWM control, suitable for wide duty cycle designs Maximum Duty Cycle 100% UVLO Thresholds (Start/Stop) Slightly higher thresholds Design Flexibility Allows full-range duty cycles for continuous conduction designs Control Method Fixed-frequency peak current-mode PWM Main Application Forward converters, continuous-mode flyback converters Operating Temperature Range 0 °C – +70 °C Applications Switch-Mode Power Supplies (SMPS). DC-DC Converter Circuits. Battery Chargers and Power Adapters. LED Drivers and Lighting Power Supplies. Motor Speed Control Systems. Inverter and Converter Modules. Industrial and Consumer Power Electronics. Offline Flyback and Forward Converter Designs. Package Contents 1 x UC3843 Current-Mode PWM Controller IC DIP-8 Datasheet UC3843

From the supplier's page.