UC3842DTR

Power Supply Controllers, Monitors Overview

The UC3842DTR is a current-mode PWM controller manufactured by Texas Instruments, designed for offline and DC-to-DC converter applications. It operates within an input supply voltage range of 12 V to 28 V with a typical operating supply current of 25 mA. The device features undervoltage lockout (UVLO) thresholds of 16 V and 10 V, ensuring stable startup and shutdown behavior. It supports switching frequencies up to 500 kHz and includes automatic feedforward compensation. The component is available in a 14-pin SOIC (D) package and functions as a single-ended controller optimized for high-performance power supply designs.

Power Supply Controllers, Monitors Feature Summary

• Current-mode PWM control architecture for precise regulation
• Integrated undervoltage lockout with hysteresis for reliable startup
• Automatic feedforward compensation for improved line regulation
• Optimized design for offline and DC-to-DC converter topologies

Power Supply Controllers, Monitors Applications

• Offline flyback converters
• Forward converters
• Push-pull converters
• Half-bridge and full-bridge DC-to-DC converters

Power Supply Controllers, Monitors Procurement Notes

Verify the suffix 'DTR' indicates the tape-and-reel packaging variant of the UC3842D. Confirm the manufacturer is Texas Instruments to ensure compatibility with original specifications. Check for the 'g4' suffix if lead-free compliance is required, as this denotes a specific environmental designation. Ensure the operating temperature range matches the application requirements, typically 0°C to 70°C for this grade. Validate the pinout against the 14-pin SOIC package diagram before integration.

Power Supply Controllers, Monitors Selection Notes

Select the UC3842DTR when current-mode control is preferred for its inherent line feedforward and simple slope compensation. Choose this part over voltage-mode controllers for better transient response and easier stability analysis. Consider the 500 kHz maximum frequency limit when designing transformer and filter components. Ensure the input voltage stays within the 12 V to 28 V operational window for proper UVLO function. Verify that the thermal performance of the SOIC package suits the expected power dissipation in the target application.

Power Supply Controllers, Monitors Part Context

The UC3842 belongs to the UCx84x family of current-mode PWM controllers from Texas Instruments. This series is widely used in industrial and consumer power supplies due to its robust feature set and ease of use. The UC3842 specifically targets applications requiring moderate switching frequencies and efficient power conversion. It serves as a standard solution for replacing older discrete control circuits or legacy ICs in established power supply designs.

Power Supply Controllers, Monitors Replacement Considerations

The UC3842NG4 is a tube-packaged alternative from Texas Instruments with identical electrical characteristics. The UC3842DW is the die-same variant in a wide-body SOIC package. Verify pin compatibility and thermal resistance differences when substituting these packages. Ensure the replacement part meets the same temperature and voltage specifications.