TL494CN: Overview,parameter,Main uses,Features,application fields,working principle and alternative models


TL494CN Voltage Mode PWM Controller Overview:


The TL494CN is a pulse-width modulation (PWM) control circuit primarily designed for power supply applications. It provides control features for regulating the output voltage of switch-mode power supplies.



  • Supply Voltage: The voltage required for proper operation.
  • Output Current Capacity: Maximum current that can be handled by the output stage.
  • Operating Temperature Range: Temperature range within which the device functions.
  • Frequency Range: Range of frequencies over which PWM can be controlled.
  • Duty Cycle Range: The range of duty cycles achievable with the controller.
  • DataSheet

    TL494CN PDF

Main Uses:

  • Switch-Mode Power Supplies: Regulating output voltage in power supply circuits.
  • DC-DC Converters: Controlling the output voltage in DC-DC converter circuits.
  • Battery Chargers: Providing voltage regulation in battery charging systems.


  • PWM Control: Regulates the duty cycle of the output waveform.
  • Error Amplifier: Compares the feedback voltage to a reference voltage.
  • Soft-Start Function: Controls the startup process to prevent overshoot.
  • Shutdown Function: Allows for easy power down of the controller.
  • Overcurrent Protection: Safeguards against excessive output currents.

Application Fields:

  • Power Electronics: Utilized in various power supply and power management systems.
  • Industrial Applications: Found in industrial power systems and converters.
  • Telecommunications: Power regulation in communication equipment and infrastructure.
  • Renewable Energy: Control circuitry for solar inverters and wind power systems.

Working Principle:

  • Error Amplifier: Compares the reference voltage with the feedback voltage to adjust the PWM output.
  • Oscillator: Generates a triangle waveform for comparing with error amplifier output.
  • Comparator: Compares the error amplifier output with the triangle wave to generate PWM pulses.
  • Output Stage: Drives the power conversion circuitry based on the PWM signal.

Alternative Models:

  • SG3525: An alternative PWM controller chip with similar features and applications.
  • UC3842: Comparable controller commonly used in switching power supply designs.
  • LM5039: Alternative for high-performance power supply control applications.

The TL494CN is a versatile PWM controller widely used in power supply applications due to its features like PWM control, error amplification, and protection mechanisms. Carefully select alternative models like the SG3525 or UC3842 based on specific requirements and compatibility with your power supply design. Refer to datasheets and technical documentation for detailed specifications and performance characteristics when integrating these controllers into your circuits.