(Pin 12) to the positive 12V rail. Connect GND (Pin 7) to the negative rail. Place a
). When the circuit achieves equilibrium, the error amplifier dynamically matches the voltage on Pin 1 to the target reference benchmark set on Pin 2.
The TL494 circuit consists of several key components:
What are you planning to build (e.g., inverter, buck converter, push-pull)? tl494 circuit diagram
resistor to ensure minimum dead-time (maximum duty cycle). To include a soft-start function, add an electrolytic capacitor (
The TL494 is a versatile, industry-standard PWM control chip used extensively in switch-mode power supplies (SMPS), DC-to-DC converters, and inverter designs. Introduced decades ago, its reliability, dual-error amplifiers, and precise dead-time control keep it highly relevant for modern power electronics engineers and hobbyists alike.
Controls the minimum dead time between output pulses. Applying 0V allows maximum duty cycle (approx. 45% per output), while 3.3V or higher shuts down the outputs completely. (Pin 12) to the positive 12V rail
The chip contains an internal 5.0V bandgap reference voltage accessible via . This voltage serves as a highly stable reference point for the error amplifier networks. It can source up to 10mA of current to external biasing resistors. The Oscillator Circuit
The is a fixed-frequency, pulse-width modulation (PWM) control IC, widely used in switching power supplies, DC-DC converters, battery chargers, and inverters. Understanding its circuit diagram is essential for designing efficient power electronics.
If you are not utilizing the secondary error amplifier (Pins 15 and 16) for current sensing, do not leave them floating. Tie the non-inverting input (Pin 16) to Ground and the inverting input (Pin 15) to VREF. This keeps the unused amplifier output low, preventing unexpected noise from overriding your primary control loop. Bypass Capacitors: Place a high-quality When the circuit achieves equilibrium, the error amplifier
output (Pin 14) to provide reference voltage for your voltage divider circuit.
What are you building? (e.g., buck, boost, push-pull, half-bridge)
. The internal oscillator generates a sawtooth wave across the CTcap C sub cap T capacitor.
