: Internal operational amplifiers configured with open-collector outputs, allowing them to share a common feedback node ( FB ) via a logical OR mechanism.
Right-click on the line containing .SUBCKT TL494 ... and select .
To execute a simulation, you must obtain a third-party subcircuit netlist (such as those optimized by Helmut Bordodynov).
models into LTspice. Because LTspice is generally compatible with the SPICE standard, many models for similar double-ended controllers like the can be adapted if a direct TL494 model is unavailable. Pro-Tips for TL494 Simulations Label Your Nets tl494 ltspice
Save this symbol as tl494.asy inside ...\LTspiceXVII\lib\sym . 3. Setting Up the Reference Simulation Circuit
A typical working model is a subcircuit ( .subckt ) that uses:
Since LTspice doesn't include it, you have two main options: To execute a simulation, you must obtain a
Restart LTspice. The component will appear under the library directory name where you saved the symbol. Method B: Local Folder Installation (Portable)
The .step command sweeps the load resistance from 5Ω (1A) to 1Ω (5A) and 10Ω (0.5A). Watch how the duty cycle adjusts to maintain 5V output.
: Allows selection of push-pull or single-ended operation. Pro-Tips for TL494 Simulations Label Your Nets Save
The TL494 is a monolithic PWM controller IC that integrates all the necessary functions for a switching power supply, including a voltage reference, error amplifier, PWM generator, and output drivers. The IC is designed to operate in a wide range of applications, from low-power DC-DC converters to high-power switching power supplies. The TL494 features a voltage-mode control loop, which provides excellent line and load regulation, as well as a high degree of stability.
Once your simulation runs, use LTspice’s powerful analysis tools to refine your design: