Set up the to regulate the output voltage, typically using a voltage divider from the output to 1IN- . Step 3: Running a Transient Simulation To see the PWM signals:
After downloading, extract the archive to the sym/ValVol folder.
: The TL494’s output transistors can only directly drive small-signal transistors, not large power MOSFETs. Many engineers use gate drive transformers (GDTs) to isolate the control IC from the power stage. In LTspice, GDTs introduce additional inductances that can dramatically slow down the simulation unless modeled carefully. tl494 ltspice
To test the model, it is recommended to set up a simple buck converter topology in LTspice. Connect a resistor RTcap R sub cap T to pin 6 and a capacitor CTcap C sub cap T to pin 5. The frequency is calculated as:
When simulating this configuration, several specific issues arise: Set up the to regulate the output voltage,
is a versatile fixed-frequency PWM control integrated circuit, widely used in power electronics for buck, boost, and push-pull converter designs
For secondary-side synchronous rectification, some designers use two TL494 ICs — one for primary-side switching and one for secondary-side synchronous MOSFETs. These ICs can be synchronized by connecting the oscillator output of the master to the DTC pin of the slave. The datasheet discusses the synchronization start-up issues to be aware of. Many engineers use gate drive transformers (GDTs) to
Use the standard TL494 timing formula to calculate your target components:
Simulate a load transient to see how the TL494 adjusts the PWM duty cycle to maintain a stable output voltage.