Grounding Pin 4 provides the default minimum dead-time of roughly 3%.
Internal Reference (5V) R_ref 14 0 1k E_ref 14 0 VALUE=5.0
To inject custom dead-time dynamically during simulation, connect a voltage source or a resistor divider to Pin 4. A voltage ranging from scales the dead-time up to 100%. Step 3: Setting Up a Test Simulation Circuit tl494 ltspice
Purpose: simulate PWM balancing and deadtime effects for transformer drive.
: The DTC comparator adds a minimum off-time to the output pulses, preventing cross-conduction in power stages. The internal voltage on this comparator is nominally about 0.12V (or 0.1V, depending on the model version), which corresponds to a minimum dead time of about 3% to 5%. To adjust the dead time, you apply an external voltage between 0V and 3.3V to pin 4. Simply grounding this pin is not recommended unless you are sure you want the minimum possible dead time, as it can lead to shoot-through in your power stage. Grounding Pin 4 provides the default minimum dead-time
Key notes:
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. Step 3: Setting Up a Test Simulation Circuit
By following these steps, you can fully utilize to design, debug, and optimize your TL494 -based power supply circuits effectively.