Add a small amount of series resistance to the timing capacitor ( CT ) or the power supplies to cushion sudden current spikes.
Verify FB pin is not pulled above ~3.5V, and COMP pin voltage is below sawtooth peak.
Third-party models often struggle during initialization or experience convergence problems. If your simulation crashes or fails to switch, apply these fixes: The "Time Step Too Small" Error
Dead Time Control (Pin 4)
: Use a P-Channel MOSFET or a NPN transistor driven by the TL494's uncommitted collectors (Pins 8 and 11).
To simulate a fully functioning buck or push-pull converter converter, you must close the feedback loop using the internal error amplifiers (Pins 1, 2, 15, and 16).
: An interesting observation from the Qorvo tech forum shows that the same TL494 SPICE subcircuit can produce different simulation results when run in LTspice versus QSPICE, another free simulator. This serves as a reminder that simulation results are not absolute truth but are dependent on the software’s underlying algorithms. Always cross-reference your simulation results with datasheet specifications and breadboard prototypes. tl494 ltspice
: Press T on your keyboard to add comments or SPICE directives [6].
Connect DTC to GND to allow maximum duty cycle.
Restart LTspice. The component will appear under the library directory name where you saved the symbol. Method B: Local Folder Installation (Portable) Add a small amount of series resistance to
. In LTspice, ensure these values match your target frequency using the formula
PWM comparator: compare error amp output to oscillator Bpw OUT 0 V= ( V(COMP) > VOSC ? Vcc : 0 ) .ends TL494_BHV .endcode
The combination of Texas Instruments’ TL494 Pulse-Width Modulation (PWM) controller with Analog Devices’ LTspice simulation tool is a potent, albeit often tricky, pairing for power electronics engineers and hobbyists. However, this is not an officially supported configuration, leading to frequent challenges, from sourcing the right files to debugging elusive simulation errors. If your simulation crashes or fails to switch,