!link!: Tl494 Ltspice
: Frequency is set by external components ( RTcap R sub cap T CTcap C sub cap T
What to watch:
TI provides official PSpice models on the TL494 product page. These models are generally compatible with LTspice.
: The graphical symbol file used to place the component on your LTspice schematic. 2. Map the Files to Your LTspice Directories tl494 ltspice
nodes to view crisp, cleanly modulated square-wave PWM drive pulses. Troubleshooting Simulation Anomalies
The internal oscillator requires an initial electrical imbalance to begin running in software. If your simulation shows a flat line on the CT pin:
* Oscillator (Pins 5, 6) * Note: Frequency depends on Rt/Ct. Simplified behavioral ramp here. * We generate a 0-3V sawtooth. A1 5 7 OSC RAMP=3 FREQ=100k * Note: Real implementation uses current source I=V(14)/Rt into Ct. : Frequency is set by external components (
Pin 4 controls the minimum dead time between alternating output pulses to prevent shoot-through currents.
Connect Pin 13 directly to GND . Both output transistors switch simultaneously, permitting a maximum duty cycle near
: This contains the mathematical TL494 SPICE model . If your simulation shows a flat line on
Connect 1IN+ to a feedback voltage divider from the output, and 1IN- to a 2.5V reference (or to VREFcap V sub cap R cap E cap F end-sub via a resistor). Output Stage: Connect E1/E2 to drive a MOSFET gate. 4. Configuring Transient Analysis ( .tran ) To see the PWM in action, use a transient analysis.
Test your gate driver isolation and dead-time logic before moving to hardware.