REDBULL RAMPAGE 2025
Robin Goomes 1st & Thomas Genon 2nd
Output Transistors (Open Collector) Q1 8 104 9 NPN Q2 11 104 12 NPN .MODEL NPN NPN
(Note: The code above is a highly simplified behavioral model for demonstration. For precision engineering, download the official PSpice model from Texas Instruments and convert the syntax.)
Here’s a solid, practical guide to using the in LTspice .
Set via an external resistor ( RTcap R sub cap T ) and capacitor ( CTcap C sub cap T
: C:\Users\[YourUsername]\Documents\LTspiceXVII\lib\sym\AutoGenerated\ (or a custom subfolder).
For , the internal flip-flop divides the frequency by two for each output stage:
You can create the following circuit in LTspice:
If you only have the .model or .subckt text, drag the text file directly into LTspice, right-click the .subckt TL494 line, and select Create Symbol . Basic Test Bench Configuration
When mapping your schematic symbol to the underlying SPICE subcircuit code, ensure the node sequences match perfectly. Misaligned pin assignments will cause simulation errors or convergence failures. Pin Number Description / SPICE Function Non-inverting input of Error Amplifier 1 2 Inverting input of Error Amplifier 1 3 Compensation/Feedback input; monitors error amp outputs 4 Dead-Time Control input; sets minimum blanking time 5 Timing Capacitor connection for the internal oscillator 6 Timing Resistor connection for the internal oscillator 7 Circuit Ground 8 Collector terminal of Output Transistor 1 9 Emitter terminal of Output Transistor 1 10 Emitter terminal of Output Transistor 2 11 Collector terminal of Output Transistor 2 12 Main Positive Supply voltage input 13 OUTPUT CTRL Mode Select: Ground for single-ended, VREF for push-pull 14 Internal 5.0V reference regulator output 15 Inverting input of Error Amplifier 2 16 Non-inverting input of Error Amplifier 2 3. Setting Up the Core External Components
: Create a 16-pin symbol ( .asy ) that matches the subcircuit's pin order: 1IN+ , 1IN- , FB , DTC , CT , RT , GND , C1 , E1 , E2 , C2 , VCC , OC , REF , 2IN- , 2IN+ [1, 3].
