Tl494 Ltspice

Simulation steps:

Warning: Some TI models contain encrypted nodes or syntax that LTspice rejects. You may need to fix line breaks or comment out analog behavioral modeling (ABM) statements.

Key notes:

Notes: This is a condensed, pragmatic starting point — refine slopes, gains, and the oscillator to match TL494 datasheet values (osc frequency set by RT/CT, deadtime control range, internal reference ≈5V, EA gains, output transistor drive limits).

The .step command sweeps the load resistance from 5Ω (1A) to 1Ω (5A) and 10Ω (0.5A). Watch how the duty cycle adjusts to maintain 5V output. tl494 ltspice

Run the simulation. Probe the collector output pins. You should see a PWM signal at ~11 kHz. Vary the voltage at the non-inverting input of error amplifier 1 (pin 2) to see duty cycle modulation.

uses open-collector outputs (Pins 8 and 11). In LTspice, you must provide external pull-up resistors (like a 1k cap V sub i n end-sub Simulation steps: Warning: Some TI models contain encrypted

Verify FB pin is not pulled above ~3.5V, and COMP pin voltage is below sawtooth peak.

: To prevent oscillation and stabilize the loop, place a series RC network (e.g., in series with Probe the collector output pins

A word of caution for KiCad users attempting to use this LTspice model: the subcircuit syntax between LTspice (a derivative of Berkeley SPICE) and Ngspice (which KiCad uses) is not always directly compatible. The subcircuits often reference other models, and their internal syntax may not translate perfectly, leading to errors. It is generally best to keep TL494 simulation work within LTspice itself.

Ensure error amplifier inputs are correct polarity (1IN+ > 1IN- increases duty cycle).