Ltspice | Tl494

The key to success lies in obtaining a clean, properly corrected model — preferably from Valentin Volodin’s Bordodynov library — and following proper installation procedures. Common issues like output stuck high, waveform overlap, and simulation errors all have well-understood solutions that we’ve documented in this guide.

) of the TL494 macromodel is dictated by the values chosen for RTcap R sub cap T CTcap C sub cap T . The mathematical relationship is expressed as:

: A constant current charges the external timing capacitor ( CTcap C sub cap T ), producing a linear sawtooth wave profile.

What specific are you building? (e.g., Buck, Push-Pull, Half-Bridge) What is your targeted switching frequency ? tl494 ltspice

: Provides a dead-time adjustment to prevent switch overlap.

to name your PWM outputs, feedback nodes, and error amplifier inputs. Decoupling is Key

The TL494 subcircuit contains many internal nodes and A-devices, which can slow down transient simulations — especially when driving MOSFETs through gate drive transformers. The key to success lies in obtaining a

: Use the .include TL494.sub SPICE directive directly on your schematic if you prefer to keep files in a local project folder. ⚡ Step 2: Essential Pin Functions

fOSC=1.1RT×CTf sub cap O cap S cap C end-sub equals the fraction with numerator 1.1 and denominator cap R sub cap T cross cap C sub cap T end-fraction Output frequency equals fOSCf sub cap O cap S cap C end-sub Push-Pull Mode (Pin 13 to VREFcap V sub cap R cap E cap F end-sub ): Output frequency at each pin is halved (

RT=1.2120 kHz×1 nF=10 kΩcap R sub cap T equals the fraction with numerator 1.2 and denominator 120 kHz cross 1 nF end-fraction equals 10 k cap omega In LTspice, place a resistor on RT and a capacitor on CT to observe a sawtooth waveform on the CT pin during transient analysis. 5. Running the Simulation and Analyzing Waveforms The mathematical relationship is expressed as: : A

(initial conditions) command to set voltages on capacitors like the timing capacitor ( cap C sub cap T

To simulate effectively, you must understand the chip's internal logic as detailed in the Texas Instruments TL494 Datasheet . : Frequency is set by RTcap R sub cap T CTcap C sub cap T

Some users prefer to create their own category folder (e.g., sym/ValVol ) by extracting the entire Bordodynov archive into that directory. This keeps third-party models organized.

To make the component permanently available in your LTspice library, move the downloaded files into your local directory:

fOSC2the fraction with numerator f sub cap O cap S cap C end-sub and denominator 2 end-fraction 2. Wiring for Open-Loop Simulation Connect to a 12V DC source.