Simulating the in LTspice is a common task for power electronics, but it requires specific third-party models because Texas Instruments does not provide an official SPICE model [13, 19, 27]. Finding and Installing the Model Since there is no built-in component, you must source a (subcircuit) or (schematic-based) model from the community: LTspice Groups.io LTspice Groups.io
| Pin | Name | Function | |-----|---------|------------------------------| | 1 | IN1+ | Non-inverting input of error amp 1 | | 2 | IN1- | Inverting input of error amp 1 | | 3 | FEEDBACK| PWM comparator input (usually from amps) | | 4 | DTC | Dead-time control (0–3V) | | 5 | CT | Timing capacitor | | 6 | RT | Timing resistor | | 7 | GND | Ground | | 8 | C1 | Output transistor 1 collector | | 9 | E1 | Output transistor 1 emitter | | 10 | E2 | Output transistor 2 emitter | | 11 | C2 | Output transistor 2 collector | | 12 | VCC | Supply (7V–40V) | | 13 | OUT CTRL| Output control (GND=parallel, Vref=push-pull) | | 14 | VREF | 5V reference output | | 15 | IN2- | Inverting input of error amp 2 | | 16 | IN2+ | Non-inverting input of error amp 2 | tl494 ltspice
* Output Transistors (Pins 8,9,10,11) * Q1 (Pins 8 Coll, 9 Emit) * Q2 (Pins 10 Coll, 11 Emit) S1 8 9 101 0 SW S2 10 11 101 0 SWLet's verify the model by building a simple open-loop Buck converter. Simulating the in LTspice is a common task
A common way to verify the TL494 model is by simulating a standard buck converter. LTSpice - Importing a New Component Model for Simulation LTSpice - Importing a New Component Model for Simulation 1
LTspice does not include a TL494 model by default. You have three options:
The TL494 is a legendary integrated circuit in the world of power electronics. Introduced in the late 1970s by Texas Instruments, this fixed-frequency pulse-width modulation (PWM) controller has become a staple in switch-mode power supplies (SMPS), DC-DC converters, UPS systems, and battery chargers. Its longevity is a testament to its robustness: dual error amplifiers, a flexible output stage, dead-time control, and a wide operating voltage range (7V to 40V).
Parameters (adjust as needed) .param Vref=5