Circuit Diagram !!top!! — Tl494

This 5V reference is the heartbeat of the circuit’s stability. On the diagram, we see lines branching from Pin 14 to various inputs. It serves a dual purpose: it powers the internal logic and provides a stable comparison voltage for the error amplifiers. Without this stable reference depicted in the diagram, the PWM control would drift with temperature and input voltage fluctuations, rendering the circuit useless for precision applications.

If you’ve ever cracked open a PC power supply or a car audio amplifier, there is a very high chance you’ve seen a 16-pin chip labeled . Released decades ago, this integrated circuit remains the "old reliable" of the power electronics world. tl494 circuit diagram

| Pin # | Name | Function | | :--- | :--- | :--- | | 1 | Non-Inverting Input (Error Amp 1) | Usually connected to the voltage feedback. | | 2 | Inverting Input (Error Amp 1) | Connected to a reference voltage. | | 3 | Feedback/PWM Comp | Common point for compensation networks. | | 4 | Dead-Time Control (DTC) | Voltage here controls dead time (0V to 3V). | | 5 | CT | Capacitor for timing oscillator. | | 6 | RT | Resistor for timing oscillator. | | 7 | GND | Ground. | | 8 | C1 | Collector of Output Transistor 1. | | 9 | E1 | Emitter of Output Transistor 1. | | 10 | E2 | Emitter of Output Transistor 2. | | 11 | C2 | Collector of Output Transistor 2. | | 12 | VCC | IC Supply Voltage. | | 13 | Output Control | Selects mode: High = Push-pull, Low = Single-ended. | | 14 | REF | 5V Precision Reference Output. | | 15 | Inverting Input (Error Amp 2) | Usually used for current limiting. | | 16 | Non-Inverting Input (Error Amp 2) | Connected to current sense shunt. | This 5V reference is the heartbeat of the

In push-pull mode, the TL494 can drive two MOSFETs to oscillate a transformer, converting low-voltage DC to high-voltage AC or DC. Design Tips Without this stable reference depicted in the diagram,

Before building a power supply, build this simple test circuit to verify your TL494 works. It outputs complementary square waves without feedback.