is the "Swiss Army Knife" of power electronics, a classic integrated circuit that has been a staple in switch-mode power supplies (SMPS) for decades. At its core, the TL494 is a fixed-frequency, pulse-width modulation (PWM) controller that puts an entire control system—oscillators, error amplifiers, and output transistors—on a single 16-pin chip. Inside the Machine: Key Components
Pin 13, the Output Control, acts as a logic toggle. The circuit diagram shows this pin connected to the internal flip-flop. When Pin 13 is tied to the 5V reference, the internal flip-flop is enabled, and the output transistors (Pins 8, 9, 10, 11) alternate in a push-pull configuration—ideal for driving a center-tapped transformer. When Pin 13 is grounded, the flip-flop is bypassed, and the output transistors switch in parallel. This allows the diagram to reveal the chip's versatility: it can drive a single output stage or a double-ended output stage depending solely on this wiring configuration. tl494 circuit diagram
Resistor and capacitor are connected to determine frequency ( Pin 13 (Output Ctrl): is the "Swiss Army Knife" of power electronics,
Common values for a 50kHz frequency are a 10k resistor and a 2.2nF capacitor. 2. The Power Supply (Pins 12 & 7) The circuit diagram shows this pin connected to
: Features two transistors capable of sinking or sourcing up to 200 mA (or 500 mA in some variants), offering flexibility for driving external loads. Wide Operating Voltage : Functions reliably with a supply voltage range of Pinout Configuration (16-Pin DIP/SOIC) The following pinout is standard for the TL494 controller Description 1IN+, 1IN- Inputs for the first error amplifier. Input for feedback control. Dead-time control comparator input. External capacitor/resistor to set oscillator frequency. Ground terminal. Collector and Emitter for transistor 1. Emitter and Collector for transistor 2. Positive supply voltage. OUTPUT CTRL Selects single-ended (GND) or push-pull (REF) mode. 5V reference output. 2IN-, 2IN+ Inputs for the second error amplifier. Typical Applications
is a versatile fixed-frequency Pulse Width Modulation (PWM) controller IC designed to handle all necessary functions for power-supply control on a single chip. It is widely used in applications like switch-mode power supplies (SMPS) , DC-DC converters, and inverters. Core Features and Specifications Dual Error Amplifiers