The TL494 is equivalent to the following devices:
Vin (+24V) | +---------------+---------------+ | | | (12) === C1 (D1) VCC 220uF Catch Diode | | | +--+--+ | | | | | | (8) (11) | +---(L1)---+--- Vout (+1.2V to 15V) C1 C2 | | 100uH | | | | | | +--+--+ | [Q1] === C2 | | TIP127 2200uF +---[ R_gate ]--+ PNP | | 100 Ohm | | (9) +----------+ E1 | | GND (10) E2 ---> GND Feedback Signal Regulation Loop
Two operational amplifiers compare feedback voltages against a reference to regulate output voltage or current.
Now that you understand the basics, let's explore how the TL494 is configured for the four most common power conversion tasks. For each application, note how the pin connections—especially the output mode at pin 13—change to suit the topology. tl494 circuit diagram
Advantages:
Inverting input of Error Amplifier 2 (Current reference connection)
Compensation input. Used to stabilize the feedback loop. High voltage on this pin reduces the output pulse width. The TL494 is equivalent to the following devices:
0% to 100% (allows adjusting the "off" time to prevent shoot-through in MOSFETs). 2. TL494 Pin Configuration and Functional Diagram
The IC contains:
The TL494 circuit diagram has a wide range of applications, including: Advantages: Inverting input of Error Amplifier 2 (Current
The oscillator (pins 5 & 6) generates a sawtooth wave. The PWM comparator compares this sawtooth to the error signal from Amps 1 & 2. The output logic then drives the two transistors (Q1/Q2). Pin 4 (DTC) adds an offset to the sawtooth, limiting max duty cycle.
The TL494 is housed in a standard 16-pin dual in-line package (DIP) or surface-mount (SOIC) package. Pin Number Description IN+ (Error Amp 1)
Ultimate Guide to the TL494 Circuit Diagram and Design The TL494 is a highly versatile pulse-width-modulation (PWM) control circuit. It serves as the backbone for switch-mode power supplies (SMPS), DC-to-DC converters, and inverter designs. 1. TL494 Pinout and Internal Architecture
Offers a user-adjustable dead-time minimum. This prevents simultaneous conduction in push-pull configurations, protecting external switching transistors from cross-conduction ("shoot-through").