Tl494 Circuit Diagram [exclusive] Jun 2026

) to pins 5 and 6 to set the rhythm of the internal oscillator.

Timing Capacitor connection; determines the internal oscillator frequency

If high, enables alternate output; if low, single-ended output. tl494 circuit diagram

) as short as possible and place them close to the IC to prevent stray electromagnetic interference (EMI) from distorting the internal sawtooth wave.

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.

: The switching frequency can be finely tuned by selecting specific values for an external resistor ( Rtcap R sub t ) and capacitor ( Ctcap C sub t ) connected to pins 5 and 6. +-------------------+ | TL494 | | | | Pin

A basic TL494 circuit diagram is shown below:

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

: Allows users to set a specific "dead time" to prevent switching overlap and protect power transistors. Uncommitted Output Transistors Pin 13, the Output Control, acts as a logic toggle

The combined emitter output drives a single high-side power switch, which channels current into a smoothing inductor, a freewheeling diode, and an output filtering capacitor. 5. Design Checklist and Troubleshooting Tips

If you are not utilizing the secondary error amplifier (Pins 15 and 16) for current sensing, do not leave them floating. Tie the non-inverting input (Pin 16) to Ground and the inverting input (Pin 15) to VREF. This keeps the unused amplifier output low, preventing unexpected noise from overriding your primary control loop. Bypass Capacitors: Place a high-quality

A standard TL494 circuit consists of the following key functional blocks: An external capacitor ( CTcap C sub cap T ) and resistor ( RTcap R sub cap T ) set the operating frequency.

| Module | Pin | Symbol | Function Description | | :--- | :--- | :--- | :--- | | | 1 | 1IN+ | Non-Inverting Input of Error Amplifier 1 | | | 2 | 1IN- | Inverting Input of Error Amplifier 1 | | | 16 | 2IN+ | Non-Inverting Input of Error Amplifier 2 | | | 15 | 2IN- | Inverting Input of Error Amplifier 2 | | Control & Regulation | 3 | FEEDBACK | Error Amp Output / PWM Comparator Input | | | 4 | DTC | Dead-Time Control (minimum off-time) | | | 13 | OUTPUT CTRL | Output Mode Select (Push-Pull or Single-Ended) | | Timing Generation | 5 | CT | Timing Capacitor (sets oscillator frequency) | | | 6 | RT | Timing Resistor (sets oscillator frequency) | | Power Supply | 7 | GND | Ground | | | 12 | VCC | Positive Power Supply (7V to 40V) | | | 14 | VREF | 5V Reference Voltage Output | | Output Driver | 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 |

Comprehensive Guide to TL494 Circuit Diagrams: Design, Pinout, and Applications