Tl494 Circuit Diagram |verified| 〈FHD〉

Dead-Time Control input. Sets the minimum off-time between pulses.

The TL494 comes in a 16-pin package (DIP or SOP). Understanding the function of each pin is crucial for constructing any TL494 circuit diagram. Description IN+1, IN-1 Input terminals for Error Amplifier 1 Feedback terminal, output of both error amplifiers Dead-Time Control; sets minimum dead time Timing capacitor connector Timing resistor connector Ground terminal Collector and Emitter of Output Transistor 1 Emitter and Collector of Output Transistor 2 Supply voltage (input) OUTPUT CTRL Output mode selection (Push-pull or Single-ended) Reference Output IN-2, IN+2 Input terminals for Error Amplifier 2 Core TL494 Circuit Components

fout=12⋅RT⋅CTf sub o u t end-sub equals the fraction with numerator 1 and denominator 2 center dot cap R sub cap T center dot cap C sub cap T end-fraction

Non-inverting input to the first error amplifier (usually voltage sensing). IN- (Error Amp 1) Inverting input to the first error amplifier. 3 Feedback / PWM Compensation Input for feedback compensation or external PWM control. 4 DTC (Dead-Time Control) tl494 circuit diagram

Always use a fuse and a "Dead-Time" margin on Pin 4 when building high-power inverters to prevent "shoot-through" (where both output transistors are on at once).

A DC motor's speed can be efficiently controlled by varying the PWM duty cycle of the voltage applied to it. The TL494 is well-suited for this task.

This article explores the internal architecture of the TL494, breaks down its pin configuration, analyzes standard circuit diagrams, and provides step-by-step guidance on designing your own functional TL494-based system. 1. Internal Architecture and Functional Block Diagram Dead-Time Control input

If the output voltage drifts high, the voltage at Pin 1 exceeds Pin 2. The error amplifier drives the internal PWM comparator to shrink the pulse width, restoring balance. Step 4: Driver Interface to External MOSFETs

) connected to pins 6 and 5, respectively. This creates a sawtooth waveform that defines the fixed switching frequency. Dual Error Amplifiers

: Two high-gain amplifiers (pins 1, 2 and 15, 16) are used to monitor output voltage and current for feedback control. Understanding the function of each pin is crucial

+---_---+ 11N+ |1 16| 2IN- 11N- |2 15| 2IN+ FEED |3 14| REF (5V) DT |4 13| CTRL CT |5 12| VCC RT |6 11| C1 GND |7 10| E1 C2 |8 9| E2 +-------+ Pin Description Table Pin Number Function Description Non-inverting input of Error Amplifier 1 2 Inverting input of Error Amplifier 1 3 Compensation/Feedback input; accesses PWM comparator 4 Dead-Time Control; sets minimum blanking time 5 Timing Capacitor connection for frequency setting 6 Timing Resistor connection for frequency setting 7 Ground reference 8 Collector terminal of Output Transistor 1 9 Emitter terminal of Output Transistor 1 10 Emitter terminal of Output Transistor 2 11 Collector terminal of Output Transistor 2 12 Positive supply voltage input (7V to 40V) 13 OUTPUT CTRL Output Mode Control (GND = Single-ended, REF = Push-Pull) 14 5V Reference Regulator Output 15 Non-inverting input of Error Amplifier 2 16 Inverting input of Error Amplifier 2 Key Internal Components 5V Internal Reference: Pin 14 provides a stable 5V output (

| 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 |

Connecting an RC network to Pin 4 forces the duty cycle to start at 0% upon power-up and gradually widen to its regulated value, preventing massive current spikes. Step 3: Voltage Feedback Regulation Loop

The switching frequency of the TL494 is established by choosing the right combination of RTcap R sub cap T CTcap C sub cap T