The **TL494-S16-R** is a specific variant of the widely used TL494 Pulse-Width Modulation (PWM) control integrated circuit. It is primarily designed for power supply control and DC-to-DC conversion. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Package Type** | SOP-16 (Small Outline Package) | | **Output Type** | Push-Pull or Single-Ended | | **Operating Voltage (Vcc)** | 7V to 40V | | **Oscillator Frequency** | 1 kHz to 300 kHz | | **Output Current** | 200 mA (Max) | | **Reference Voltage** | 5.0V (±5% tolerance) | --- ### 2. Internal Functional Blocks The TL494 is a comprehensive fixed-frequency PWM control circuit. Its internal architecture includes: 1. **5V Reference Regulator:** Provides a stable internal supply for the control logic and can power external low-current circuits. 2. **Error Amplifiers:** Two gain-controlled operational amplifiers used to monitor voltage and current for feedback loops. 3. **Oscillator:** Its frequency is determined by an external resistor ($R_T$) and capacitor ($C_T$). 4. **Dead-Time Control (DTC) Comparator:** Provides a non-linear control of the maximum duty cycle to prevent "shoot-through" in power transistors. 5. **Output Control Flip-Flop:** Directs the PWM signal to either one or both output transistors. --- ### 3. Pin Configuration (SOP-16) | Pin No. | Name | Function Description | | :--- | :--- | :--- | | 1, 2 | 1IN+, 1IN- | Error Amplifier 1 inputs (Voltage regulation) | | 3 | Feedback | Input for compensation/feedback loop | | 4 | DTC | Dead-Time Control input | | 5, 6 | CT, RT | External capacitor and resistor for frequency setting | | 7 | GND | Ground | | 8, 9 | C1, E1 | Collector and Emitter of Output Transistor 1 | | 10, 11 | E2, C2 | Emitter and Collector of Output Transistor 2 | | 12 | Vcc | Positive Power Supply | | 13 | Output Ctrl | Mode selection (Ground for single-ended, Vref for push-pull) | | 14 | Vref | 5V Reference Output | | 15, 16 | 2IN-, 2IN+ | Error Amplifier 2 inputs (Current/Protection regulation) | --- ### 4. Common Applications The TL494-S16-R is favored in high-efficiency power systems due to its flexibility: * **PC Power Supplies (ATX):** Used as the primary PWM controller. * **DC/DC Converters:** Buck, Boost, and Flyback configurations. * **Inverters:** Converting DC battery power to AC. * **Motor Control:** Speed regulation using PWM. --- ### 5. Calculation Formula The output frequency for a single-ended application is calculated as: ```text f = 1 / (RT * CT) ``` *Note: For push-pull applications, the frequency at each output pin is half of the oscillator frequency.*