## TSOP574 Series: Electronic Specifications and Features The **TSOP574** is a miniaturized receiver series for infrared (IR) remote control systems. It is manufactured by Vishay Intertechnology and is designed to detect and demodulate IR signals, providing a digital output that can be directly interfaced with a microcontroller. --- ### 1. Key Internal Components The TSOP574 is an integrated circuit that combines several internal blocks into a single side-view package: * **Photo Diode:** Converts incoming IR light into a small electrical current. * **Preamplifier:** Boosts the weak signal from the photo diode. * **Automatic Gain Control (AGC):** Adjusts sensitivity to suppress noise from ambient light (e.g., sunlight or fluorescent bulbs). * **Band Pass Filter:** Specifically tuned to the carrier frequency (e.g., 38kHz) to filter out unwanted signals. * **Demodulator:** Removes the carrier frequency and outputs the original data pulses. --- ### 2. Technical Specifications The following table highlights the critical electrical characteristics of the TSOP574 series: | Parameter | Value / Range | | :--- | :--- | | **Supply Voltage (Vs)** | 2.5 V to 5.5 V | | **Supply Current (Is)** | 0.7 mA (typical) | | **Carrier Frequencies** | 30, 33, 36, 38, 40, 56 kHz | | **Transmission Distance** | Up to 40 meters (typical) | | **Directivity** | Half angle $\phi = \pm 50^\circ$ | | **Output Type** | Active Low (Open Collector) | --- ### 3. Pin Configuration The TSOP574 typically uses a 3-pin lead frame. Note that the pinout is view-dependent: | Pin Number | Name | Function | | :--- | :--- | :--- | | **1** | **OUT** | Demodulated data output; connects to MCU. | | **2** | **GND** | Ground connection. | | **3** | **Vs** | Power supply (2.5V - 5.5V). | --- ### 4. Application Circuit To ensure stable operation and protect the IC from power supply ripples, a simple RC filter is recommended in the circuit design. ```c // Schematic Representation (Vs) --- [ Resistor 100 Ohm ] ---+--- (Pin 3: Vs) | [ Capacitor 4.7 uF ] | (GND) ---------------------------+--- (Pin 2: GND) (MCU Input) <------------------------- (Pin 1: OUT) ``` --- ### 5. Notable Advantages * **Internal Shielding:** Highly resistant to electrical field interference (EMI). * **Low Power Consumption:** Ideal for battery-operated devices. * **AGC4 Algorithm:** Specifically optimized to handle "noisy" environments with heavy optical interference from energy-saving lamps.