The **TSOP933..DF1P** series (specifically manufactured by Vishay Semiconductors) belongs to a family of miniaturized IR receiver modules designed for infrared remote control systems. These components integrate a photopinhole, a preamplifier, and an internal filter for PCM frequency. --- ## 1. Technical Specifications The ".." in the part number represents the carrier frequency (e.g., TSOP933**38** for 38 kHz). | Parameter | Specification | | :--- | :--- | | **Supply Voltage (Vs)** | 2.0 V to 3.6 V | | **Supply Current** | 0.35 mA (typical) | | **Transmission Distance** | Up to 40 meters | | **Carrier Frequency** | 30 kHz to 56 kHz (model dependent) | | **Output Type** | Active Low | | **Directivity** | $\pm$ 45 degrees | --- ## 2. Key Internal Components The device is a "3-in-1" package that simplifies circuit design: * **Photodiode:** Captures the IR signal. * **Automatic Gain Control (AGC):** Adjusts sensitivity to prevent saturation from bright ambient light. * **Band Pass Filter:** Specifically tuned to the carrier frequency (e.g., 38kHz) to suppress noise. * **Demodulator:** Strips the carrier frequency to provide a digital data signal to the microcontroller. --- ## 3. Application Circuit To ensure stable operation, a simple RC filter is recommended on the supply line to suppress power supply ripples. ```cpp // Schematic Representation: // [VCC] --[ 100 Ohm Resistor ]--+--[ Pin 3: Vs ] // | // [ 4.7uF Cap ] // | // [GND] ------------------------+--[ Pin 2: GND ] // // [MCU Input] <------------------- [ Pin 1: OUT ] ``` --- ## 4. Notable Features of the DF1P Suffix The **DF1P** suffix indicates specific packaging and environmental standards: * **DIP/SMD Variant:** Usually refers to a specific lead-bend or surface-mount orientation. * **Low Power:** Optimized for battery-operated devices (low supply voltage support). * **Immunity:** High robustness against optical noise like CFL lamps or sunlight.