## Overview of the TSOP322 Series The **TSOP322** series is a collection of miniaturized receivers for infrared (IR) remote control systems. These modules integrate a PIN diode and a preamplifier into a single lead frame, encapsulated in an epoxy package that acts as an IR filter. --- ### Key Specifications | Feature | Specification | | :--- | :--- | | **Supply Voltage (Vs)** | 2.5 V to 5.5 V | | **Supply Current (Is)** | 0.7 mA (typical) | | **Carrier Frequency** | 30 kHz to 56 kHz (depends on sub-model) | | **Transmission Distance** | Up to 45 meters | | **Directivity** | ± 45° (half angle) | | **Output Type** | Active Low (Digital) | --- ### Internal Block Diagram Components The TSOP322 is not just a sensor; it is an Integrated Circuit (IC). The internal structure includes: 1. **PIN Photodiode:** Converts infrared light pulses into electrical signals. 2. **Preamplifier:** Boosts the weak signal from the photodiode. 3. **Automatic Gain Control (AGC):** Adjusts sensitivity to filter out ambient light noise (like sunlight or fluorescent lamps). 4. **Band Pass Filter:** Only allows a specific carrier frequency (e.g., 38 kHz) to pass through. 5. **Demodulator:** Removes the carrier frequency to output a clean digital pulse. --- ### Pin Configuration The TSOP322 typically features three pins. Looking at the sensor from the front (the side with the "bump"): | Pin Number | Name | Description | | :--- | :--- | :--- | | **1** | **OUT** | Data Output (Connects to MCU) | | **2** | **GND** | Ground (0V) | | **3** | **Vs** | Power Supply (2.5V - 5.5V) | --- ### Application Circuit To ensure stable operation, a simple RC filter is recommended at the power supply input to suppress power ripples. ```c +Vs (5V) | [100 Ohm Resistor] |----------[ 4.7uF Capacitor ]--- GND | (Pin 3) +---------+ | TSOP322 |---(Pin 1) Output to Microcontroller +---------+ (Pin 2) | GND ``` --- ### Frequency Selection The "XX" in `TSOP322XX` indicates the carrier frequency. Choosing the correct one is vital for matching your IR transmitter (Remote). * **TSOP32230:** 30 kHz * **TSOP32236:** 36 kHz * **TSOP32238:** 38 kHz (Most common for TV remotes) * **TSOP32240:** 40 kHz * **TSOP32256:** 56 kHz