## TSSP40..SS1XB Series: High-Gain IR Sensor Modules The **TSSP40..SS1XB** series (specifically manufactured by Vishay) consists of compact infrared (IR) receiver modules designed for **proximity sensing** and **reflective sensing** applications. Unlike standard IR receivers used for remote controls, these are optimized for continuous carrier wave detection. --- ### 1. Key Technical Specifications The specific part number varies based on the carrier frequency (e.g., TSSP4038 operates at 38 kHz). | Parameter | Value / Range | Unit | | :--- | :--- | :--- | | **Supply Voltage (Vs)** | 2.5 to 5.5 | V | | **Supply Current (Is)** | 0.7 (typical) | mA | | **Carrier Frequency** | 38, 56 (model specific) | kHz | | **Transmission Distance** | Up to 8 (Direct) | m | | **Operating Temperature** | -25 to +85 | °C | | **Output Type** | Active Low (Open Collector) | - | --- ### 2. Internal Architecture The module integrates several electronic components into a single three-pin package (Side View or Top View depending on suffix): 1. **Photo Diode:** A high-sensitivity PIN diode that converts incoming IR light into electrical current. 2. **Preamplifier:** Boosts the weak signal from the photodiode. 3. **Band Pass Filter (BPF):** Removes noise and only allows the specific carrier frequency (e.g., 38 kHz) to pass. 4. **Demodulator:** Converts the pulsed IR signal into a logic level (High/Low). 5. **Automatic Gain Control (AGC):** Adjusts sensitivity to compensate for ambient light interference. --- ### 3. Pin Configuration These parts typically follow a standard 3-pin layout: | Pin Number | Name | Function | | :--- | :--- | :--- | | **1** | **OUT** | Data Output (Active Low) | | **2** | **GND** | Ground | | **3** | **Vs** | Supply Voltage | --- ### 4. Circuit Implementation To ensure stable performance, a simple RC filter is recommended for the supply line to suppress power noise. ```c // Typical Connection Schematic // [IR Receiver] [Microcontroller] // Pin 1 (OUT) --------> GPIO Input (with pull-up) // Pin 2 (GND) --------> GND // Pin 3 (Vs) --[100R]-- VCC (3.3V or 5V) // | // [4.7uF Cap] // | // GND ``` --- ### 5. Primary Applications Unlike the TSOP series (meant for data communication), the **TSSP** series is designed for fixed-gain applications where the presence/absence of an IR beam is required: * **Proximity Sensors:** Detecting an object approaching a device. * **Reflective Sensors:** Measuring the reflection of an IR LED off a surface. * **Light Barriers:** Used in "trip-wire" security or counting systems. * **Optical Encoders:** Sensing rotation or movement in mechanical parts.