The **TSOP11.. series** (specifically the TSOP11xx family) consists of miniaturized receivers for infrared (IR) remote control systems. These components integrate a PIN diode and a preamplifier on a single lead frame, while the epoxy package acts as an IR filter. --- ## 1. Internal Architecture The TSOP11.. is more than just a phototransistor; it is a sophisticated Integrated Circuit (IC). Internally, it consists of: * **PIN Photodiode:** Converts IR light into an electrical signal. * **Preamplifier:** Boosts the weak signal from the diode. * **Automatic Gain Control (AGC):** Adjusts sensitivity to suppress ambient noise. * **Band Pass Filter:** Only allows signals of a specific carrier frequency (e.g., 38kHz) to pass. * **Demodulator:** Removes the carrier wave and outputs the original data pulses. --- ## 2. Technical Specifications Typical parameters for the TSOP11 series are summarized below: | Parameter | Value/Range | | :--- | :--- | | **Supply Voltage (Vcc)** | 2.7V to 5.5V | | **Supply Current (Is)** | ~0.7 mA | | **Carrier Frequency ($f_0$)** | 30 kHz to 56 kHz (variant dependent) | | **Transmission Distance** | Up to 35 meters | | **Directivity** | $\pm 45^\circ$ (Half angle) | | **Output Type** | Active Low (Logic 0 when IR is detected) | --- ## 3. Pin Configuration The TSOP11.. usually features a standard 3-pin layout: 1. **Pin 1 (OUT):** Data output; connects to a microcontroller interrupt or I/O pin. 2. **Pin 2 (GND):** Ground connection. 3. **Pin 3 (Vs):** Power supply voltage. --- ## 4. Key Features for Designers * **Disturbance Immunity:** It is designed to be highly robust against noise from sunlight, fluorescent lamps, and LCD backlights. * **Frequency Matching:** The "11" in the name is followed by two digits indicating the carrier frequency. For example: * **TSOP1138:** Optimized for 38 kHz. * **TSOP1140:** Optimized for 40 kHz. * **Application Circuit:** To ensure stability, it is recommended to place a resistor ($R_1 \approx 100 \Omega$) in series with $V_s$ and a capacitor ($C_1 \approx 4.7 \mu F$) between $V_s$ and $GND$ to filter power supply noise. ```text Basic Connection Diagram: [ Vcc ] | [R1: 100 Ohm] |--------+---- (Pin 3: Vs) | [C1: 4.7uF] | | +--------+---- (Pin 2: GND) | +---- (Pin 1: OUT) --> [Microcontroller] ``` --- ## 5. Typical Applications * TV, DVD, and Hi-Fi remote control receivers. * Infrared air conditioning controls. * Optical proximity sensors (when used with an IR LED). * Simple wireless data transmission.