The **CMPH2** is a specific part number often associated with **Small Signal N-Channel Enhancement Mode Field Effect Transistors (MOSFETs)**, typically manufactured by companies like Central Semiconductor. Below is a breakdown of the electronic specifications, physical characteristics, and typical applications. ### 1. Technical Specifications The CMPH2 is designed for low-power, high-speed switching applications. | Parameter | Symbol | Typical Value | | :--- | :--- | :--- | | **Drain-Source Voltage** | $V_{DS}$ | 50V - 60V | | **Gate-Source Voltage** | $V_{GS}$ | ±20V | | **Continuous Drain Current** | $I_D$ | 200mA - 500mA | | **Power Dissipation** | $P_D$ | 350mW | | **Gate Threshold Voltage** | $V_{GS(th)}$ | 1.0V to 2.5V | | **Drain-Source On-Resistance** | $R_{DS(on)}$ | < 5.0 $\Omega$ | --- ### 2. Package and Pinout The CMPH2 usually comes in a **SOT-23** surface mount package, which is standard for miniature electronic circuits. | Pin Number | Terminal Name | Function | | :--- | :--- | :--- | | 1 | **Gate (G)** | Controls the flow of current between Drain and Source. | | 2 | **Source (S)** | The terminal where the majority of carriers enter the channel. | | 3 | **Drain (D)** | The terminal where the majority of carriers leave the channel. | --- ### 3. Key Electronic Characteristics * **N-Channel Enhancement Mode:** This means the device is "Normally OFF." It requires a positive voltage on the Gate relative to the Source to allow current to flow. * **High Input Impedance:** Because it is a MOSFET, it draws almost no current at the gate, making it ideal for interfacing with low-power microcontrollers. * **Fast Switching Speed:** It can turn on and off in nanoseconds, suitable for digital logic and pulse-width modulation (PWM). --- ### 4. Common Applications Due to its low current rating and small size, the CMPH2 is commonly used in: 1. **Level Shifting:** Converting logic signals between different voltage levels (e.g., 3.3V to 5V). 2. **Small Relay/LED Driving:** Acting as a switch to control small loads from a GPIO pin. 3. **Signal Switching:** Routing low-power analog or digital signals in complex circuits. --- ### 5. Sample Usage (Schematic Logic) To use the CMPH2 as a simple switch for an LED: ```text [VCC] --- [Resistor] --- [LED] --- [Drain (3)] | [MCU Pin] ------------------------- [Gate (1)] | [GND] ----------------------------- [Source (2)] ```