The **2SD667ACTZ-E** is a high-performance NPN silicon epitaxial transistor primarily designed for low-frequency power amplification and vertical deflection output in televisions. --- ### 1. General Specifications This transistor is housed in a **TO-92MOD** package, which is slightly larger than the standard TO-92, allowing for better heat dissipation. | Parameter | Symbol | Value | Unit | | :--- | :--- | :--- | :--- | | **Collector-Base Voltage** | $V_{CBO}$ | 120 | V | | **Collector-Emitter Voltage** | $V_{CEO}$ | 80 | V | | **Emitter-Base Voltage** | $V_{EBO}$ | 5 | V | | **Collector Current (DC)** | $I_C$ | 1 | A | | **Collector Power Dissipation** | $P_C$ | 0.9 | W | | **Junction Temperature** | $T_j$ | 150 | °C | --- ### 2. Key Features * **High Voltage:** Capable of handling $V_{CEO}$ up to 80V, making it suitable for circuits with higher voltage rails. * **High Current Capacity:** Can handle continuous currents up to 1A, which is high for its compact package size. * **Excellent Linearity:** Provides stable gain ($h_{FE}$) characteristics, which is crucial for audio clarity in amplification. * **Complementary Pair:** It is often used alongside the **2SB647** (the PNP version) for push-pull amplifier stages. --- ### 3. Pin Configuration Looking at the flat side of the TO-92MOD package with the leads pointing down: | Pin Number | Designation | Function | | :---: | :--- | :--- | | 1 | **Emitter** | Current exit point | | 2 | **Collector** | Current entry point | | 3 | **Base** | Controls the transistor "gate" | --- ### 4. Typical Applications The 2SD667ACTZ-E is commonly found in the following electronic circuits: 1. **Audio Amplifiers:** Used in the driver stage or low-power output stage. 2. **TV Circuits:** Specifically used in vertical deflection output stages. 3. **Voltage Regulators:** Acts as a pass transistor in small power supplies. 4. **Relay Drivers:** Due to its 1A current rating, it can easily trigger medium-sized relays. --- ### 5. Part Number Breakdown (Suffix Meanings) * **2SD667:** The base part number (NPN low-frequency transistor). * **A:** Represents a specific gain ($h_{FE}$) grouping or voltage refinement. * **CTZ:** Refers to the packaging type (often "Z" indicates radial taping for automated insertion). * **-E:** Indicates that the part is **Lead-Free / RoHS Compliant**.