1N4746AP
Single 18V Zener diodes with 1W power rating in DO-41 package
Manufacturer： microsemi
series introduction
# Introduction to the 1N4746AP Product Series
## 1. Overview
The 1N4746AP is a well - known and widely used product series within the realm of semiconductor components, specifically belonging to the category of Zener diodes. Zener diodes are a crucial type of electronic device that play a vital role in voltage regulation and protection circuits. The 1N4746AP series is designed to offer reliable and precise performance, making it a popular choice among engineers and designers in various electronic applications.
## 2. Key Specifications
### Electrical Characteristics
- **Zener Voltage (Vz)**: The 1N4746AP has a specified Zener voltage. For this series, the Zener voltage is typically around 18V. This means that when the diode is reverse - biased and the voltage across it reaches approximately 18V, the Zener breakdown occurs, and the diode starts to conduct current in the reverse direction while maintaining a relatively stable voltage across its terminals.
- **Power Dissipation (Pd)**: It can handle a certain amount of power. Usually, the 1N4746AP has a power dissipation rating of around 1W. This parameter is important as it determines the maximum power the diode can dissipate without getting damaged. Exceeding this power limit can lead to overheating and potentially cause the diode to fail.
- **Dynamic Resistance (Rz)**: The dynamic resistance of the 1N4746AP is relatively low. A low dynamic resistance indicates that the Zener voltage remains more stable over a range of currents. This is beneficial in applications where a constant voltage is required, as it helps to minimize voltage fluctuations due to changes in the load current.
### Physical Characteristics
- **Package Type**: The 1N4746AP is commonly available in a DO - 41 package. This is a standard through - hole package that is easy to mount on printed circuit boards (PCBs). The DO - 41 package has two leads, which simplifies the soldering process and allows for straightforward integration into electronic circuits.
- **Dimensions**: The DO - 41 package has well - defined dimensions. The overall length of the package is typically around 5.2mm, and the diameter is approximately 2.7mm. These dimensions make it suitable for use in a variety of PCB designs, whether it's a small - scale prototype or a large - scale production board.
## 3. Working Principle
When a Zener diode like the 1N4746AP is forward - biased, it behaves like a normal diode, allowing current to flow easily in the forward direction with a small forward voltage drop (usually around 0.7V for silicon diodes). However, when it is reverse - biased, a unique phenomenon occurs. As the reverse voltage across the diode increases, at a certain point (the Zener voltage), the diode enters the Zener breakdown region. In this region, the diode starts to conduct a significant amount of current in the reverse direction, and the voltage across it remains relatively constant at the Zener voltage. This property is exploited in voltage regulation circuits to maintain a stable output voltage.
## 4. Applications
### Voltage Regulation
One of the primary applications of the 1N4746AP is in voltage regulation circuits. In power supplies, for example, the output voltage may vary due to changes in the input voltage or the load current. By using a 1N4746AP Zener diode in a voltage regulator circuit, the output voltage can be stabilized at the Zener voltage (18V in this case). This is achieved by connecting the Zener diode in parallel with the load, and a series resistor is used to limit the current through the diode.
### Over
Images for reference
2EZ19D5
1N47, 2EZ Series Side