1N4148 diode is a standard signal P-N junction diode. It has a medium voltage drop of 0.72 V and a low current rating of 300mA.
Hence, the 1N4148 is mainly used for general operations like fast switching, high-speed rectification, and protection of telecommunication devices.
In this post, we will discuss the applications and pinout of the 1N4148 diode. We will also see the equivalents of this diode, which you can use, as its substitute.
Here’s what 1N4148 is used for
The 1N4148 is your go-to diode when it comes to normal use. You can use it in Digital logic circuits, in power supplies due to its fast switching capability and quick recovery time.
It is sometimes used in rectifier circuits where operating voltages are less than 100 V. Although 1N4007 is a better alternative due to its higher reverse voltage ratings.
Is 1N4148 a Zener diode?
No, 1N4148 is not a Zener diode. Although it looks like a Zener diode, it is a normal diode. While a Zener diode is mostly used as a voltage regulator, 1N4148 is used in fast switching applications.
So, what is a 1N4148 Diode?
1N4148 is a type of switching diode. These diodes provide quick switching (up to about 100 MHz) and are popularly used in low-current applications. 1N4148 switching diode was first registered at JEDEC in 1968 for military and industrial applications.
Due to its small size, low cost, and easy availability, it is now the most commonly produced switching diode, replacing the former 1N914 diode.
Features of 1N4148 diode
- The maximum current carrying capacity is 300mA.
- Its recovery time is 8ns.
- The power dissipation for this device ranges from 80mW to 1kW.
Modes of Operation
The diode works similar to a signal diode allowing current flow in a single direction, i.e., from Anode to Cathode. Depending on the way it is connected across a voltage source, there are two modes of operation of 1N4148 diode: Forward biased and Reverse biased.
Forward biased mode: In forward biased mode, it works like a closed switch and allows the current to flow through it.
Reverse biased mode: In reverse bias mode, it works as an open switch and does not allow the current flow.
Below a specified voltage (cutoff voltage), the diode shows high resistance while above that specific voltage, it shows low resistance.
1N4148 diode Pinout
| Pin No. | Pin Name | Polarity | Function |
| 1 | Anode | Positive | The current enters through the Anode |
| 2 | Cathode | Negative | The current exit through the cathode. |
Specifications of 1N4148 diode
The specifications like the operating voltage, working temperature range for the 1N4148 diode are provided in the table below.
| Parameter | Value |
| Package | SMD and DO-35 |
| Diode type | Fast switching Diode |
| Peak repetitive reverse voltage | 100V |
| Working temperature range | (-65°C to 175°C ) |
| Power Dissipation | 5W |
| Peak forward surge current | 2A |
| Forward continuous current | 300mA |
| Reverse recovery time | 8ns |
What are the equivalents of 1N4148?
So, if are looking for an alternative to 1N4148, you can use these diodes:
- 1N914
- 1N916/1N4149
- 1N4446/1N914A
- 1N4447/1N916A
- 1N4448/1N914B
- 1N4449/1N916B
What is 1N4148 diode used for- Applications
Some applications of 1N4148 where it is commonly used are as follows:
- Digital logic circuits
- General and high-speed switching
- Signal filtering
- Rectification
- In different circuits like power supply, voltage double, and battery charger circuits.
- Protection circuits in telecommunication industries, offices, homes, etc.
1N4148 Datasheet(TH and SMD)
1N4148 is available in three types: Axial lead, bolt mount, and Surface mount type.
To download the datasheet of Axial lead through-hole 1N4148 diode, click here.
To download the datasheet of Surface mount 1N4148 diode, click here.
