1N4148 Diode 100V, 300mA

1N4148 Diode Overview

The 1N4148 is a popular general-purpose silicon switching diode, widely used in electronic circuits for its fast switching capabilities and reliability. Here are the key specifications and characteristics associated with the 1N4148 diode:

Key Specifications:

• Maximum Reverse Voltage (Vr): 100 V (Peak Inverse Voltage – PIV)
• Maximum Forward Current (If): 300 mA (Continuous Forward Current)
• Forward Voltage Drop (Vf): Typically around 0.7 V to 1.0 V at If = 10 mA
• Reverse Recovery Time (trr): Approximately 4 ns (very fast, suitable for switching applications)
• Operating Temperature Range: -55°C to +150°C
• Package Type: Typically available in DO-35 glass package or surface mount variants.

Characteristics:

• Fast Switching: 1N4148 is known for its fast switching speed, making it suitable for applications where quick response times are necessary.
• Moderate Current Handling: With a maximum forward current rating of 300 mA, it is capable of handling various general-purpose applications.
• Low Leakage Current: In reverse bias, the leakage current is very low (around 25 µA at 25°C), which helps maintain efficiency in applications.

Applications:

1. Switching Circuits: Due to its fast switching characteristics, the 1N4148 is used in digital logic circuits and other switching applications.
2. Rectification: Can be used for small signal rectification where a higher voltage rating is needed.
3. Signal Clipping and Clamping: Protecting circuits by clamping voltage to certain levels.
4. Inversion Circuits: As part of flip-flop designs and other logic gates within integrated circuits.

Circuit Connection:

• Forward Bias: To connect the diode in forward bias configuration, connect the anode to the positive side of the circuit and the cathode to the load or ground. The diode will conduct when the voltage at the anode is higher than the voltage at the cathode by the forward voltage drop.
• Reverse Bias: To connect the diode in reverse bias, the anode should be connected to a lower voltage than the cathode. In this state, the diode will block current flow until the reverse breakdown voltage (100 V for 1N4148) is exceeded.

Example Circuit

In a basic rectifier circuit using the 1N4148, you would place the diode in series with a load. The AC voltage is applied across the combination, allowing the diode to conduct during one half of the AC cycle, thus rectifying the input.

Important Notes:

• Heat Dissipation: While the 1N4148 can handle up to 300 mA, ensure that it is not continuously operated near this limit to avoid overheating and potential damage.
• Avoid Reverse Breakdown: Prolonged exposure to reverse voltages exceeding the 100 V rating can damage the diode.