1N4148: Small Signal Diode, DO-35, 100V, 300mA, 4ns reverse recovery

The 1N4148 is a high-speed switching diode that offers reliable performance in a compact DO-35 package. It is designed to handle a maximum repetitive reverse voltage (VRRM) of 100V and a DC forward current (IF) of up to 300mA, making it suitable for a wide range of applications. The diode's quick reverse recovery time of 4ns ensures efficient operation in circuits requiring fast switching. The 1N4148 diode features a cathode band marking for easy identification and is available in various packaging options, including bulk, ammo, and tape and reel, to suit different manufacturing needs.

This diode is known for its low forward voltage drop and high surge current capability, with a non-repetitive peak forward surge current (IFSM) of 1.0A for a pulse width of 1.0s, and 4.0A for a pulse width of 1.0μs. Its operating junction temperature range is from -55°C to +175°C, and it has a storage temperature range of -65°C to +200°C, allowing for use in a variety of environmental conditions. The 1N4148's thermal characteristics include a maximum power dissipation of 500mW and a thermal resistance from junction to ambient of 300°C/W.

Key Specifications and Features

  • Maximum Repetitive Reverse Voltage (VRRM): 100V
  • DC Forward Current (IF): 300mA
  • Recurrent Peak Forward Current (If): 400mA
  • Non-repetitive Peak Forward Surge Current (IFSM): 1.0A (1.0s pulse), 4.0A (1.0μs pulse)
  • Storage Temperature Range (TSTG): -65 to +200°C
  • Operating Junction Temperature Range (TJ): -55 to +175°C
  • Power Dissipation (PD): 500mW
  • Thermal Resistance, Junction-to-Ambient (RθJA): 300°C/W
  • Forward Voltage (VF): 0.62 - 1.0V depending on conditions
  • Reverse Leakage (IR): 0.025μA at VR = 20V, 25°C
  • Total Capacitance (CT): 4.0pF at VR = 0, f = 1.0MHz
  • Reverse Recovery Time (trr): 4.0ns

1N4148 Datasheet

1N4148 datasheet (PDF)

1N4148 Substitutes
Equivalent alternate parts that may serve as a substitute for 1N4148, most popular parts first


  • High-speed switching applications
  • Voltage clamping
  • Protection circuits
  • Signal processing



General information

Small signal diodes like the 1N4148 are semiconductor devices that allow current to flow in only one direction, characterized by their ability to switch on and off rapidly. These diodes are commonly used in a variety of electronic circuits for tasks such as rectification, signal modulation, and voltage regulation.

When selecting a small signal diode, engineers consider parameters such as maximum repetitive reverse voltage, forward current capacity, power dissipation, and reverse recovery time. The choice of diode is critical in applications requiring fast switching speeds, as a shorter reverse recovery time allows for quicker transitions between on and off states.

The 1N4148 is notable for its fast switching capability, making it suitable for high-speed applications. Its compact DO-35 package and low forward voltage drop also make it a popular choice for designs where space and power efficiency are important.

In addition to technical specifications, packaging options such as bulk, ammo, and tape and reel are important for manufacturing and assembly processes, influencing the ease of handling and integration into electronic devices.

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