1N4987

Overview and General Description
The 1N4987 is a high-performance, general-purpose diode from Microchip Technology designed primarily for use in rectification, voltage clamping, and protection circuits. This diode is built to handle moderate to high voltage levels and can operate efficiently in various industrial and consumer electronic applications. The 1N4987 is widely used in power supplies, automotive circuits, audio amplifiers, and other systems requiring reliable diode performance for rectification or protection.

The 1N4987 is a part of the 1N series of diodes, which are renowned for their robustness and excellent reliability. This particular diode is optimized for use in applications where high surge current capability and low forward voltage drop are critical for optimal system performance. The 1N4987 provides superior performance in both AC and DC rectification and offers a solid solution for overvoltage protection in sensitive circuits.

Electrical Characteristics and Performance
The 1N4987 is designed with a peak repetitive reverse voltage (V\_RRM) of 100V, making it suitable for use in systems where moderate to high reverse voltage protection is required. It has a forward current rating (I\_F) of 1A, providing adequate current handling capabilities for various medium-power applications. Additionally, the diode features a low forward voltage drop (V\_F), which improves efficiency by minimizing power losses in the circuit.

* Peak Reverse Voltage (V\_RRM): 100V
* Forward Current (I\_F): 1A continuous
* Average Forward Voltage Drop (V\_F): Typically 1.1V at 1A
* Reverse Current (I\_R): Typically 5μA at 100V
* Reverse Recovery Time (t\_rr): Typically 5ns

Surge Current Handling and Power Dissipation
One of the key advantages of the 1N4987 is its ability to handle surge currents without damage, which is essential for applications with transient voltage spikes. The diode can withstand a peak surge current of up to 30A, allowing it to absorb high-energy pulses without failure. This makes the 1N4987 ideal for applications in environments with high transient conditions, such as automotive circuits, power supplies, and industrial machinery.

* Surge Current (I\_S): 30A (single cycle, 8.3ms)
* Power Dissipation (P\_D): 3W (maximum)
* Thermal Resistance Junction to Ambient (RthJA): 75°C/W

Reverse Recovery Characteristics
The 1N4987 is a fast-recovery diode, which is important for high-speed switching applications. It features a low reverse recovery time (t\_rr) of approximately 5ns, enabling the diode to switch quickly between conducting and non-conducting states. This characteristic is essential for applications such as switching power supplies, where fast switching is required to maintain efficiency and minimize energy losses.

* Reverse Recovery Time (t\_rr): 5ns
* Reverse Recovery Charge (Q\_R): 20nC (at 1A, 50V)

Thermal and Environmental Specifications
The 1N4987 is built to withstand a wide operating temperature range, making it suitable for use in both industrial and automotive environments. The diode can operate effectively from –65°C to +150°C, ensuring that it remains reliable under temperature extremes. The device's thermal management features are also optimized, with a maximum junction temperature of 150°C, which helps ensure that the diode can handle prolonged high-current conditions without degradation.

* Operating Temperature Range (Tj): –65°C to +150°C
* Storage Temperature Range (Tstg): –65°C to +150°C
* Junction-to-Case Thermal Resistance (RthJC): 25°C/W

Package and Mounting
The 1N4987 comes in a DO-41 axial package, which is a widely used form factor for diodes in both through-hole and surface-mount designs. The DO-41 package allows for easy integration into both automated and manual assembly processes, providing a reliable connection for current handling and heat dissipation. The leads are designed to be easily soldered onto a PCB, and the package also provides adequate space for heat dissipation during operation.

* Package Type: DO-41 axial leaded
* Package Dimensions: Length: 4.6mm, Width: 2.8mm, Height: 7.8mm
* Lead Length: 22.5mm (typical)
* Mounting Type: Through-hole or axial lead

Applications
The 1N4987 diode is used in a wide range of applications where reliable voltage protection and rectification are required. Some of the primary uses include:

* Power Supplies: Used for rectification and voltage regulation in both AC and DC power supplies.
* Automotive Circuits: Protection against reverse voltage and transient spikes in automotive electrical systems.
* Audio Amplifiers: Used in signal rectification and voltage regulation in audio amplifiers.
* Surge Protection: Used in systems where high-energy pulses or voltage spikes need to be clamped or absorbed.
* Industrial Control Systems: Ideal for protection in power control and automation circuits that involve high voltages or large current spikes.

Key Specifications Summary

* Peak Reverse Voltage (V\_RRM): 100V
* Forward Current (I\_F): 1A continuous
* Forward Voltage Drop (V\_F): 1.1V at 1A
* Reverse Current (I\_R): 5μA at 100V
* Surge Current (I\_S): 30A (single cycle, 8.3ms)
* Reverse Recovery Time (t\_rr): 5ns
* Power Dissipation (P\_D): 3W
* Operating Temperature Range (Tj): –65°C to +150°C
* Junction-to-Ambient Thermal Resistance (RthJA): 75°C/W
* Package: DO-41 axial leaded

Conclusion
The Microchip Technology 1N4987 is a versatile and robust diode designed for medium-power rectification, voltage clamping, and surge protection applications. With its high surge current capability, low forward voltage drop, and fast switching characteristics, the 1N4987 is an excellent choice for applications requiring reliable performance under transient conditions. Its wide operating temperature range and reliable protection features make it ideal for use in automotive, industrial, and consumer electronics applications where high efficiency and long-term durability are required.