SMBJ18A

The SMBJ18A is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed to protect sensitive electronic components from voltage spikes and transients. This device is particularly useful in applications where overvoltage protection is critical, such as in telecommunications, automotive electronics, and consumer electronics.

Key Features:

1. Voltage Rating: The SMBJ18A has a breakdown voltage of approximately 18 volts, making it suitable for clamping voltage spikes that exceed this threshold while allowing normal operation below it.

2. Power Dissipation: The device is capable of handling a peak power dissipation of up to 600 watts, which allows it to absorb significant energy from transient events without failing.

3. Package Type: The SMBJ18A is housed in a DO-214AA (SMB) package, which is a surface-mount device (SMD) that provides a compact footprint for easy integration into circuit boards. The package is designed for efficient thermal management, ensuring that heat generated during operation is dissipated effectively.

4. Response Time: The SMBJ18A features a fast response time, typically in the nanosecond range, allowing it to react quickly to transient events and protect downstream components from damage.

5. Clamping Voltage: The clamping voltage is specified at a certain peak pulse current, ensuring that the device will limit the voltage to a safe level during a transient event. This characteristic is crucial for protecting sensitive components.

6. Operating Temperature Range: The device operates effectively over a wide temperature range, typically from -55°C to +150°C, making it suitable for various environmental conditions.

7. Low Leakage Current: The SMBJ18A exhibits low leakage current under normal operating conditions, which helps to minimize power loss and improve overall circuit efficiency.

8. Applications: Common applications for the SMBJ18A include ESD protection, surge protection in power supplies, and safeguarding sensitive ICs in automotive and industrial environments.

Electrical Characteristics:

• Reverse Stand-off Voltage (V_R): 18V
• Breakdown Voltage (V_BR): Typically around 20V
• Clamping Voltage (V_C): Specified at a given peak pulse current
• Peak Pulse Power (P_PP): 600W (for 10/1000μs waveform)
• Capacitance: Low capacitance values, ensuring minimal impact on signal integrity in high-speed applications.

Conclusion:

The SMBJ18A from Littelfuse Inc. is a robust and reliable transient voltage suppressor that provides essential protection for electronic circuits against voltage transients. Its combination of high power handling, fast response time, and compact packaging makes it an ideal choice for a wide range of applications where overvoltage protection is necessary.