Surge Suppression ICs
Surge Suppression ICs (surge suppression integrated circuits) are integrated circuit devices specifically used to suppress transient overvoltage or current surges. They protect sensitive electronic circuits from damage by quickly responding to abnormal voltage/current changes.
1. What are the Core Functions of Surge Suppression IC?
Transient Suppression: Limit the transient voltage amplitude by clamping or absorbing to prevent the circuit from being damaged by overvoltage (such as lightning strikes and electrostatic discharge).
Fast Response: The response time can reach nanoseconds (TVS) or microseconds (TSS), ensuring that the action is completed before the surge reaches the protected circuit.
2. What are the Main Types of Surge Suppression IC?
1) TVS (Transient Voltage Suppressor)
Unidirectional/Bidirectional Protection: Unidirectional TVS only suppresses positive or negative surges, and bidirectional TVS is suitable for AC or positive and negative alternating signal scenarios.
Low Capacitance Design: Suitable for high-speed signal lines (such as USB and HDMI), reducing the impact on signal integrity.
2) TSS (Semiconductor Discharge Tube)
High Surge Withstand Capability: Absorbs large current through a semiconductor structure, often used for lightning protection in communication equipment.
3. What are the Key Parameters of Surge Suppression IC?
Clamping Voltage (Vc): The maximum voltage value allowed by the device during surge, which must be lower than the maximum withstand voltage of the protected circuit.
Breakdown Voltage (Vrwm): The threshold voltage at which the device starts to operate, which must be higher than the normal working voltage of the circuit.
Peak Pulse Current (Ipp): The maximum instantaneous current that the device can withstand, which must match the expected surge intensity.
4. What are Surge Suppression ICs Used for?
Communication Equipment: Protect Ethernet, 5G base stations, etc. from lightning strikes and electrostatic discharge.
Automotive Electronics: Used for vehicle sensors and battery management systems to prevent failure caused by voltage transients.
Industrial Power Supply: Suppress voltage spikes in switching power supplies and motor drives.
5. How to Choose the Adaptable Surge Suppression IC?
Signal Type: For high-speed signals, low-capacitance TVS (such as less than 0.5pF) should be selected, and for ordinary power lines, higher capacitance can be selected.
Working Environment: In high-temperature scenarios, attention should be paid to the temperature resistance of the device (such as the junction temperature range of the TVS).
Integrated Solution: Multi-channel array packaging can simplify PCB layout and improve protection efficiency.
Through reasonable selection and layout, Surge Suppression ICs can significantly improve the reliability and anti-interference ability of electronic systems.
6. Surge Suppression ICs FAQs
1）What are the Causes of Damage to Surge Suppression IC?
Excessive Energy: The surge energy exceeds the joule rating of the device (such as insufficient TVS tube Ipp), and a model with higher current capacity needs to be upgraded.
Improper Layout: The protective device is too far away from the protected circuit, resulting in excessive residual voltage. It is recommended to install it close to the port.
2) What are the Precautions for Designing A Surge Suppression IC?
Ground Consistency: The reference ground of the protective device must be consistent with the system ground path to avoid potential differences causing protection failure.
Electromagnetic Compatibility (EMC): Use spiral inductors or magnetic beads to isolate high-frequency noise and reduce interference with sensitive circuits.