SA33A vs SA43A
| Part Number |
|
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| Category | TVS - Diodes | TVS - Diodes |
| Manufacturer | ON Semiconductor | ON Semiconductor |
| Description | TVS DIODE 33VWM 53.3VC AXIAL | TVS DIODE 43VWM 69.4VC AXIAL |
| Package | DO-204AC, DO-15, Axial | DO-204AC, DO-15, Axial |
| Series | MiniMosorb? | MiniMosorb? |
| Type | Zener | Zener |
| Operating Temperature | -55°C ~ 150°C (TJ) | - |
| Mounting Type | Through Hole | Through Hole |
| Package / Case | DO-204AC, DO-15, Axial | DO-204AC, DO-15, Axial |
| Supplier Device Package | Axial | DO-15 |
| Applications | General Purpose | General Purpose |
| Unidirectional Channels | 1 | 1 |
| Voltage - Reverse Standoff (Typ) | 33V | 43V |
| Voltage - Breakdown (Min) | 36.7V | 47.8V |
| Voltage - Clamping (Max) @ Ipp | 53.3V | 69.4V |
| Current - Peak Pulse (10/1000µs) | 9.4A | 7.2A |
| Power - Peak Pulse | 500W | 500W |
| Power Line Protection | No | No |
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1. Are TVS diodes and Zener diodes the same?
TVS diodes and Zener diodes have significant differences in functionality and characteristics, so they are not identical.
Definition and purpose
Zener diode: Zener diode is a diode that uses a PN junction for reverse breakdown. It is mainly used to ensure voltage stability. It has a high resistance state before the reverse breakdown voltage and is in a low resistance state after exceeding this critical point. It is widely used in various voltage stabilizing circuits and reference voltage components.
TVS Diode: TVS diode (Transient Suppression Diode) has surge absorption capability and is mainly used to protect circuits from damage caused by transient high voltages such as surges and electrostatic discharge (ESD). It can absorb a large amount of instantaneous current and voltage in a short period of time, protecting the subsequent equipment or circuits from damage.
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2. What is the difference between TVS and ESD diodes?
The main difference between TVS diodes and ESD diodes is their working principle, application scenarios and characteristics.
Working principle and application scenarios
TVS diodes (Transient Voltage Suppressors): TVS diodes are mainly used to suppress transient voltages and prevent components in the circuit from being damaged by surge voltages. When the two poles of the TVS diode are impacted by reverse transient high energy, it can change the high impedance to low impedance in a very short time, absorb the surge power, and protect the precision components in the circuit1. TVS diodes are suitable for protection against various surge pulses, such as lightning strikes, large-capacity load switching, etc.
ESD diode (Electro-Static discharge): ESD diode is mainly used to prevent static electricity and prevent damage to electronic equipment caused by electrostatic discharge. ESD diodes have low capacitance values, typically between 1 and 3.5 picofarad (PF), to accommodate the rapid changes in electrostatic discharge. ESD diodes are suitable for board-level protection, especially in high-speed USB and I/O interfaces, which have higher requirements for electrostatic discharge.
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3. How do TVS diodes fail?
The failure modes of TVS diodes mainly include short circuit failure, open circuit failure and performance degradation. These failure modes can have a serious impact on the normal operation and protection functions of the circuit.
short circuit fault
Short circuit failure is one of the most common failure modes of TVS diodes. When a TVS diode is short-circuited, it changes to a low-impedance state, allowing a large amount of current to pass through, which may cause the circuit to not function properly and may even damage other circuit components. Causes of short circuit faults include:
Thermal breakdown: In a high temperature environment or when subjected to excessive transient energy impact, the PN junction of the TVS diode may undergo thermal breakdown, resulting in a short circuit.
Over-electrical stress: When the transient pulse energy exceeds the energy that the TVS can withstand, it will cause over-electrical stress damage and even directly cause burnout.
Manufacturing process issues: Such as chip bonding interface voids, mesa defects, strong accumulation layer or strong inversion layer on the surface, chip cracks, uneven impurity diffusion, etc., which may cause short circuit failures of TVS diodes during manufacturing or use.
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4. How fast are TVS diodes?
TVS diodes are very fast and can respond within 10^-12 seconds (i.e. 1 nanosecond). When the two poles of the TVS diode are impacted by reverse transient high energy, it can change the high impedance between its two poles into low impedance in a very short time, while absorbing surge power up to several kilowatts, reducing the voltage between the two poles. It is clamped to a predetermined safe value, thereby effectively protecting precision components in electronic circuits from damage by various surge pulses.
This fast response characteristic of TVS diodes allows them to play an important role in various electronic systems, especially where precision electronic components need to be protected from transient voltage impacts. For example, in the fields of computer systems, communication equipment, automotive electronics, household appliances, etc., TVS diodes are widely used to protect circuits from electrostatic discharge, surge voltage, and electromagnetic interference.
