Standoff voltage
The highest voltage the device tolerates without conducting. Set it above the normal working voltage including ripple, or the part leaks in service.
Protective Component products
TVS Diodes and ESD Protection Devices
TVS diodes absorb surge energy; ESD devices clamp fast static discharges with very low capacitance. Both clamp, but they are sized for different events. Start from what you are protecting against, then match standoff voltage, clamping voltage and capacitance to the port.
Part number search & selector
Find TVS Diodes and ESD Protection Devices part numbers
The table uses the current English-site product records, published selection fields and part-specific technical-file links.
* Frozen Image and Part Number columns · drag horizontally to review all specifications
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Polarity
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Vesd Air/Vesd Contact
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Operating Temperature
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| Image | Part number | Datasheet | Compare | Downloads | Polarity | Vrwm/V | Vesd Air/Vesd Contact | Cj/pf | Package | Operating Temperature | Sample |
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WHALD03G4U | SPEC | ESD | 3.3 | ±15KV/±12KV | 0.3 | DFN2510-10L | -40 °C to 125 °C |
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WHALD30E2B | SPEC | Bi-Directional ESD | 30 | ±30KV/±30KV | 0.9 | SOT-23 | -40 °C to 125 °C |
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WHTA5V01P2C | SPEC | ESD | 5 | ±20KV/±20KV | 1.2 | SOT-363 | -40 °C to 125 °C |
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WHTB058VA | SPEC | Bi-Directional TVS | 58 | - | - | DO-214AB | -60 °C to 150 °C |
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WHTA3V30P8B | SPEC | ESD | 3.3 | ±30KV/±30KV | 0.8 | SOD323 | -40 °C to 125 °C |
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No matching part numbers
Broaden the selected filters or clear the current search.
By polarity
Unidirectional and bidirectional devices
Polarity follows the signal: unidirectional for DC rails, bidirectional for AC and differential lines.
How to select
Selecting a TVS or ESD device in four steps
Threat first, then polarity, then the voltage window, then capacitance.
- 01
Identify the threat
Surge energy from lightning or switching needs a TVS. Fast human-body or contact discharge on a data port needs a low capacitance ESD device.
- 02
Choose the polarity
Unidirectional suits single-polarity DC rails. Bidirectional suits AC lines and differential pairs that swing both sides of ground.
- 03
Set the voltage window
Standoff voltage above the highest normal working voltage, clamping voltage below what the protected device survives. Both have to hold.
- 04
Check capacitance
On high speed lines, capacitance decides whether the protection is usable. Measure the eye diagram and return loss after fitting.
Parameters
Reading TVS and ESD ratings
Standoff and clamping voltage form a window that both has to fit inside.
Breakdown voltage
Where conduction begins, measured at a small stated test current. It sits above the standoff figure and below the clamping voltage.
Clamping voltage
The voltage across the device while it diverts a stated peak current. This is what the protected circuit actually sees, so compare at the same current.
Peak pulse power
Energy handling at a stated waveform, commonly 8 by 20 or 10 by 1000 microseconds. The waveform must match or the figures do not compare.
Capacitance
The load the device places on the line. Low capacitance parts exist specifically so high speed signals are not degraded by the protection.
Polarity
Unidirectional conducts hard in one direction only. Bidirectional behaves symmetrically, which is required where the signal swings both ways.
Compare
TVS against ESD devices and other protection
Energy handling, response speed and capacitance separate the choices.
Return to the selector ↑| Polarity | Parts | Vrwm/V | Vesd Air/Vesd Contact | Cj/pf | Package | Operating Temperature | Action |
|---|---|---|---|---|---|---|---|
| Bi-Directional TVS | 1 | 58 | - | - | DO-214AB | -60 °C to 150 °C | Filter → |
| ESD | 3 | 3.3, 5 | ±15KV/±12KV, ±20KV/±20KV, ±30KV/±30KV | 0.3, 0.8, 1.2 | SOD323, SOT-363, DFN2510-10L | -40 °C to 125 °C | Filter → |
| Bi-Directional ESD | 1 | 30 | ±30KV/±30KV | 0.9 | SOT-23 | -40 °C to 125 °C | Filter → |
Application review
Where TVS and ESD devices are fitted
Confirm the port type, the standard to be met and the signal speed on that line.
USB and high speed data ports
- Capacitance decides usability here. Choose a low capacitance ESD part and verify the eye diagram and return loss after fitting.
Ethernet interfaces
- Confirm how the device interacts with the magnetics already in the path, then check the clamping figure against the transceiver rating.
DC power rails
- Unidirectional parts suit single polarity rails. Set standoff above worst-case rail voltage including ripple and transients.
Industrial and automotive buses
- Buses swing both sides of ground, so bidirectional parts are usually required. Confirm the common mode range the bus specifies.
Documents
TVS and ESD datasheets
Datasheets carry the clamping curve, pulse waveform conditions and capacitance.
Showing representative available file sets. Search to find a specific SKU.
WHALD03G4UESD
WHALD30E2BBi-Directional ESD
WHTA5V01P2CESD
WHTB058VABi-Directional TVS
WHTA3V30P8BESD
- 5
- PDF datasheets listed
- 0
- 3D file sets listed
- 0
- PCB footprints listed
VOOHU’s published product content is reviewed by its engineering team. Specifications, downloads and technical support information are tied to specific part numbers, so you can verify them before requesting samples or a quotation.
Category overview
TVS or ESD device, and which way round
Two decisions cover most of this category: which technology matches the threat, and whether the part needs to be unidirectional or bidirectional.
Discuss a new design
Contact FAE for a replacement assessment.
Already have a part number? Request samples or a quote.
Different events, different parts
A TVS diode is sized for surge energy from lightning coupling or heavy switching, rated in peak pulse power at a defined waveform. An ESD device is sized for fast, low energy static discharge and built for very low capacitance, so it can sit on a high speed line. Sizing one against the other threat gives the wrong part.
Polarity follows the signal
A unidirectional device conducts hard one way and blocks the other, which suits a DC rail that never goes negative. A bidirectional device is symmetric, which AC lines, differential pairs and buses swinging both sides of ground require. Fit a unidirectional part there and it conducts on the negative half.
Capacitance is the limit on fast lines
The device sits in parallel with the signal, so its capacitance is a load the line has to drive. On a high speed pair, a few picofarads visibly degrades the eye and raises return loss. That is why low capacitance ESD parts are a separate category, and why the eye should be measured with the part fitted.
FAQ
TVS and ESD questions engineers ask
Answers cover TVS against ESD, polarity choice, capacitance and placement.
What is the difference between a TVS diode and an ESD device?
A TVS diode is sized for surge energy from lightning coupling or heavy switching, rated in peak pulse power at a defined waveform. An ESD device handles fast, low energy static discharge and is built for very low capacitance so it can sit on a high speed line. Both clamp, but they are sized against different events.
When do I need a bidirectional device?
Whenever the protected line swings both sides of ground: AC lines, differential pairs and most buses. A unidirectional part conducts hard on the negative half cycle and corrupts the signal. Unidirectional parts suit DC rails that never go negative in normal operation.
How do I set the standoff voltage?
Above the highest voltage the line reaches in normal service, including ripple and any transients that are not faults. Too low and the part leaks or conducts during operation. Then check the clamping voltage at your actual surge current still sits below what the protected device survives.
Why does capacitance matter so much?
The device sits in parallel with the signal, so its capacitance loads the line. On a high speed pair even a few picofarads visibly degrades the eye and raises return loss. That is why low capacitance ESD parts exist as a separate category, and why you should measure the eye with the part fitted.
Where should the protection device be placed?
As close to the connector as the layout allows, so the discharge is diverted before it reaches the rest of the board, with a short wide path to ground. The signal should not pass the protected chip first and then reach the device. Stray inductance in the ground path adds overshoot.
Can I use a TVS instead of an ESD device on a data line?
Only if its capacitance is low enough for the data rate. A general purpose TVS sized for surge energy usually has capacitance high enough to degrade a fast link noticeably. Check the capacitance against your line, and if in doubt measure the eye diagram both ways.
Do I still need protection if the port has magnetics?
Often yes. Magnetics provide isolation and some common mode rejection but are not a substitute for a clamp against fast transients. Whether additional protection is needed depends on the standard you must meet and on your layout, so confirm against the requirement rather than assuming.
How do I request TVS or ESD samples or a quote?
With a complete part number, send the part number, quantity, delivery region and the date you need it. If you are still selecting, send the port type, the normal working voltage, the standard and level you must meet and the data rate on that line.
Engineer support
Continue after product selection
Send the candidate part number and the condition you need reviewed. Sample support can be added after the selection is clear; commercial questions may be discussed in the same engineering conversation.
- 1Selected part numbers
- 2Engineering review
- 3Sample request
- 4Commercial discussion
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Sample quantity, lead time and cost depend on the project stage and part number. Sales will respond on business days.
Published replacement reviews
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