Bourns has introduced the PTVS03-450E-H, a unidirectional power TVS diode for transient overvoltage protection in DC bus circuits.
The TVS diode for transient overvoltage protection combines a 450 V repetitive standoff voltage with a 300 A peak surge-current rating for an 8/20 µs waveform in a surface-mount DFN package. Its selection hinges on the voltage across the protection node during normal operation and the residual voltage during a surge.
Key features and benefits
- 450 V repetitive standoff voltage, with standby current of 10 µA maximum at that voltage.
- 300 A peak surge-current capability for the IEC 61000-4-5 8/20 µs current waveform.
- Maximum clamping voltage of 680 V at 300 A with an 8/20 µs pulse.
- Unidirectional operation for DC bus clamping.
- DFN package with nominal dimensions of 10.00 × 8.00 × 2.50 mm.
- Operating junction temperature range of −55 °C to +150 °C.
- Moisture sensitivity level 1 and RoHS compliance.
Technical highlights
Working voltage, breakdown and clamping
The clamping voltage determines the transient voltage across the device while it carries surge current. It is distinct from both the 450 V repetitive standoff voltage and the breakdown voltage measured at 10 mA.
| Parameter | Value | Conditions |
|---|---|---|
| Repetitive standoff voltage | 450 V | Ambient 25 °C |
| Peak surge current | 300 A | 8/20 µs |
| Breakdown voltage | 455–500 V | 10 mA |
| Typical breakdown voltage | 480 V | 10 mA |
| Maximum standby current | 10 µA | Applied voltage 450 V |
| Breakdown-voltage temperature coefficient | 0.1%/°C | Typical |
| Operating junction temperature | −55 °C to +150 °C | Junction |
| Storage temperature | −55 °C to +150 °C | Unpowered |
Electrical characteristics apply at an ambient temperature of 25 °C unless otherwise noted. The breakdown-voltage temperature coefficient makes temperature part of the protection-window assessment: the room-temperature breakdown value is not a fixed threshold across the operating range.
Clamping depends on current and waveform
The PTVS03-450E-H has separate clamping limits for 8/20 µs and 2/10 µs pulses. At the same peak current, the two waveforms produce different voltage limits.
| Peak pulse current | Maximum clamp, 8/20 µs | Maximum clamp, 2/10 µs |
|---|---|---|
| 50 A | 550 V | 540 V |
| 100 A | 600 V | 570 V |
| 200 A | 640 V | 610 V |
| 300 A | 680 V | 640 V |
These clamping voltages are measured at the instant of peak surge current. Protection design should therefore use the value corresponding to the required current and waveform, rather than treating the device as a fixed-voltage clamp.
The 300 A rating is a pulse-current limit, not a continuous-current rating. Surge-current capability also depends on ambient temperature; the temperature-derating curve belongs in the selection process alongside the electrical limits.
Package and assembly
The surface-mount DFN body measures 10.00 ± 0.10 mm by 8.00 ± 0.10 mm, with a height of 2.50 ± 0.10 mm. A cathode band provides polarity identification.
The molded package has 100% tin terminations and a UL 94 V-0 flammability rating. The device has UL agency recognition under file E215609. Tape-and-reel packaging contains 1,700 pieces per reel.
Typical applications
Target applications include:
- DC bus protection.
- 800 V DC distribution architectures, including AI deployment and rack protection.
- Solid-state circuit breakers.
For DC bus clamping, the 450 V standoff rating governs the normal voltage across the device. During an 8/20 µs surge, the maximum clamp rises from 550 V at 50 A to 680 V at 300 A, setting the voltage range that the protected circuit must accommodate.
Application fit
An 800 V distribution architecture and a 450 V TVS working voltage refer to different selection levels: the system architecture does not determine the voltage across an individual protection component. The PTVS03-450E-H must be applied at a circuit position where its repetitive standoff limit is respected; it is not a single-device clamp to connect directly across a continuously energized 800 V rail.
In solid-state circuit breakers, the relevant selection parameters are the voltage across the clamp, the peak pulse current and the resulting clamping voltage. The TVS handles transient voltage stress; its 300 A surge rating does not define the breaker’s continuous load-current capability.
Interconnection inductance also contributes to the voltage experienced by the protected circuit. A surface-mount package does not eliminate that contribution, so the surge-current path and its return should remain short.
Design-in notes for engineers
- Keep the maximum normal voltage across the device within its 450 V repetitive standoff rating, including operating tolerances and legitimate voltage excursions.
- Compare the protected circuit’s transient-voltage limit with the clamping value at the required pulse current and waveform.
- Include temperature-dependent breakdown behaviour and surge-current derating in the protection assessment.
- Use the recommended footprint and cathode orientation when creating the PCB land pattern.
- Minimise inductance in the surge-current path and return; assess the voltage at the protected circuit as well as across the TVS.
- Validate final selection under the actual operating conditions before production release.
Further reading
Source
This article is based on the Bourns product announcement and official product documentation. Engineers should refer to the current manufacturer datasheet for final design and qualification.
References
- PTVS03-450E-H Power TVS Diode, Bourns, revision October 2026.
- Bourns Introduces Model PTVS03-450E-H Power TVS Diode, Bourns, October 26, 2026.
- Surface Mount Power TVS Diodes Deliver Optimal Protection for Power Supplies, Bourns, April 2017.
