IN Brief:
- TPSMA6L28A-AQ is a 28V unidirectional TVS diode rated for 600W peak pulse power.
- The AEC-Q101-qualified device uses an SMAF package approximately half the height of a conventional SMA package.
- Electrical limits include 31.1V minimum breakdown and 45.4V maximum clamping at a 13.3A peak pulse current.
Diotec Semiconductor has introduced a low-profile automotive transient-voltage suppressor rated for 600W peak pulse power, targeting vehicle electronics where protection components have to absorb supply disturbances without consuming the package height of a conventional SMA diode.
The TPSMA6L28A-AQ is a 28V unidirectional TVS device in an SMAF surface-mount package and is qualified to AEC-Q101. Diotec specifies a minimum breakdown voltage of 31.1V and maximum clamping voltage of 45.4V at a 13.3A peak pulse current, with maximum reverse leakage of 1µA at the rated stand-off voltage.
Diotec says the SMAF outline is approximately half the height of a conventional SMA package. The company is targeting automotive dashboards, infotainment hardware, air-conditioning controls, and other densely packaged electronics where vertical clearance and PCB area are constrained.
TVS diodes perform a deliberately simple function, but selecting one correctly requires more than matching the nominal supply voltage. During normal operation the device remains below its avalanche region and draws very little current. When the protected rail rises sufficiently, it begins conducting and diverts transient current in an attempt to hold the voltage seen by downstream electronics within a survivable range.
The electrical limits therefore have to be considered together. The stand-off rating must sit above the maximum normal supply level, breakdown has to begin before the protected circuit reaches an unsafe voltage, and the clamping voltage under surge current must remain compatible with the absolute maximum ratings of the electronics behind it.
For the TPSMA6L28A-AQ, the 28V stand-off rating is accompanied by a specified breakdown range of 31.1V to 34.4V at 1mA. Maximum clamping reaches 45.4V at 13.3A under the manufacturer’s test condition. Those values provide the load-line information required to determine whether the part is suitable for a specific power rail or protection architecture.
The headline 600W pulse figure requires similar care. Peak pulse power is defined for a specified transient waveform and thermal condition and should not be interpreted as a continuous dissipation rating. Wiring inductance, capacitor charging, load switching, and supply disturbances can produce substantially different pulse shapes, so the energy delivered to the device during the real event remains a design consideration.
Automotive qualification adds another layer because the suppressor has to retain predictable behaviour across temperature and product life. Diotec specifies a junction-temperature range from -50°C to 150°C and moisture-sensitivity level 1. AEC-Q101 qualification establishes the component-level automotive test framework, while the completed ECU still requires validation against the electrical and environmental requirements of the particular vehicle platform.
Reducing package height does not remove thermal constraints. Surge current is converted into heat in the silicon, and repetitive events or unusually long disturbances can exceed the assumptions behind a peak pulse specification. PCB copper, terminal temperature, ambient conditions, and event frequency all influence how much margin remains once the component is installed.
The distinction between supply protection and high-speed signal protection also matters. A TVS diode selected to absorb substantial power on a supply rail may present more capacitance than a device intended for a high-speed communication interface. Component choice therefore has to follow the node being protected rather than treating all transient suppressors as interchangeable.
The TPSMA6L28A-AQ is a modest component development, but it addresses a persistent packaging problem. Vehicle electronics continue to add displays, processors, connectivity, sensors, and local control functions while enclosures and PCB stack-ups remain tightly constrained. Protection devices cannot simply disappear to make space for those functions.
Putting a 600W-class suppressor into a lower-profile package gives designers another option where mechanical clearance is tight but substantial transient capability is still required. Whether it provides sufficient protection will depend on the actual disturbance, clamping margin, thermal path, and lifetime requirements of the ECU rather than the package reduction alone.