Toshiba has introduced a new family of Zener diodes designed to improve surge protection and reliability in power-line applications. The launch includes fifteen new devices under the CMZBxxA series, aimed at shielding semiconductor circuits from switching surges and prolonged overvoltage pulses in both industrial and consumer systems.
A Move Away from Mesa Structures
The CMZBxxA range replaces Toshiba’s earlier CMZBxx series, which used a mesa-style construction that is now reaching end of life. The new diodes use a planar structure where the PN junction is protected by an oxide layer. This change reduces reverse leakage current and improves device consistency, helping engineers achieve greater stability in sensitive power circuits.
The move to planar manufacturing reflects a broader trend across the semiconductor industry towards tighter process control and improved electrical precision. Toshiba has halved the Zener voltage tolerance from ±10% to ±5% and reduced reverse current from 10 microamps to just 0.5 microamps. These improvements provide designers with a more predictable and efficient component for power protection design.
Managing Long-Pulse Surges
Power-line surges often last longer than typical ESD transients. When relays or switching converters operate, they can generate pulses that persist for several milliseconds. Events like these can cause damage to downstream semiconductors if not properly managed. Toshiba’s new Zener diodes are engineered to absorb both short and long-duration surges, offering a level of protection that extends close to DC conditions.
This makes them well suited to applications where inductive or capacitive loads are frequently switched, ensuring that overvoltage stress does not compromise long-term reliability.
Seamless Upgrade and Broad Voltage Range
Each of the fifteen CMZBxxA diodes uses Toshiba’s compact M-FLAT package (2.4 mm × 4.7 mm × 0.98 mm), identical to the outgoing CMZBxx series. This allows existing designs to be upgraded without any PCB layout changes. The lineup covers Zener voltages from 12 V to 51 V, supporting a wide variety of power-supply configurations used in industrial and consumer electronics.
A Quiet but Crucial Role
Zener diodes rarely attract attention, yet they perform one of the most important functions in electronics: keeping power systems stable and protected. Toshiba’s introduction of a planar structure, improved voltage control, and lower leakage represents more than an incremental update. It is a practical enhancement that helps engineers design power systems with greater confidence, predictability, and resilience.
Learn more and read the original article on www.toshiba.semicon-storage.com
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