Zener diodes provide precise voltage reference at lowest tolerance

Nexperia has claimed the industry’s first range of A-selection Zener diodes. The BZT52H-A (SOD123F) and BZX384-A (SOD323) series, with a tolerance of ±1%,  provides a higher precision voltage reference compared to the B (±2%) and C (±5%) variants. Also available as part of the Q-portfolio, these Zener diodes address increasing regulatory requirements and demands in mobile, portable/wearable, automotive, and industrial applications, said the company.

The A-selection Zener diodes offer a nominal working voltage range of 2.4 V to 75 V (E24 range). Key specifications include non-repetitive peak reverse power dissipation of ≤40 W, total power dissipation ≤250 mW, and low differential thermal resistance.

“Nexperia’s A-selection Zener diode range covers every application from 1.8 V to 75 V while providing a precise voltage reference with the lowest possible tolerance,” commented Paula Stümer, product manager at Nexperia, in the release.“ By replacing B- or C-selection devices with pad compatible A-selection Zener devices, engineers can go to the limits of the MOSFET, if applied to limit voltage for the gate-source path or drain-gate path, or choose from a wider variety of suitable MOSFETs.”

Nexperia also noted that the low tolerance, which provides a higher precision voltage, enables engineers to replace more expensive voltage reference devices. “Instead of protecting the MOSFET directly, a more cost-efficient alternative is to connect a Zener diode in parallel to the drain-gate path. Once the Zener breaks through, the MOSFET switches on to stop the drain-source from going into an avalanche breakdown.”

The A-selection Zener diodes, available as Q-portfolio devices, meet the AEC-Q101 and ISO/TS16949 automotive quality standards. However, more non-automotive applications are requiring additional quality-related services, such as PPAP (Production Part Approval Process) and extended longevity, said Nexperia.

Another difference between the standard and Q-portfolio devices is the Product Change Notifications (PCN) period, said the company, which is extended from 90 days, according to JEDEC requirements, to 180 days. All parts are supported with a minimum longevity of 10 years and come with a shelf-life of more than two years. The A-selection Zener diodes are available in samples and volume production quantities.