PTZTFTE251 Automotive Zener Diodes ROHM Semiconductor PTZTFTE251 Automotive Zener Diodes are 1000mW, AEC-Q101 qualified diodes intended for voltage regulation. The PTZTFTE251 feature high reliability and a small power mold type. The ROHM PTZTFTE251 Automotive Zener Diodes are offered in a DO-214AC package.