LM3940ISX-5.0 LM3940IT -3.3 LM3940IT3.3 LM3940IT-3.3 LM3940IT-3.3 P+ LM3940IT-3.3/NOPB LM3940IT-3.3/NOPB . LM3940IT-3.3/NOPB 稳压(齐纳)二极管 LM3940IT-3.3NOPB LM3940IT-3.3P