LM340T-12 电源IC LM340T-12,LM340T12 LM340T-12/7812 LM340T-12/NOPB LM340T-12/NOPB . LM340T-12/NOPB. LM340T-12+ LM340T12-7812 LM340T-12NOPB LM340T12P