National semiconductor 1a negative low dropout voltage regulator lm2990 national semiconductor lm2990t 12 ldo negative voltage regulator 12v output voltage 0 6v dropout voltage single output 1 5a output current 5 voltage accuracy 26v to 0 3v supply voltage 40 to 125 c to 220 case three terminal regulator low dropout voltage low quiescent current national semiconductor lm2990t 12 voltage regulator 1 5a to220