The LM1558 and the LM1458 are general purpose dual operational amplifiers. The two amplifiers share a common bias network and power supply leads. Otherwise, their operation is completely independent. The LM1458 is identical to the LM1558 except that the LM1458 has its specifications guaranteed over the temperature range from 0˚C to +70˚C instead of −55˚C to +125˚C.