LM112/LM212/LM312 Operational Amplifiers General Description The LM112 series are micropower operational amplifiers with very low offset-voltage and input-current errorsÐat least a factor of ten better than FET amplifiers over a b55§C to a125§C temperature range. Similar to the LM108 series, that also use supergain transistors, they differ in that they include internal frequency compensation and have provisions for offset adjustment with a single potentiometer. These amplifiers will operate on supply voltages of g2V to g20V, drawing a quiescent current of only 300 mA. Performance is not appreciably affected over this range of voltages, so operation from unregulated power sources is easily accomplished. They can also be run from a single supply like the 5V used for digital circuits. The LM112 series are the first IC amplifiers to improve reliability by including overvoltage protection for the MOS compensation capacitor. Without this feature, IC's have been known to suffer catastrophic failure caused by short-duration overvoltage spikes on the supplies. Unlike other internally- compensated IC amplifiers, it is possible to overcompensate with an external capacitor to increase stability margin. The LM212 is identical to the LM112, except that the LM212 has its performance guaranteed over a b25§C to a85§C temperature range instead of b55§C to a125§C. The LM312 is guaranteed over a 0§C to a70§C temperature range. Features Y Maximum input bias current of 3 nA over temperature Y Offset current less than 400 pA over temperature Y Low noise Y Guaranteed drift specifications