It is LM108 and LM112 (internally compensated) and there is really no trick there. It's got 1nA input bias which can be fairly secure with temperature as in most bipolar opamps because β actually increases with temperature. Afterwards iterations like LT1008/LT1012 or OP97 pushed it right down to ）是射频接收系统的核心器件，用于放大微弱信号并最小化噪声引入，其参数直接决定系统灵敏度、动... https://rivergdxrl.daneblogger.com/33260075/the-2-minute-rule-for-low-noise-amplifier