热电一体修正实现超低温漂运放的理论研究

Study of the possibility to decrease the temperature drift by thermal electrical trimming

热电一体分析了运放差分输入级的工作，指出了形成失调的３种原因（即源于工艺局部起伏的电学不对称、源于自身功耗的内热学不对称和源于环境温度梯度的外热学不对称）是造成温漂的原因；建议把外热学不对称降低到忽略不计的匀温台封装结构，并通过数值模拟和理论分析得到了其匀温特性计算公式；提出了降低电学不对称和内热学不对称的热电一体修正方法，该方法通过在高温、低温的循环修正使之趋于零．对该方法的理论依据和适用范围也进行了讨论．

The performance of the differential input stage of an operational amplifier is studied thermal electrically. Three reasons resulting in offset are pointed out as electrical unbalance whose principal responsible factor is the local variation of base width, internal thermal unbalance decided by the device power dissipation distributio, and external thermal unbalance effected by the ambient temperature gradient. A speical structure, called UTP (Uniforming Temperature Platform) is proposed to decrease external thermal unbalance to the negligible extent. UTP is studied by analysis and simulation and its performance formula is presented. A thermal electrical trimming method is proposed. This convergent procedure decreases the electrical and internal thermal unbalance to the negligible extent in spite of their forming mechanism. The validation basis and suitability of proposed technique are also discussed.