关键词: 跨导运算放大器（OTA）, 平方电路, 线性可调, 跨导增益, 滤波器, 神经网络, 现场可编程模拟阵列（FPAA）

Abstract: In order to solve the problems of the basic differential OTA, which has the limited input ranges, narrow tunable ranges and inability to linearly tune the transconductance gain, a new CMOS Operational Transconductance Amplifier（OTA） called LOTA is proposed, of which the transconductance gain can be widely and linearly tuned. The design method is achieved by employing two square circuits for bias of two basic differential CMOS OTAs respectively. By setting a reasonable reference current, not only the input voltage swing and the adjusting range of the gain can get a wide value at the same time, but also the transconductance gain can be continuously and linearly adjusted from a negative value to a positive one through the external bias currents. The proposed LOTA is employed to implement a second-order universal current-mode filter as an application. The performance of the LOTA and the filter is verified through PSPICE simulation results.

Key words: Operational Transconductance Amplifier（OTA）, square circuit, linearly tunable, transconductance gain, filter, neural network, Field Programmable Analog Array（FPAA）