The output stage of an operational amplifier on GaAs n-channel field-effect and GaAs p-n-p bipolar transistors with nonlinear negative feedback

<p>A new circuit of the output stage of an operational amplifier implemented on GaAs n-channel field-effect transistors with a control p-n junction and GaAs bipolar p-n-p transistors is investigated. Its peculiarity consists in the presence of a nonlinear negative feedback that stabilizes the drain current of the output transistor with an n-channel at a negative input voltage. The basic equations for the static mode of the output stage are given. The results of modeling in the LTspice simulation software of 3 modifications of the proposed circuit solutions are discussed.</p>

The output stage of an operational amplifier on GaAs n-channel field-effect and GaAs p-n-p bipolar transistors with nonlinear negative feedback

<p>A new circuit of the output stage of an operational amplifier implemented on GaAs n-channel field-effect transistors with a control p-n junction and GaAs bipolar p-n-p transistors is investigated. Its peculiarity consists in the presence of a nonlinear negative feedback that stabilizes the drain current of the output transistor with an n-channel at a negative input voltage. The basic equations for the static mode of the output stage are given. The results of modeling in the LTspice simulation software of 3 modifications of the proposed circuit solutions are discussed.</p>

α-spectrum estimation for 1/f processes in noisy environments

In the past, 1/ f noise was regarded as a stochastic process that accords with Gaussian distribution. According to our studies, the output transistor 1/ f noise can be characterized more accurately as non-Gaussian α-stable distribution rather than Gaussian distribution. We define and consistently estimate the samples normalized cross-correlations of linear S αS processes and propose a samples normalized cross-correlations–based α-spectrum method effective in noisy environments. Simulation results and diodes noise spectrum estimation results exhibit good performance.

Analysis Approach on DMOS Transistor Vth Mismatch Due to Trapped Charges

An output switching malfunction was reported on a bridge driver IC. The electrical verification testing revealed evidence of an earlier over current condition resulting from an abnormal voltage sense during a switching event. Based on these test results, we developed the hypothesis that a threshold voltage mismatch existed between the sense transistor and the output transistor. This paper describes the failure analysis approach we used to characterize the threshold voltage mismatch as well as our approach to determine the root cause, which was trapped charge on the gate oxide of the sense transistor.