FET amplifier

About: FET amplifier is a research topic. Over the lifetime, 7048 publications have been published within this topic receiving 77549 citations.

Two-stage amplifier for active pixel sensor cell array for reducing fixed pattern noise in the array output

Abstract: An active pixel sensor cell array in which a two-stage amplifier amplifies the output of each cell. The two-stage amplifier design reduces fixed pattern noise in the image data generated by reading the array, by providing increased gain for the output of each cell without impractically increasing the size and complexity of each cell. For each column of cells of the array, one part of the two-stage amplifier for each cell is shared by all cells of the column, and another part of the two-stage amplifier for each cell is included within the cell itself. Preferably, each cell includes only NMOS transistors (no cell includes a PMOS transistor). In preferred embodiments, a differential amplifier within each cell is the primary stage of the cell's output amplifier, PMOS load circuitry including a secondary output amplifier stage is shared by all cells of the column, and the two amplifier stages for each cell together comprise an op amp. In some such preferred embodiments, the op amp is provided with capacitor feedback for increased gain. Another aspect of the invention is an active pixel sensor cell including a differential amplifier, and PMOS transistor load circuitry coupled to the cell. Preferably, the differential amplifier is the first stage of an op amp, and the remainder of the op amp, including optional capacitor feedback circuitry, is coupled to the cell but is not included within the cell.

Common-mode feedback circuit with differential-difference amplifier

Abstract: A common-mode feedback circuit suitable for fully balanced analog MOS structure realization is discussed. A novel scheme of differential-difference amplifier, the concept of which can be employed in CMFB system, is proposed. A transconductance amplifier is shown as an application example. SPICE simulation is used to verify the theory. >

Feedback cascode amplifier

Abstract: A microwave-frequency feedback amplifier circuit has a cascode amplifier with a first field-effect transistor (FET) having a gate for receiving a signal to be amplified, a source coupled to a reference voltage, and a drain. A second FET has a source coupled to the drain of the first FET, a source coupled to the reference voltage, and a drain. A transformer includes a first inductor with a first terminal coupled to the drain of the second FET and a second terminal for outputting an amplified input signal. A second inductor has a first terminal coupled to the second terminal of the first inductor, and a second terminal coupled to the reference voltage. A feedback circuit couples the drain of the second FET to the gate of the first FET.

On the choice of optimum FET size in wide-band transimpedance amplifiers

Abstract: The main figure of merit for transimpedance amplifiers used in amplifying photocurrents in fiber-optics systems is the optical sensitivity. This sensitivity is determined by the equivalent input noise current of the amplifier. To obtain the best noise performance, most transimpedance amplifiers with FET input stages are designed using a result that prescribes making the capacitance of the input FET equal to the photodiode capacitance. It is shown that this is not necessarily the most favorable practice when using FETs in scaled submicrometer technologies. For example, it may compromise the stability of the amplifier. >

RF power amplifier circuitry and method for amplifying signals

Abstract: An RF power amplifier is provided for use with wireless transmission systems such as cellular phones. An RF power amplifier includes direct drive amplifier circuitry operating in a push-pull scheme. The RF power amplifier includes a pair of switching devices driven by a pair of mutually coupled inductive devices. The inductive devices may be magnetically or capacitively coupled together. The RF power amplifier may be formed on a single integrated circuit and include an on-chip bypass capacitor. The RF power amplifier may utilize a voltage regulator for providing a regulated voltage source. The RF power amplifier may be provided using a dual oxide gate device resulting in an improved amplifier. The RF power amplifier may be packaged using flip chip technology and multi-layer ceramic chip carrier technology.