A negative impedance circuit includes: a differential circuit stage; a positive feedback path from an output of the differential circuit stage to a first input of the differential circuit stage; and a negative feedback path from the output of the differential circuit stage to a second input of the differential circuit stage. The negative feedback path includes a first transistor, and a unitary gain path from the output of the differential circuit stage to the second input of the differential circuit stage, the unitary gain path coupled to ground via a reference impedance. The positive feedback path includes a second transistor. The first and second transistors are coupled in a current mirror arrangement and have respective control electrodes configured to be driven by the output of the differential circuit stage, where the negative impedance circuit causes a negative impedance at the first input of the differential circuit stage.

An operational amplifier includes a pre-amplifier circuit, a first trim circuit, and a second trim circuit. The pre-amplifier circuit is to include a differential pair and receive an input voltage. The first trim circuit is to produce an offset voltage correction current and provide the offset voltage correction current to the pre-amplifier circuit to correct an offset of the operational amplifier. The second trim circuit is to produce a common mode voltage (VCM) correction current, provide the VCM voltage correction current to the pre-amplifier circuit, and cause the VCM correction current to have a non-zero value to reduce a correction caused by the offset voltage correction current when the input voltage is within a mid voltage input range. The pre-amplifier circuit is to apply the offset correction current and the VCM correction current to output signals of the differential pair.

The present invention relates to an operational amplifier, including: a symmetrical differential amplifier; a local common mode feedback circuit coupled to the symmetrical differential amplifier; a tail current source circuit including at least one first transistor and a second transistor and a current source resistor. The tail current source circuit is configured to adjust a control voltage of the first transistor by using the second transistor such that a predetermined reference current flows through a load path of the first transistor.

A differential amplifier of a memory controller may include: an amplification stage configured to amplify input differential signals to generate intermediate differential signals; a control circuit configured to control slew rates for the intermediate differential signals; and an output circuit configured to selectively perform one or more switching operations according to the intermediate differential signals to generate output differential signals.

Cross-coupling of switched-capacitor output common-mode feedback capacitors in dynamic residue amplifiers is provided via a cross-coupled amplifier, comprising: a current source connected to a first node; a feedback capacitor connected to the first node and a second node; a feedback resistor connected between the second node and ground; an amplifier having an input connected to the second node; a gain transistor having: a drain connected to the first node; a source connected to ground; and a gate connected to an output of the amplifier; and a load capacitor connected to the first node and ground.

An amplifier circuit comprises a first amplifier circuit stage including input devices connected to inputs of the amplifier circuit, a second amplifier circuit stage coupled to the first amplifier stage, a common mode extraction circuit configured to extract a DC common mode voltage of the first amplifier stage, and a bias circuit configured to bias one or more output devices of the second amplifier circuit stage using the DC common mode voltage.

According to one embodiment, a constant voltage circuit includes: a first gain stage configured to output a first voltage amplified based on an output voltage and a reference voltage; a first transistor configured to control the output voltage based on the first voltage; a second transistor configured to control a current that flows through the first gain stage; a first circuit configured to convert an amount of fluctuation in the output voltage into a first current; and a second circuit configured to control a gate voltage of the second transistor based on the first current. A third current or a fourth current greater than the third current flows through the first gain stage based on the gate voltage of the second transistor.

Provided is an imaging apparatus including an imaging unit having a plurality of pixels, the pixels each having: a conversion element converting incident light into photoelectrons; a floating diffusion layer electrically connected to the conversion element and converting the photoelectrons into a voltage signal; a differential amplifier circuit electrically connected to the floating diffusion layer, including an amplifier transistor to which a potential of the floating diffusion layer is input, and amplifying the potential of the floating diffusion layer; a feedback transistor electrically connected to the amplifier transistor and initializing the differential amplifier circuit; a clamp capacitance connected in series between the floating diffusion layer and the amplifier transistor; and a reset transistor connected in parallel between the floating diffusion layer and the clamp capacitance and initializing the potential of the floating diffusion layer.

An automatic gain control circuit includes a linear-to-log conversion circuit, a current amplifier circuit, and an amplitude sense circuit. The current amplifier circuit includes a current input terminal coupled to an output terminal of the linear-to-log conversion circuit. The amplitude sense circuit includes an input terminal coupled to an output terminal of the current amplifier circuit, and an output terminal coupled to a gain control input terminal of the current amplifier circuit.

A digital transmitter architecture is disclosed to transmit (TX) multi-gigabit per second data signals on single carriers (SC) or orthogonal frequency division multiplexing (OFDM) carriers at millimeter wave frequencies in either one of a high-resolution modulation mode or a spectral shaping mode. The architecture includes a number of digital power amplifier (DPA) and modulation reconfigurable circuit segments to process individual bits of a data bit stream in parallel according to a specific circuit configuration corresponding to the selected TX mode using a multiplexer to switch between configurations.