An amplifier with adjustable gain including a plurality of differential amplifiers and an output stage circuit is provided. Each of the differential amplifiers has at least one differential pair, two current terminals of each of the differential pairs are coupled by a connection structure, and the connection structure provides a negative feedback resistance. The differential amplifiers commonly receive a differential input signal pair, and output terminals of the differential amplifiers are coupled together. The output stage circuit inverts a voltage on the output terminals of the differential amplifiers to generate an output voltage. A direct current gain of the amplifier with adjustable gain is determined by adjusting at least one of working numbers of the differential amplifiers and the differential pairs.

A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.

The present disclosure provides circuit and method embodiments for calibrating a signal of an integrated circuit. A programmable resistive element is coupled in series with a node of the integrated circuit, where at least part of the integrated circuit is formed in at least one front end of line (FEOL) device level. The programmable resistive element is formed in at least one back end of line (BEOL) wiring level, and the programmable resistive element is in a non-volatile resistive state that is variable across a plurality of non-volatile resistive states in response to a program signal applied to the programmable resistive element.

A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.

A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.

The present disclosure provides circuit and method embodiments for calibrating a signal of an integrated circuit. A programmable resistive element is coupled in series with a node of the integrated circuit, where at least part of the integrated circuit is formed in at least one front end of line (FEOL) device level. The programmable resistive element is formed in at least one back end of line (BEOL) wiring level, and the programmable resistive element is in a non-volatile resistive state that is variable across a plurality of non-volatile resistive states in response to a program signal applied to the programmable resistive element.