A first switching circuit, a second switching circuit, a first bootstrap circuit that is coupled to the first switching circuit and the second switching circuit, and a smoothing circuit and outputs a drive signal are provided, in which the second switching circuit includes a second gate driver that outputs a third gate signal and a fourth gate signal, a third transistor of which the first voltage is supplied, and which is driven based on the third gate signal, a fourth transistor which is driven based on the fourth gate signal, and a second bootstrap circuit that includes a second capacitive element supplying a third voltage to the second gate driver and coupled to a second output point and the second gate driver, and a second diode of which the first voltage is supplied and which is coupled to the second capacitive element.

There are provided a substrate on which a first integrated circuit, a first transistor, a second integrated circuit, and a second transistor are disposed; a heat sink fixed to the substrate; the substrate has a first fixing reference hole and a second fixing reference hole, the heat sink has a first fixing reference pin and a second fixing reference pin which are inserted into the first fixing reference hole and the second fixing reference hole, and the first integrated circuit, the second integrated circuit, the first transistor, and the second transistor are positioned between the first fixing reference hole and the second fixing reference hole.

A liquid ejecting apparatus includes a head unit that ejects liquid, in which the head unit includes an integrated circuit and an ejector, the integrated circuit includes a drive signal input terminal that inputs a first drive signal, a first signal input terminal that inputs a first signal, a second signal input terminal that inputs a second signal, a first reference voltage signal input terminal that inputs a first reference voltage signal, a differential signal receiving circuit that converts a pair of first differential signals into a control signal and outputs the control signal, a drive signal selection circuit that outputs a second drive signal based on the control signal and the first drive signal, and a drive signal output terminal that outputs the second drive signal to the ejector, and the first signal input terminal and the first reference voltage signal input terminal are located adjacent to each other.

An liquid ejecting apparatus includes a drive signal output circuit, a control signal output circuit, a differential signal output circuit, a residual vibration signal input circuit, and a head unit, in which the head unit includes an integrated circuit and an ejector, and the integrated circuit includes a drive signal input terminal that inputs a first drive signal, a residual vibration signal output terminal that outputs a residual vibration signal, a differential signal receiving circuit that converts a pair of differential signals into a control signal and outputs the control signal, a drive signal selection circuit that outputs a second drive signal based on the control signal and the first drive signal, a drive signal output terminal that outputs the second drive signal to the ejector, and a residual vibration signal output circuit that outputs a residual vibration signal based on the residual vibration generated by driving the piezoelectric element.

A liquid discharge apparatus includes: a first discharge section that has a first piezoelectric element and discharges liquid by driving the first piezoelectric element with a driving signal; a driving signal generation section that generates the driving signal; a first selection section that performs a selection operation of selecting whether or not to apply each voltage of a plurality of driving waveforms included in the driving signal to the first piezoelectric element, based on a print data signal; a residual vibration detection section that detects residual vibration of the first discharge section after a voltage of a first driving waveform among the plurality of driving waveforms is applied to the first piezoelectric element; and a control section that generates the print data signal, in which the control section stops the driving signal generation section when causing the residual vibration detection section to detect the residual vibration.

A print head that includes a drive element to be driven when a drive signal is supplied to the drive element and that ejects liquid by the driving of the drive element includes an ejecting module including the drive element and a nozzle from which the liquid is ejected, and a current detecting circuit that detects a drive current generated due to propagation of the drive signal. The current detecting circuit includes a current detector that detects the drive current as a current detection signal, and a processor that controls an operation of the current detecting circuit according to the current detection signal.

A liquid ejecting apparatus includes a first pressure chamber communicating with a first nozzle configured to eject a liquid, a second pressure chamber adjacent to the first pressure chamber and communicating with a second nozzle configured to eject the liquid, and a first driving element corresponding to the first pressure chamber. The liquid ejecting apparatus executes a detection operation of detecting a fluctuation in the pressure of the liquid within the second pressure chamber that occurred when the first driving element was driven to cause the pressure of the liquid within the first pressure chamber to fluctuate.

A liquid ejecting apparatus includes a print head that includes a first terminal and a second terminal, a first circuit substrate electrically coupled to the print head, and a second circuit substrate electrically coupled to the first circuit substrate, wherein the first circuit substrate includes a first coupling terminal electrically coupled to the print head, and a first electrolytic capacitor, wherein the second circuit substrate includes a constant voltage output circuit that outputs a constant voltage signal supplied to the second terminal, a first output terminal that is electrically coupled to the first circuit substrate, and a second output terminal that is electrically coupled to the first circuit substrate, and through which the constant voltage signal is output to the first circuit substrate, wherein the first electrolytic capacitor is electrically coupled to the second output terminal and the first coupling terminal.

A liquid ejection apparatus includes an ejection head including a drive element driven by a drive signal and ejecting a liquid by driving the drive element, an ejection control circuit including a drive circuit that outputs the drive signal based on a base drive signal including a plurality of pieces of drive data, a main control circuit that outputs an ejection control signal including the base drive signal to the ejection control circuit, and a cable that communicably couples the ejection control circuit and the main control circuit and through which the ejection control signal propagates, wherein the ejection control signal includes the base drive signal and a determination signal corresponding to the base drive signal.

A liquid ejecting apparatus includes a driven element that is driven by a drive signal; an ejection head that ejects a liquid when the driven element is driven; a drive circuit that outputs the drive signal, the drive circuit including an amplifier circuit that includes a first transistor and amplifies, based on an amplification voltage and through an operation of the first transistor, a base drive signal based on which the drive signal is generated; and a leakage current detection circuit that detects a leakage current in the drive circuit. The leakage current detection circuit is electrically connected to the first transistor included in the amplifier circuit to which the amplification voltage is supplied.