The present application is based on, and claims priority from JP Application Serial Number 2019-236568, filed Dec. 26, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a liquid ejecting apparatus, a drive circuit, and an integrated circuit.

2. Related Art

As an example of a liquid ejecting apparatus that ejects a liquid such as ink to print an image or a document, ink jet printers that use a piezoelectric element such as a piezo element are known. Such a piezoelectric element is provided corresponding to a plurality of nozzles for ejecting ink in a print head. Then, the liquid ejecting apparatus including the piezoelectric element ejects a predetermined amount of ink from the nozzle corresponding to the piezoelectric element at a predetermined timing by operating the piezoelectric element according to a drive signal. As a result, the liquid ejecting apparatus forms dots of any size at any position of a medium.

JP-A-2019-162843 discloses a drive circuit (a drive signal generation circuit) and a liquid ejecting apparatus including the drive circuit, in which the drive circuit outputs a drive signal for operating a piezoelectric element that is a capacitive load, and includes an integrated circuit including a modulation circuit that modulates a base drive signal that is the basis of the drive signal, and an output circuit that outputs the drive signal based on an output from the integrated circuit.

The integrated circuit in the drive circuit described in JP-A-2019-162843 includes, in addition to the circuit for generating the drive signal for driving the piezoelectric element, a discharge circuit that discharges a charge based on the drive signal in order to protect the piezoelectric element and an ejection portion including the piezoelectric element. In the integrated circuit having such a plurality of functions, malfunction may occur depending on the arrangement of each circuit and terminal. However, since the liquid ejecting apparatus described in JP-A-2019-162843 does not disclose the arrangement of each circuit or terminal inside the integrated circuit in the drive circuit, there is room for improvement in terms of the circuit arrangement inside the integrated circuit for stabilizing the operation of the integrated circuit.

SUMMARY

According to an aspect of the present disclosure, there is provided a liquid ejecting apparatus including a liquid ejecting head having a drive element, and ejecting a liquid by supplying a drive signal to the drive element, and a drive circuit that outputs the drive signal. The drive circuit includes an integrated circuit that outputs an amplification control signal based on a base drive signal, an amplifier circuit that operates according to the amplification control signal to output an amplified modulation signal, and a demodulation circuit that demodulates the amplified modulation signal to output the drive signal. The integrated circuit includes a modulation circuit that modulates the base drive signal to output a modulation signal, a switching circuit that outputs the amplification control signal according to the modulation signal, a discharge circuit that discharges a charge based on the drive signal, a constant voltage output circuit that outputs a DC voltage signal, and an output terminal from which the DC voltage signal is output. The constant voltage output circuit and the discharge circuit are electrically coupled to the output terminal, and a shortest distance between the output terminal and the constant voltage output circuit is shorter than a shortest distance between the output terminal and the discharge circuit.

According to another aspect of the present disclosure, there is provided a drive circuit that outputs a drive signal for driving a capacitive load. The drive circuit includes an integrated circuit that outputs an amplification control signal based on a base drive signal, an amplifier circuit that operates according to the amplification control signal to output an amplified modulation signal, and a demodulation circuit that demodulates the amplified modulation signal to output the drive signal. The integrated circuit includes a modulation circuit that modulates the base drive signal to output a modulation signal, a switching circuit that outputs the amplification control signal according to the modulation signal, a discharge circuit that discharges a charge based on the drive signal, a constant voltage output circuit that outputs a DC voltage signal, and an output terminal from which the DC voltage signal is output. The constant voltage output circuit and the discharge circuit are electrically coupled to the output terminal, and a shortest distance between the output terminal and the constant voltage output circuit is shorter than a shortest distance between the output terminal and the discharge circuit.

According to still another aspect of the present disclosure, there is provided an integrated circuit used in a drive circuit that outputs a drive signal for driving a capacitive load. The integrated circuit includes a modulation circuit that modulates a base drive signal to output a modulation signal, a switching circuit that outputs an amplification control signal according to the modulation signal, a discharge circuit that discharges a charge based on the drive signal, a constant voltage output circuit that outputs a DC voltage signal, and an output terminal from which the DC voltage signal is output. The constant voltage output circuit and the discharge circuit are electrically coupled to the output terminal, and a shortest distance between the output terminal and the constant voltage output circuit is shorter than a shortest distance between the output terminal and the discharge circuit.

