An ultrasound power amplifier is a device that amplifies low-power signals to high-power signals, and is a key component for ultrasound imaging, treatment and inspection. It is mainly composed of power amplifier circuit, control circuit, protection circuit and other parts. This article will introduce the technical solution of ultrasonic power amplifier, including its basic principle, design process and precautions.
Fundamental
The basic principle of the ultrasonic power amplifier is to amplify the low-power signal from the ultrasonic generator through the power amplifier to make it reach enough power for medical imaging or treatment. The ultrasonic power amplifier adopts the amplification principle of electronic devices, amplifies the signal input terminal through a common source amplifier circuit, and then transmits the amplified signal to the ultrasonic transducer through the output transformer. The frequency of the ultrasonic power amplifier usually used is 20kHz~10MHz.
Design Flow
The design process of ultrasonic power amplifier is as follows:
(1) Determine the power requirement: It is necessary to determine the required power according to different application scenarios.
(2) Select the appropriate power tube: Select the appropriate power tube according to the power demand, usually IGBT, FET, etc.
(3) Design the power amplifier circuit: design the power amplifier circuit according to the selected power tube, including common source amplifier circuit, output transformer, etc.
(4) Design control circuit: The control circuit is mainly used to control the switching state and current of the power tube to ensure the normal operation of the power amplifier.
(5) Design protection circuit: In order to protect the power tube and ultrasonic transducer from damage, a suitable protection circuit needs to be set in the power amplifier.
(6) Carry out simulation: Carry out simulation, check and analyze the design, and optimize the performance of the power amplifier.
(7) Experimental verification: carry out experimental verification, debugging and optimization of the designed power amplifier.
Figure: ATA-3080 Power Amplifier Index Parameters
When designing an ultrasonic power amplifier, the following issues need to be paid attention to:
(1) Determine power requirements: Determine the required power according to the needs of different application scenarios.
(2) Select the appropriate power tube: Select the appropriate power tube according to the power demand, usually IGBT, FET, etc. can be selected.
(3) Design the power amplifier circuit: When designing the power amplifier circuit, it is necessary to pay attention to the parameters of the power tube, input signal, output load and other factors. For example, indicators such as gain, frequency response, and distortion rate need to be considered.
(4) Design control circuit: The control circuit is mainly used to control the switching state and current magnitude of the power tube, and a reasonable selection of devices and design solutions is required.
(5) Design protection circuit: For ultrasonic power amplifiers, overheating, overcurrent and other faults will cause equipment damage, so corresponding protection circuits need to be set. For example, over-temperature protection, over-current protection, etc. need to be considered.
(6) Perform simulation: When performing simulation, parameter optimization is required to meet the performance requirements of the power amplifier.
(7) Experimental verification: When carrying out experimental verification of the designed power amplifier, it is necessary to pay attention to safety issues, and carry out debugging and optimization.
The above is the content of the basic principle and design process of the ultrasonic power amplifier.