High voltage power amplifier is a very general test instrument, with the manufacturer’s arbitrary wave signal generator to use, to enhance its driving ability, to ensure the purpose of driving the corresponding test equipment. Antai’s high-voltage power amplifier is widely used in MEMS testing, ultrasonic testing, piezoelectric ceramic drive, sonar system applications, etc., and is favored by universities, research institutes and laboratories.

How to choose a suitable power amplifier, what should be paid attention to

How to choose a suitable power amplifier? The following indicators should be noted:

1. Bandwidth

Bandwidth: generally, the bandwidth of amplifier is defined by sine wave. For example, 100kHz power amplifier refers to the highest frequency of sine wave signal, not square wave or triangular wave. These waveforms can not be achieved due to the influence of higher harmonics. Usually, the manufacturer will give small signal bandwidth or large signal bandwidth. Customers need to choose their own application and factory Communicate at home.

2. Voltage

Voltage: the highest voltage value that needs to amplify the signal. Customers usually need to pay attention to whether the voltage required for their own test application is the effective value VRMs or peak to peak VPP. Usually, the manufacturer gives the peak to peak value.

3. Current

Current: the output power of a power amplifier is usually constant, so p = u * I, that is, the voltage and current are inversely proportional under constant power. Generally, the current value given by the manufacturer is the maximum, especially when the voltage output is the maximum under DC, the current must be the minimum.

4. Power

Power: power represents the driving capacity of the amplifier, P = u * I. generally, the selection of power is related to the voltage and current that the customer expects to load on the equipment to be tested. However, if the load is purely resistive, it is convenient to calculate. If it is capacitive or inductive, the customer needs to communicate with the manufacturer’s engineer to obtain an accurate demand after certain simulation.

5. Access

Channel: select the number of channels according to the test application. At present, the mainstream of manufacturers is single channel or dual channel, but some manufacturers can customize channels according to the user’s needs, up to 8 channels. At the same time, it can ensure the synchronization of channels and output signals with different phase differences, which is convenient for users.

6. Gain

Gain: it is divided into analog gain and numerical control gain. The analog gain is adjusted by potentiometer. The analog gain can not be accurately amplified, but can only be read by external observation oscilloscope. It is gradually eliminated by manufacturers. Digital gain control has high adjustment accuracy and is intuitive and convenient. It is the current gain amplification method adopted by mainstream amplifiers.

7. Input and output impedance matching

Input and output impedance matching: the amplifier is usually used with the signal source, usually the signal source has 50 ohm and high resistance output, and the amplifier has corresponding matching impedance in the input impedance to ensure the safety of the input end. Output impedance matching, due to the diversity of customer driven loads, manufacturers need to provide more flexible matching resistance.

8. Protection

Protection: because the power amplifier drives the load and many of them are dynamic, it puts forward higher requirements for the power amplifier. In order to prevent damage to the power amplifier, it usually requires overvoltage protection, overcurrent protection, overheat protection and short circuit protection.


Because the power amplifier usually drives the load, and the complex characteristics of the load determine the risk of using the power amplifier

1. Select the appropriate power amplifier, and estimate the voltage, current, power, frequency and waveform of the input signal (see how to select the power amplifier).

2. Ensure safe grounding of power amplifier

3. Check the manual to see if the corresponding products of the manufacturer support long-time continuous working ability

4. Pay attention to the heat dissipation of the instrument

5. The stability and reliability of the front-end connecting line can prevent the occurrence of short circuit

6. The input signal of signal source is within the safe range

Editor in charge: GT

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