What is low frequency power amplifier circuit?
Because of the power is equal to the product of voltage and current, so the small signal amplifier either amplifies the voltage signal or amplifies the current signal or the total signal power should be increased.
The main difference between the power amplifier circuit and the small signal amplification circuit is that the core components ( active devices ) of the amplifier circuit lose the signal amplitude, when designing the circuit, we try to make the signal full of the whole possible dynamic range, and the main consideration is not distortion, but also the energy conversion efficiency and the most large output power. Because the signal amplitude is very large, the power amplifier circuit mainly amplifies the current signal.
According to the working state of the transistor, the low frequency power amplifier can be divided into categories A, B and AB.
A class is like the transistor common-emitter amplifier circuit, the transistor works completely in the entire signal cycle, the advantage is that the linearity is good, the disadvantage is that the output power is small and the efficiency is low.
Both category B and category AB are use two transistors to amplify the signal cycle, and the two transistors work in turn, the advantage is that the efficiency is relatively high, the output power is relatively large, of which AB are the most widely used.
OCL Power Amplifier
OCL ( Output Capacitor Less ) Power Amplifier is a category B Power Amplifier without Output Capacitance.
The core components in the diagram are two transistors, and the NPN transistor is responsible for amplifying the input signal ; for the first half of the week, the PNP type transistor is responsible for amplifying the input signal;
The output of the two transistors can be combined to get the complete signal waveform on the load R. In order to amplify the negative half cycle of the AC signal, the OCL power amplifier circuit needs to be powered by a dual power supply. Both of the transistors form a common collector amplifier circuit, which has the function of current amplification, but does not have the function of voltage amplification.
This article is from Allicdata Electronics Limited.