Using TINA simulation, why is there such a big difference between the amplifier output current and the power supply current?

zpccx

Using TINA simulation, why is there such a big difference between the amplifier output current and the power supply current? [Copy link]

The circuit diagram is as shown in the figure. The power amplifier is OPA544, the power supply is ±12V, the input of the same direction input is 4V, the gain G=+1.5, the output voltage is 6V, the load R=3Ω, so the output current = 2A, the power on the load is about 12W, but the simulation shows that there is only about 4.2mA current on the positive and negative power lines. Why is the current so small? From the perspective of energy conservation, the main power is input by the ±12V power supply, and this power is also unbalanced?

chunyang

The simulation is just not real.

chunyang

For beginners, simulation can at best help them deepen their understanding of circuit principles, but it cannot replace hands-on practice. You cannot become a qualified engineer just by relying on simulation.

xiaxingxing

4.2mA is the current that the op amp "absorbs" from the power supply. It corresponds to the quiescent current in the datasheet (usually given in the datasheet). 2A is the load current, and this value is related to the load. The 4.2mA and 2A in the question have nothing to do with each other. 4.2mA*12v+2A*12V=total power supplied by the power supply.

zpccx

xiaxingxing posted on 2017-12-21 20:17 4.2mA is the current that the op amp "absorbs" from the power supply. It corresponds to the quiescent current (Quiescent Current) in the datasheet. Generally, the datasheet will give...

I don't quite understand. When I design the power supply, I need to consider the power of the chip itself and the maximum power of the load. The power of the op amp comes from the power supply, which is roughly equal to the output current Io x output stage Vce. The current comes from the prevented power supply. The op amp only has this pair of power pins. According to your meaning, when laying out the board, there is no need to draw the op amp power pin trace very wide?