Analysis of efficiency calculation method of three driving h bridges

It is common to drive DC motor with a H-bridge to use, and there are three common ways, triode drives, MOS tube drives, integrated circuit drivers. So, for these three ways, we probably know that there is a respective advantages and disadvantages. The integrated circuit is relatively convenient, but the efficiency is relatively low; MOS tube efficiency is the highest, and the triode efficiency is in the middle, our mind has such a probably impression. However, what should be calculated in the specific circuit and how work efficiency should be calculated here, I will discuss the efficiency calculation method of three driving h bridges and everyone: The reason why the work efficiency is high, and the root is due to the pressure drop in the collector and the emitter on the transistor and the emitter on the transistor. Although we usually analyze it, it can be ignored, because only zero a few volts, But when calculating efficiency, it is necessary to consider it. In order to facilitate comparison, the drive current of the H-bridge is positioned at 2A level, and the voltage is between 5 - 12V. Take a DC motor that drives a 5V, 2A as an example. Triode drive, Key components: S8050 S8550 The reason why the power consumption is mainly due to the triode conduction, and there is a pressure drop, from the above diagram specification, the S8050 pressure drop is 0.5V, and the S8550 pressure drop is 1.2V. The triode consumption is: (0.6 + 1.2) * 2 = 3.6W motor is: 5 * 2 = 10W Efficiency is: 10 / 13.6 = 73.5% Personally, the above circuit should be better to change the NPN and PNP. I have no verification, this circuit does not have product performance analysis, only explore the efficiency. MOS Tube: IRF9540 IRF3205 The MOS-conduction pressure drop is calculated by turning on the resistance. The IRF9540 on-resistance is 0.2Ω, the conduction drop is 2 * 0.2 = 0.4V; IRF3205 is 0.008Ω, the conduction pressure drop is 2 * 0.008 = 0.016V MOS consumption is: 2 * (0.4 + 0.016) = 0.832W The power obtained by the motor is: 5 * 2 = 10W Efficiency is: 10 / 10.832 = 92.3% Integrated circuit: L298N Vcesat (h) is 2.7V of the upper bridge arm, 2A is 2.7V Vcesat (L) is a pressure drop of the upper bridge, 2.3V at 2A Vcesat is the pressure drop of the upper and lower bridge, 4.9V 2A Integrated circuit L298N consumption is: 2 * 4.9 = 9.8W The power obtained by the motor is: 5 * 2 = 10W Efficiency is: 10 / 19.8 = 50.5% Through the above analysis, it is possible to see that the efficiency of the MOS tube is higher than that of the triode is higher than the integrated circuit, and the H bridge cost is low, the efficiency is high, but it requires a relatively high technical requirements, and the stability is to be verified And the integrated circuit is convenient, but the efficiency is relatively low. It is the same as different transistor analysis methods, and it is better in accordance with the above parameters. You can also try your own H-bridge efficiency, an accessory is a specification of the triode, MOS and L298N. Edit: hfy, read full text