Convert single power supply to dual power supply

TDA2030 is a high efficiency operational amplifier. Using its complementary output stage, the unipolar power supply can be split into two and converted into the bipolar power supply required by some low-power circuits. The circuit is as shown in the figure above. R1 and R2 with equal resistance form a voltage divider to make the voltages of the upper and lower parts equal. The midpoint of the voltage divider is connected to the non-inverting input terminal of the operational amplifier, and the operational amplifier is connected as a voltage follower to make the potential of the O' terminal and the O terminal equal. The O' terminal is a virtual point, and it must be isolated from the ground of the input power supply. If the bipolar power supply is taken out directly from R1 and R2, the internal resistance of the power supply will be large, the load capacity will be poor, and the practical value will be little. After using the operational amplifier, the two sets of output power supplies have very low internal resistance and the load capacity is enhanced.