This is a one simple design for buck booster inverting. This circuit is negative booster inverting. This circuit is based on LM2574. This is the figure of the circuit.
LM2574-12 in a buck-boost configuration to generate a negative 12V output from a positive input voltage. This circuit bootstraps the regulator’s ground pin to the negative output voltage, then by grounding the feedback pin, the regulator senses the inverted output voltage and regulates it to −12V. For an input voltage of 8V or more, the maximum available output current in this configuration is approximately 100 mA. At lighter loads, the minimum input voltage required drops to approximately 4.7V.
