This efficient DC 12V 5A power supply employs an isolated-flyback power-supply controller that provides Constant-Voltage (CV) using an optical coupler to improve transient response to large-load steps. The power supply 12V 5A processes information from opto-coupled feedback and an auxiliary flyback winding for high-performance control of output voltage and current. The output voltage is regulated accurately by a high-performance voltage-mode amplifier with an accurate voltage reference. The 12V DC 5A power supply comes with excellent efficiency performance. Its power-saving technologies limit the no-load power consumption to lowest level. The precise output over-voltage protection greatly enhances the system reliability of the 12V 5A smps power supply. Effective thermal management reduces thermal stress on power supply reliability, allows the 12V DC adapter power supply to operate at full power in higher ambient temperatures (see our UL/TUV documents).