This solution uses the high-performance current-mode PWM controller EG1253 as the main control chip, which greatly improves cost-effectiveness compared to the traditional UC3842 solution, mainly focusing on the following advantages: significantly reduced number of external components; external NTC temperature protection function; optocoupler open-circuit protection; light-load frequency reduction and burst mode; built-in slope compensation; low quiescent current, etc. The three-stage charging management chip uses EG4321, which integrates constant voltage, constant current, and lamp control modules, as well as dual-LED charge indicators and fan drive circuits.

The control part of this scheme adopts the dual tube forward and backward dedicated chip EG12523, which has VCC undervoltage protection (UVLO), VCC overvoltage protection (VOP) Periodic current limitation, overload protection, soft start, etc. The main circuit of this scheme adopts a dual tube flyback converter, which has the following main advantages compared to single ended flyback: 1. It reduces energy loss, eliminates buffer loss and heat generation issues, and the leakage inductance energy when the switch tube is turned off is fed back to the DC input power supply through the freewheeling diode; 2. The voltage stress borne by the switch tube is only the DC input voltage, which is more suitable for high voltage and wide input scenarios. When the switch tube of a single ended flyback converter is turned off, the voltage it bears is equal to the sum of the maximum DC input voltage, the secondary side refracted voltage, and the leakage inductance peak voltage, requiring higher voltage resistant devices; 3. Compared to other multi tube converter topologies, there is no risk of direct short circuit between the two switching tubes in the dual tube flyback converter. Due to the two switching tubes being on the diagonal of the bridge, during normal operation, both tubes conduct and turn off simultaneously. At this time, the primary winding of the transformer is subjected to voltage, so there is no risk of direct current.

The front-end control of this scheme adopts an integrated 600V half bridge drive current mode PWM controller EG12523, with VCC undervoltage protection (UVLO) Periodic current limitation, overload protection, soft start, etc. The secondary adopts FAN6204 synchronous controller, with significantly lower conduction loss than the Schottky diode scheme.

The control part of this scheme adopts the dual tube forward and backward dedicated chip EG12523, which has VCC undervoltage protection (UVLO), VCC overvoltage protection (VOP) Periodic current limitation, overload protection, soft start, etc. The main circuit of this scheme adopts a dual tube flyback converter, which has the following main advantages compared to single ended flyback: 1. It reduces energy loss, eliminates buffer loss and heat generation issues, and the leakage inductance energy when the switch tube is turned off is fed back to the DC input power supply through the freewheeling diode; 2. The voltage stress borne by the switch tube is only the DC input voltage, which is more suitable for high voltage and wide input scenarios. When the switch tube of a single ended flyback converter is turned off, the voltage it bears is equal to the sum of the maximum DC input voltage, the secondary side refracted voltage, and the leakage inductance peak voltage, requiring higher voltage resistant devices; 3. Compared to other multi tube converter topologies, there is no risk of direct short circuit between the two switching tubes in the dual tube flyback converter. Due to the two switching tubes being on the diagonal of the bridge, during normal operation, both tubes conduct and turn off simultaneously. At this time, the primary winding of the transformer is subjected to voltage, so there is no risk of direct current.

A 5V40A AC-DC dual-tube forward synchronous rectifier power supply solution based on the EG1166 chip, using a dual-tube forward excitation synchronous rectifier topology, achieving a wide input voltage range, stable high current output, and efficient energy conversion. Its input voltage range is AC 176 - 265Vrms, adaptable to various AC power supply environments; the output current reaches 40A, with an output voltage of DC 5V, capable of providing stable and sufficient power for devices with higher power demands. The maximum efficiency of this solution can reach over 89%, maintaining high efficiency even under full load, effectively reducing energy loss.