CX7131 is a high-precision off-line switching power supply circuit, which is used in low-power AC/DC chargers and adapters. CX7131 uses primary side Sampling is used for precise constant current and constant voltage control, which can save the optocoupler and TL431 in general applications.
In constant current mode, the output power can be set by the external sampling resistor Rs connected to the CS pin. In the constant voltage mode, the various working modes of the chip can be
To ensure a higher overall conversion efficiency. In addition, the chip has built-in cable voltage drop compensation, thus achieving good load regulation. CX7131 in constant current
It works in PFM state in constant voltage mode, works in PWM state in constant voltage mode, and works under frequency reduction at light load.
CX7131 provides power-on soft-start function and various self-recovery protection functions, including cycle-by-cycle current limiting protection (OCP), VDD over-voltage protection protection (OVP), VDD over-voltage clamp, under-voltage lockout (UVLO), over-temperature protection, etc. The frequency shaking function of CX7131 can provide better EMI performance .