XL4015 Power Module as the name suggests is a PWM fixed frequency DC to DC Buck power module. XL4015 Step-Down Buck Power module operates on 180 kHz but still provide smaller sized filter components and is capable to drive a load of 5A with load regulation, high efficiency and low ripple. XL4015 DC-DC Step Down Module comes with onboard CC(Constant Current) and CV(Constant Voltage) control feature which is very handy in applications like battery charger or power supply. This Constant Current and Constant Voltage feature is implemented by adding 78L05 fixed voltage regulator, TL431 precision shunt regulator and an LM358 operational amplifier to the circuit.