The rest of the electronics include one 78L05 fixed voltage regulator, one TL431 precision shunt regulator, and a LM358 operational amplifier. An exception is that the recommended 1uF bypass capacitor (C1) is not used in this module, provision is already provided in the PCB, though. The core of the design merely follows the typical application example (see below). Below you can see the function block diagram of XL4015 (XL4015E1). An over current protection function is built inside so that when a short circuit occurs, the operation frequency will be reduced to 48KHz. According to its datasheet (Rev 1.5) the PWM control circuit can adjust the duty ratio linearly from 0 to 100%. Needless to say, at the heart of the module is a XL4015 chip from XLSEMI ( which is a 180 KHz fixed frequency PWM step-down (buck) DC/DC converter, capable of driving a 5A load with high efficiency, low ripple and excellent line and load regulation. I included this session to share information about the background electronics I think might be useful to people. What follows is the thorough inspection of the module. It’s advised to adjust the voltage level at first, and then the current level (this fine-tuning procedure will be discussed in detail later). Likewise, clockwise turning of the current adjustment (I-ADJ) trimpot increases the current limit while counterclockwise action decreases the current limit. Slowly turning the voltage adjustment (V-ADJ) trimpot clockwise will raise the output voltage gradually, and a counterclockwise rotation will lower it. However, when used as a general-purpose power supply, the battery charging indicator LED will work as a ‘load-on’ annunciator.
ADJUSTABLE DC TO DC CONVERTER FULL
Further, there are three LED indicators – the first one near the input connector is the constant-current (cc) indicator, while next two LEDs are intended mainly for battery charging applications (battery charging and battery full indicators). This is the photograph of my XL4015 Step-Down DC Module with CV/CC Control.Īs you can see, apart from the input and output screw terminal connectors, there are two multiturn trimpots to adjust the output voltage and output current. This is the quick specification chart of the module posted by the seller. This time the module has onboard constant voltage (CV) and constant current (CC) control feature which is useful for general purpose power supply and battery charger applications. I tried it immediately in a new experiment. I purchased it from an online seller in China. I recently received an improved version of the same module. In an earlier blog post I did a teardown analysis of the XL4015 DC-DC Buck Converter module.