XL4005 aluminum substrate

The XL4005 specification says that it can reach 5A current. I am not sure whether it refers to the maximum current on the switching circuit or the stable output current. In short, try to select the parameters according to the maximum output of 5A. Soldering with a soldering iron can be painful because the aluminum substrate conducts heat too quickly. Anyway, it was very uncomfortable to solder a small capacitor on my T12, and the temperature had to be adjusted to over 400. It is more recommended to use heated table welding. ## The input/output GND and the aluminum plate are connected, so there should be nothing wrong with it. The positive terminal can only be soldered, because the terminals are all through-hole soldered, so they cannot be used. ## The input and output in the capacitor document use a single 470uF electrolytic capacitor, but I only have 220uF on hand, so I connected two in parallel. ## The output current of the freewheeling diode and inductor is 5A, with a margin of 30%. The rated current of the diode and inductor should be greater than 6.5A. It should be okay to use the SS54 with a maximum of 5A, and the SK1045 is 10A 45V. The inductor is 1265 specifications, 33uH, saturation current 8A, temperature rise rated current 6A. ## The potentiometer voltage can be adjusted with resistors R1 and R2, or R1 can be removed and replaced with a potentiometer to adjust the output voltage. The trouble is that commonly used 3296 potentiometers are all soldered through holes, and only patches can be used on aluminum substrates. So I designed a 3296 vertical potentiometer patch pad, as shown in the actual picture: ! [Picture.png] Without resistor R1, cut the potentiometer's pins short, bend them, and stick them on the pad. ## Capacitor C7 is not installed in the actual picture because C7 is a compensation capacitor. According to the specification, it is used to improve stability when the voltage is high, so it can be installed or not.