Review on 💡 Packed Power: PEMENOL 5PCS AMS1117-3.3V Buck Converter – Efficient 3.3V Step-Down Voltage Regulator for Stable Power Supply (800mA) by Erick Bowers

I bought these DC/DC converters because I've been experimenting a lot with electronics and needed a small regulator module to drop my 5VDC power supply down to 3.3VDC to meet an ever increasing power a number of electronic devices. Microcircuits that operate on 3.3V DC. I was very impressed with these little devices. Received them on time, dispatched by Revain in a suitable anti-static metal bag inside a padded envelope. They arrived in perfect condition, all five units connected together in one strip. .Because I was so excited to try them, I already had three of them disconnected, so I couldn't get the picture until after two of them were still connected. To separate them, they simply had to be separated along the V-shaped cuts between the modules. Very easy. The units are tiny as you can see in the photo I took next to the US penny. Thanks to the rectangular connector, they can be mounted vertically on a standard breadboard and take up very little space on the board. Judging by the schematic, they use an Advanced Monolithic Systems AMS1117-3.3 voltage regulator chip with a low voltage drop in SOT-223. Package. AMS1117 is a good linear regulator chip that can work with a maximum input voltage of up to 15VDC and a maximum output current of 1A, and has overcurrent and overtemperature protection. The design of the controller corresponds exactly to the data sheet; Offering a 22uF tantalum capacitor at the output, this block continues with 22uF ceramic capacitors at the input and output of the regulator and adds 0.1uF capacitors to the input and output pins. This is a very nice touch added by an experienced designer who knew what he was doing. It is also nice that the LED is *not* overdriven, as is often the case with hobby modules like this one. I don't know why designers do this, they seem to think that the brighter they make the LED the better. But that's bad for the lifespan of the LEDs, and sometimes I find that an LED that's too bright is almost blinding. The LED has a 1kΩ series resistor that limits the current through the LED to a reasonable 1mA. It's bright enough to be seen, but not so bright that it's blinding. Judging by the build quality of the blocks, all of the solder joints have a good shiny appearance and a large amount of solder. The AMS1117 chip in my modules was slightly offset, but that's purely cosmetic - the pins connect well to the board, and that's important. The device is nicely labeled with clear pin function markings. I tested several devices with my electronic load to see how they behave under load. The devices I tested had an output voltage of 3300 VDC (I have a calibrated meter), which is to be expected since the AMS1117 is set to have an output voltage accuracy of 1.5%. I then applied various loads from 100mA up to the full 0.8 amp rating. The output was as expected, very close to the 3.3VDC output. As expected, the blocks heat up under high loads. These blocks are linear regulators, meaning they convert extra voltage into heat. Although it sounds wasteful, linear regulators are great because they have a very clean output without the switching noise found in switching converters. This might be important - I was recently working with an ESP32 CAM board and there were a lot of noise bands in the picture. The transition from a switching power supply to a linear one greatly improved the picture. Because they convert surge to heat, thermal design is important. With my test setup I was able to confirm that the vendor advertised output current limit of 800mA at 5VDC input is accurate. With an input voltage of 5 VDC, these devices deliver 3.3 VDC at 800 mA while remaining within the thermal limits of the chip. Once again, the designer knew what he or she was doing. At higher input voltages you need to decrease this maximum limit as the output current increases. However, since the chip has overheat protection, overheating of the chip will cause its performance to decrease. So if you run them with a high input voltage and draw a lot of current, you may see an output voltage of less than 3.3VDC at high currents because the device is overheating. The temperature characteristics of the chip work as specified in the data sheet. In summary, I am very impressed with these linear controller blocks. They are well designed, work well and are excellent value for money. If I need more than the five units purchased I will have no hesitation in purchasing more from this seller.