BOJACK IRLB8721 MOSFET Transistors IRLB8721PBF 30 V 62 A N-Channel Power MOSFET TO-220 (Pack of 10 Pcs)

Product Information

Power MOSFETs are most often used a switches where they are turned fully ON or OFF to control a load such as a motor or high power LEDs. They are ideally suited for this because when the MOSFET is turned fully ON (Saturation Region), it has a very low resistance and can pass a lot of current without much power being dissipated in the device similar to a mechanical switch. When they are turned OFF (Cut-Off Region), they act as an open circuit much like a mechanical switch would when it is off. I have noticed that when using the IRLB8721, my LEDs are always on, and I am not able to switch them off. I did make sure not to mix up the Drain and Source, yet still not working. R DS(on) : Static Drain-to-Source On-Resistance is the minimum resistance of the MOSFET when it is driven to the fully ON state known as the Saturation Region. The key to look for here is that R DS(on) may be specified at one or a couple of V GS voltages. I D : Continuous Drain Current is the maximum current that the device can handle. this will often be specified under several conditions such as at 25C room temperature and at 100C or similar high operating temperature. Achieving the maximum current through the device assumes that you are driving it fully on and that appropriate heat sinking is applied. If you have a device that draws 10A, you need an I D> 10A. Generally the higher the I D rating of the device compared to the amount of current you need to pass though it, the easier it will be to manage thermals. When it comes to LED strips, the main difference is between analog and digital LED strips. Analog and digital LED strips work differently and produce different results. So, whether you need an analog or a digital LED strip will depend on the project you want to build.

The other parameter you need to consider is the total gate capacitance as that affects how fast PWM can be used (depending on the gate drive current).A well-designed switching regulator probably won't need a heatsink. A linear regulator will probably overheat even with a heatsink.

There are cutting marks along the strip marked with a scissors icon that shows you where you can cut your strip as shown in the figure below. This strip has segments of three LEDs. I used a logic level converter to convert my 3.3V signal to 5V, which works perfectly so far. Now I just need to look in to whether PWM is still possible with this setup.Most regulator chips are thermally protected and they'll shut-down safely without burning-up. Then, they'll work again after they cool down. (Transistors & MOSFETs will just permanently die.)

One meter of your analog LED strip can draw approximately 1A per LED pin when all red green and blue LEDs are at full brightness (which produces white). I'm quite new to working with arduino and I'm *really* fresh to using the ESP32 and have just discovered that I'm not able to use my current mosfets (IRF520/540) from the 3.3V pin (now obvious to me, as they activate at 4V and 10V (I think) respectively). If using this device with a 5V uC, it is possible to drive the MOSFET gate directly from an digital output pin. When driving it this way, the MOSFET is not being driven to be quite fully ON and so the maximum resistance through the device increases from about 8mΩ to about 16mΩ. While still very small, it does mean that the device will drop double the amount of voltage through it and dissipate twice as much heat, so it’s maximum current handling capability will be cut to about half of the stated amount which is usually fine for most applications. N-Channel MOSFET Theory of Operation If there are two voltages listed, the highest voltage will be the voltage at which the device is fully saturated and show the lowest resistance, often 10V. The lower voltage is often around 4.5V and shows the resistance if you were to drive it directly off of 5V logic. Having this specified implies that the device is at least partially 5V logic compatible even if it isn’t being driven to full saturation.

Analog LED strips have their LEDs wired in parallel. The whole strip works as a giant RGB LED. So, you can light up your whole strip in many different colors, but you can’t control LEDs individually. This means your strip can only be one color at a time. This type of LED strips are cheaper than the digital ones and easier to use. By calculating the RC time constant and thus the rise/fall time of gate voltage - during rise and fall the Looking at the example spec sheet below, this is telling us that to drive the MOSFET to full saturation requires a V GS voltage of 10V where max resistance is 8.7mOhm. If we were to drive it instead at 4.5V directly off of 5V logic, the resistance basically is twice as high, but is still only about 16mOhm. I am a beginner when it comes to electronics so I would appreciate your help with a simple project I am working on and have been struggling with for several days.