 Hi, I'm N.P.I. Hi, I'm N.P.I. brought to you by Digikey this week, so it's NXP. What is the new product of the week? Okay, yes, from NXP. This is their first load switch. I was like, oh, maybe they have stock other ones, and this is just their latest. Nope, this is their first time getting into this market. This is the NPS 4053. I was anxiously waiting until this was in stock. And it's now in stock at Digikey, so I feel like it's time to highlight it. So this is a 5.5-volt or 5-volt load switch, 55 mOhm. It's, you know, are on resistance up to 80 mOhms at VIN 2.5. And basically, it's what it sounds like. You have an input voltage and output voltage, and you want to connect the input to the output, you know, so that you can power a sub-circuit, turn it on, turn it off, have current limiting, have undervoltage lockout protection, have short circuit protection. It can be used for a couple of different reasons. One can be used to turn on and off a circuit to reduce power or to protect against, again, like short circuits like you have. In this case, the example for the application is USB or USB device malfunctions. You don't want to take down the hub and the computer, so you would be able to disconnect it cleanly. And this is just a very nice all-in-one integrates switch that does a lot of things. So, a lot of times when we say, you know, you want to turn something on or off, you might use a mechanical switch, and, you know, we've done that before. We have circuits, and I'll show it in a little bit on, like, a metro, we use a mechanical switch to, sorry, on the BFF lipo for QDPI. We actually just use a mechanical switch to turn things on and off. The switch is rated for the amount of current we need to pass, so you just, you know, toggle it left or right, and on or off, or here's an on-off mechanical switch that's designed to carry, you know, up to 5, 10 amps of current. But, you know, that's mechanical. So, for electrical, you know, you can use a relay or we covered SSRs a bunch of times on INMPI. You can check out those videos on when you can use an SSR. These are also great, very high currents, very fast, you know, have not mechanical disconnection, but good electrical disconnection between input and output. But these are really big. They're meant for, like, extremely high currents and extremely high voltages, you know, 200, 300 up. So, this is, you know, an example of a mechanical switch that we've used. It's really simple. You want to either connect the VBAT voltage, the battery input to the 5-volt power line or not. You have a mechanical switch, you flick it to connect, you flick it to disconnect. In this case, it's a DP-DT, and I kicked it in parallel to get twice as much current rating. I want to make sure that the 5-volt doesn't feed back into the battery, and so you'll see that diode. And, like I said, this is a mechanical solution. It works fine, but it tends to be for either, you know, either you have a small switch in its low voltages and current, or it's a very big, very expensive relay or SSR or switch. If you want to do it electrically, so you have a voltage controlling whether something is connected or disconnected, another common setup is the PFET. So, T2, the transistor in the middle there is a high current P type MOSFET, and I think it can pass like 4 amps or so, and I think it's good up to 12 volts VDS and VGS. I do have a switch there, but you can wear that. That switch is just, you know, if you want to also connect it electrically. And PFETs do quite well, except there's a couple of downsides. This is a high side PFET. So one is if you want to control this from a lower voltage, you'll have to have another N channel or NPN type transistor because you see the gate is pulled up high to the input voltage, and so you don't want that to go into your microcontroller. So you'd have to have a separate transistor just to switch on and off the gate. The second thing is that you see in the symbol for the PFET transistor, T2, there's that little diode that's pointing back. That's the body diode. And in this case, what would happen is that if you, you know, had a separate power supply or maybe some leakage into the VIN voltage, it could go back into the power supply, which is not good. You don't want to have bidirectional switch current. You want to have no direction at all, like neither from input to output or from output to input. Sometimes you can, from this case, I put in another diode. You see D1 and that makes sure that there's absolutely no way for any backfeeding or sometimes people use back to back transistors, but now I have two transistors and you have to switch both of them and it gets a little more complicated. And, you know, you need a couple of passive resistors as well to do the pull ups and downs. So this is a common, you know, way to do load switching, but there's a lot of downsides. There is not true disconnection. And another thing is, you know, I've used this in, a feather design once to switch on and off an I2C power supply to, you know, turn on I2C sensors and it worked fine when the I2C sensors were 5, 10 milliamps, but when it hit 50 milliamps, because turning on the MOSFET is like instantaneous, there was a huge current spike as it powered, you know, some capacitors or some high-powered electronics on the output side and it would brown out the input because of this like kind of instant fast rush of current. And so there's no current limiting here. You could add a crowbar circuit, but now, now it's getting really complicated. It's getting to like 10 components just to turn on and off some circuitry. You know, another solution that you could do is have a separate regulator in this case. You know, this is another design type I use. So instead of a PFET, I use a separate regulator and then the enable pin is tied to an IO and then you can turn on and off. This works great as long as you have a higher voltage with enough dropout that, you know, when you have that current rush, it doesn't affect the other power supplies. But, you know, you don't always want to have a regulator for each one. You know, you have to add more capacitance. You have to pick one that doesn't have, you know, feedback voltage from output to input. Sometimes you don't have headroom anyways for an LDO. You know, you maybe have a DC-DC power supply that is providing a lot of current to multiple subsystems. And also the regulator could be kind of big because it's also doing regulation when you really just want to enable or disable it. So thus, the NXP NPS 4052. So here it is. It's a two millimeter by two millimeter package. So it's nice and small. It's very simple. You have the input and the output. You have the logic switch on. You have a flag output. So that is something that tells you when then there's an error. If there's a short circuit or undervoltage or overvoltage or whatever. I limit, which is kind of neat. The resistor can be used to limit the current to convert from constant voltage to constant current. And there's a duplicate output because, you know, you want to have a, sorry, there's the output voltage. And then there's a ground and thermal pad. So very simple. Only six pins required. All of them do something. So this is like bare bones. I will say that, you know, the one thing to watch for, this is designed for three to five volt logic input. You know, it's, you saw the example was to use it for USB, but it does do up to two amps output current, just quite a bit. So this is good for high power switching on and off. You can set the limit to anywhere between zero to two volts, sorry, zero to two amps, but yeah, you can't really go above 5.5. And honestly, I would stick to between three and five volts for this. One of the nice things is you can see, you know, you turn it on, it has this kind of the slow start is what they call it, where you have a slow ramp up, which is often better for electronics. They kind of want the power to slowly ramp. They don't want it to like go up, ring, you know, go up and down. And then also in turning off, it's instantaneous. So you want like slow start on and quick start off or quick off. It handles transgences pretty nicely. You'll want, of course, capacitance on there. It reacts to short circuits very quickly. You can see the bottom right when there's a hard short, it like pretty, you know, there's a quick current spike and then immediately, you know, the protection kicks in and it turns off the output within, you know, a few microseconds. Here's just a short circuit protection that they talk about. What is nice is that when the short circuit goes away, it does recover. So like, you know, the current limits, but it will, you know, when the short circuit is released, it's like, okay, you know, I'm good to go and it comes back on. Some voltage regulators and switches latch on or off. And then finally, there's the fault output flag kind of handy. So it tells you over temperature, I think under voltage, over current, et cetera. And then of course the enable pin can be controlled. If you have a five volt power supply, you can control it with a lower voltage. I think the neat thing here is the constant current can fill the, it's really nice. You just pick a resistor and then you can limit the current and it will automatically convert from constant voltage to constant current mode, just quite nice because it means, you know, if you have something that's taking a little bit too much current and like a fuse, which will just instantly cut it off, you'll just, you know, slowly reduce the power and maybe you have a chance to recover. And they're in stock and you can see 3000, like a full reel. They just came into stock today. So you can pick these up. That's a very nice first load switch available from NXP. And we have a video. We're going to play it. Now let's take a look at some of the key product features that the MPS4053 has to offer. The input operating voltage range for the MPS4053 is 2.5 to 5.5 volts. At 5.5 volts input, the RDS on is 55 mili ohms. This allows for lower power dissipation, lower voltage drop across the pass-fet in greater thermal performance. The maximum continuous current that the device can withstand is 2 amps. This is the amount of current the device can sustain indefinitely, whereas peak and rush current is only sustained for a short amount of time. The MPS4053 also features a precision adjustable current limit that can be programmed with an external resistor from 110 milliamps to 2.5 amps. This device also features an active low fault pin, which asserts low under an over-temperature, over-current, or reverse voltage condition. One of the unique features about this device is its I limit pin protection. This means the device will continue to operate normally if the I limit pin is shorted to ground or open and will continue to regulate current normally. This device also features active reverse voltage protection, which means the pass-fet will turn off if the output voltage exceeds the input voltage by about 75 millivolts typical. Lastly, this device features built-in soft start, which allows the output voltage to be applied smoothly and gradually to the downstream load to prevent the instantaneous delivery of power which can damage the load. Next up, let's take a look at the MPS4053 versus the competition. The MPS4053 offers best-in-class on-resistance, maximum continuous current, I limit pin open and short protection, reverse voltage triggering threshold, current limit accuracy, and all of these devices offer over-current protection over-temperature protection. Looks like an MPI. Hi, I'm MPI.