 It's time. Digi-Key and Adafruit present. Okay. This week's IonMPI new product, Lady Adidas from Texas Instruments. That's right. What is it? I love Texas. They've got great chips, and they've got great barbecue. This week's IonMPI is the TI BQ-25792. I haven't written down, so don't forget it. The BQ-25792, which actually wasn't on the Digi-Key new product section, but it's such an awesome chip. I saw it, I think, through the TI RSS feed, and I was like, okay, I got to cover this because this is such a great charger chip. This is the eval board. You can pick up the eval board from Digi-Key 2. They also have chips in stock. I'm also trying to pick IonMPI chips that you can actually buy at the time of viewing because I know there's a global chip shortage, but they do have them in stock. That's why it's this week's IonMPI. The BQ-25792. Here you go. This is a chip. This is a simplified schematic because there's a bunch of control pins that aren't shown here. Basically, it's a buck-boost battery charger. You can charge one to four series batteries for S, so that's four batteries in a row, just like, I think, 18 volts or something. It's a buck-boost converter charger, which means that you can charge it from almost any voltage. Then it even has an on-the-go mode where it can buck-boost out as well. It's kind of like an all-in-one power charger manager updater. It's got great standalone and I2C support. It kind of does everything. I've looked at a lot of chargers and there's always like, here's a simple one that just does 1S batteries and only charges at a certain rate, but this one was really quite a delicious chip. It can support USB PD. Note that it doesn't do the USB PD negotiation. You would have that done by a separate chip if necessary, but it does support very high voltage input from 3.6 to 24 volts in. You can choose 750 kHz or 1.5 MHz switching frequencies for the buck and boost. You can configure the charging current over I2C or with a resistor, so you can have a rough charge current with a resistor and then, as rough as your 1% resistor is, or you can program it in over I2C. There's max power point tracking support because it's a buck-boost, so it has input voltage and input current limiting, but there might be something that sometimes the voltage going higher or the current going higher may change the efficiency overall. It tries to find the highest efficiency and it does have D plus and D minus lines to detect USB chargers. Like I have the Apple resistor charger divider thing where the voltage on the D plus and D minus pins when not connected to a host or peripheral chip can tell you basically what the charger is capable of. I recently started using BQ charger chips, so this is our solar LiPo charger, USB, DC or solar using a BQ chip, not this one, but this one's, I think, a linear charger, and it works great. I really love these BQ chips. TI is in making LiPo and other battery chargers for a very, very long time. I noticed recently they really stepped up their power supply and battery game. Every time I look at a chip I'm like, they really thought of everything. The first thing is it has the standalone mode where there's an iLimit pin and a PROG pin. You can see here by picking a certain kind of resistor you hard-code in the number of cells. It's 4.2 volts per cell, so it's like one cell is 4.2, two cells is 4.8 and then up to 16.6. I tend to use 3.7 volt, 4.2 volt, single cell configurations the most, but I've noticed a lot of people who do robotics or drones, they tend to use 2S or 3S cells, so this is really perfect for them. One of the nice things is that it supports USB or DC inputs and the thing that's really frustrating about DC linear chargers or even buck or boost chargers is you don't know when you plug in a DC 2.1 millimeter outlet, something into your outlet, the wall wart. You don't know what you're going to get. There's wall DC adapters that give you 3 volts up to 24 volts. You have no idea and that's what I really like, that it's so zen. No matter what you give it, it gives you the right voltage out to set the output you want. It has, like I said, a buck-boost converter. This is, for example, the graph of using a 1S battery, so about a 4-volt battery, and it shows you here the V-buses from 5 volts at the top all the way down to 20 volts. Yes, the efficiency goes down, but that's okay, which makes sense. It's less efficient. You're going to lose some efficiency with the buck-boost, but you can still charge from a 20-volt power supply. It's really fine. Likewise, here's a 3S battery charger, and you can see the yellow line at the bottom is 5 volts. It's where it's trying to boost up to about 12 volts, so it's not as efficient. And then 9 to 12, that's closer to the actual battery output voltage. You're going to get more efficient. And then 3S is kind of nice because 15 or 20 volts is a little bit above, but you're not over-driving the buck-boost converter. Basically, what I like about this is it shows your input, your output, it doesn't matter. It's all possible. It'll just do the right thing. It has dynamic power management, which is what I use in the solar charger that I showed you earlier. So if you have a wall adapter and it can supply 1 amp max, but you're trying to charge a battery and it likes to be charged at 2 amps max, you don't want to draw 2 amps from the wall adapter because it'll collapse the voltage. The wall adapter will overcurrent and shut down. So you have to be very careful. As you see that voltage drooping, you want to stop before you overload the adapter, overload the USB port. The cable can have a voltage drop as well. So it uses this dynamic power management, which checks the input voltage and slowly turns down the current as the voltage starts drooping. There's also this input current optimizer, which I think you could turn on over I squared C, and this actually does more of a max power point tracking thing because, again, sometimes the voltage going up or down, just because it's going down doesn't mean it's going to be less efficient and going up as it needs more. It can be either way depending on, like you saw those curves, it kind of depends on your input voltage point and your output battery voltage. So this is kind of neat. I want to try this because I wonder how it would work with solar because, again, solar is so specific in particular about getting that max power point. But this does seem to kind of like noodle around the voltage and current to try to find that max power point. So this will get you better, faster charging because you're going to get the max amount of power out of your power supply. It also does, like I said, it can do USB D plus D minus detection. Depending on the voltage dividers on those two pins, it can give you a hint about what the power supply can give you. And so this, if you connect the D plus and D minus pins, it'll do an analog digital conversion on those and kind of try to figure out, like, what does the power supply think it can provide? Even if it can take more power out, I'm going to limit it to what it's telling me is the max. It's a polite way of working with USB wall adapters. And then, of course, there's this I squared C interface. And so you can use that to read the analog digital converter inside. So, like, everything from, like, the temperature to the battery input voltage to the power input voltage to the current for charging and the current for the buckwheat converter is all measured. And so you can read that whenever you want to see what the status is and, like, do an analysis of how your battery life is going on. So that's the I squared C port, which, again, is optional. You don't need to use it. It runs perfectly fine in standalone mode. And finally, I thought this was kind of nifty, although I'll be honest, I've never used this myself. And the thing is that you can put it into on the go mode. Instead of using the buckboost to charge the battery, the battery then, like, goes backwards and is buck-boosted to an output voltage that you set over I squared C. So if you want it to be, like, a 5-volt output or a 12-volt output boost converter or buck converter, especially if you're, like, kind of in the middle of, like, between what the battery nominal voltage and peak-put voltage is, this could be kind of neat. You don't have to use it. Of course, you can just take the system voltage out and it'll give you the battery voltage. Of course, it does power-sharing. So if it's powered over DC, you'll get... it won't drain the battery. It'll just get power from DC. And then when the DC is connected, it charges from the battery instead. And this is just some efficiency showing that you can, you know, get about, like, half an amp to an amp from the on-the-go converter. So, yeah, kind of like an all-in-one, like, whatever you have. If it's got a bunch of LiPo batteries, this charger will probably do the right job for you. All right. Everybody likes this and everybody wants this. It's a great chip and it's in stock. It's not expensive. It's a couple bucks. Here's the part number. If they want to search, they can, you know, read this here, but you could also probably just search for... The BQ25792. So it's in stock, which, again, I'm trying to only suggest things in stock. They have a couple thousand stock. I'm definitely going to pick some up. It's a great chip. It's available in QFN. It's not too hard to put together. It's non-BGA and not too many pads and not too many connections. Like, it's very, it's bare bones. It's spare, but it's very complete. Thank you.