LDO & Linear Regulators: New Product Announcement
Learn about TI’s latest LDOs and Linear Regulators in this short overview. Featuring the next generation of ultra-low power LDOs with enhanced analog performance and a one of kind Smart AC/DC Linear Regulator, TPS7A78.
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Hi, everyone. As Rob mentioned, today we'll be going over a quick overview and product update for LDOs and linear regulators. As you may well know today, TI is one of the premier linear regulators and LDO suppliers. And with that, we definitely spend a lot of time improving our portfolio in different performance areas, which I'll go over in a little bit.
But first, let me talk to you about our agenda today. First and foremost, the overview. Second, we'll be going over some key product updates, including our ultra-low IQ or ground current consumption portfolio, the new smart AC/DC linear regulator that we just released, and the next generation of linear regulators coming out of our workshop.
I'll also take a little bit of time at the end here to talk about the new tools and technical documentation available on TI.com. And all of this information you can find on our website today if you go to TI.com/LDOs.
As I mentioned earlier, TI has one of the most comprehensive portfolios for LDOs, with over 500 devices. When we say devices, these are generic part numbers, not orderables. When you look at different orderables for different output voltage configurations, packages, operating temperatures, we have over 5,000 different parts, and growing. So a very large portfolio that we have here over the years. And we've been working on this industry for more than 40 years.
The way we look at these devices is by product performance families. So we have our low noise, high current family. We have our automotive-rated LDOs. The traditional lin regs devices that a lot of people are used to, like the 1117s and UA78 devices. And then we have our general purpose family.
Our general purpose family is anything that doesn't fit into these previous buckets, but they're still very good linear regulators. And we'll talk about them here a little bit further on. Today, as I mentioned, I'll be going over the low IQ, which is one of our key performance vectors. We'll go over the new lin regs, as well as the high voltage side.
So with that said, let's get started on low IQs. What we've done here is we set out to improve the standby power consumption of our LDOs without sacrificing the analog performance. So we wanted to create LDOs that are very good for battery operated applications or applications that have very strict power efficiency consumptions, and improve the analog performance or the performance of our LDOs. Typically, you would see this in applications like IoT, smart door locks, power tools, et cetera.
So what we set out to do was three key performance upgrades. Number 1, improve our load regulation and response time. Number 2, improve the current drive and integrate supervisor circuitry to these LDOs. And number 3, enhance that efficiency and reduce dropout as much as possible.
So we'll get started here with improved load regulation. Our latest release the TPS7805 is our hero product for very good load regulation and fast transient response. This is a one microamp typical operation LDO with a recovery time of 50 microseconds or less for a transient of one milliamp to 100 milliamps.
And you can see this on the chart here below. You can see the LDO recovers from that spike within that 50 microsecond window. This is particularly helpful if you're powering an MCU, like an MSP430. But at the same time from that same rail, you want to power a wireless communication chip like a Bluetooth or a sub-one gigahertz transmitter.
Next up, we have our high voltage, high current variant. This is the TPS7825 and TPS7826. These are 2.5 microamp consumption LDOs, but they can perform up to 18 volt operation with integrated supervisor circuitry in the same package and a 1% accuracy over temperature.
Key design challenge that we're going after here was supplying a low standby power based off a battery or a high efficiency concern. But in these systems you would need a bit of a kick. You would need the system to wake up, supply a little bit more current, and still be able to go back down and keep that high efficiency.
And this is where this family of 300 milliamp and 500 milliamp LDOs are very helpful. As you can see down below on the chart, very similar transient response we were going after. Although the recovery time here is a little bit longer, that peak is well contained within the 200 millivolts, well within the 1% accuracy over temperature for this device.
And last but not least, we have our TPS7810. This is an enhanced efficiency, very low dropout LDO. This is an NMOS architecture that requires a biased pin going into the LDO. So if today you're using a DC to DC, a buck regulator, going out from your battery, you can use this LDO to clean up that rail for sensitive digital rails or anything with wireless or a sensitive analog. But keep that efficiency very high.
You can see the dropout chart here across the current performance of this device, dropout is always below that 60 millivolt rating. So you get a very, very low dropout. However, PSR still remains high. Across frequency operation, you can see that ripple rejection stay above 40 dB all the way up to 100 kilohertz.
So this is a very good device to keep in mind if you're using buck regulators or DC-to-DCs and audio applications, anything with Bluetooth, wireless communications, or if you just need to clean up the rail after the DC-to-DC and keep your efficiency high. All these three products were recent releases. You can find more information on our website. And each one of these have TI designs tied to them where you can see the inherent benefits of their operation.
Now I want to shift gears into something that's entirely new and a one-of-a-kind release from TI. This is a smart AC/DC linear regulator. This is a integrated power supply or regulator for the next generation of AC-to-DC. So if you have an application today where you're using AC-to-DC power supplies, anywhere less than 600 milliwatts of power consumption, this is one way you can power your system while avoiding magnetic components and keeping that power supply noise very low.
Key takeaways from this-- this is very high efficiency. We're able to achieve of up to 75% efficiency with just a purely linear power supply. You can reduce your power consumption on standby by up to 75%. So this can perform in single digit milliwatt standby power consumptions.
And then in terms of size, this is relatively small. We're talking about taking away 26 different discrete components. You don't need a bridge rectifier or rectifying diodes to be able to power this device.
And you can use this in a myriad of applications. Think of small appliances that require very little power, have a small actuator, IoT and lighting applications where you can tap off the AC line going through, say, a building, factory automation, going down the line where you can have a remote or a field transmitter, and of course grid and anything that's solar power, wind power, where you can directly tap off the AC line and use this device to power your MCU or the rest of the board.
So how this works is an integration of three main steps. First and foremost is an active bridge control where we can clamp the AC voltage going into the device, rectify that, and make it a DC voltage.
Second stage is a four-to-one switch cap, which takes the input voltage given here, divides it by four. This is particularly useful if today you're doing a cap drop power supply, this stage right here can reduce your capacitor component by a fourth of its value and also help us maintain the high efficiency.
And finally, we have the integrated LDO with integrated safety features, including power good, which is supervisory circuit, and power fail to detect whenever that AC line goes below acceptable voltage conditions.
So the question here is what makes this smart. And we get this question a lot, and really what makes this smart is the integration of all of these features combined makes it for more efficient performance. For example, let's say you have a five volt regulated output that you need for the LDO. What that's going to do is it's going to signal to the switch cap the LDO needs at least a 5.5 or so to keep that efficiency high and regulation stable. And the switch cap is going to then regulate the SCN to four times that value, so 22 volts.
And that's going to signal to the control logic, we need to keep the input capacitor to drop to the 22 volts needed. And it'll continuously measure that and continue to regulate itself in order to keep efficiency high and regulation stable. You contrast that to an existing cap drop solution where most of the regulation is constant, dropout is always there, you're always losing power. This can help make that a lot more efficient.
So if you look at this device today, we don't have a maximum AC rating. The AC rating is as high as you can find the input capacitor over here. The device itself is rated for 23 volts AC upwards to 30 volts AC. So you could use this off with a 24 volt AC loop without the need for an input cap. But if you want to use it out of 120 volts, 240 volts, then you need to properly sized that cap drop value and resistor value at the front.
As I mentioned, efficiency can reach all the way up to 75% here. Here's a typical operation graph for 30 milliamp loads. As you can see, going off from five milliamps all the way up to 30, you can get to that 75% efficiency very quickly. So if you're hovering between this operation here you, can achieve very high efficiencies with this linear power supply.
Device is available today at 3.3 and five volts. However, the internal LDO is configurable in 50 million all steps. So you will be seeing more voltage options in the future, including 3.6 volts, 2.8, 1.5, 1.25, and so forth.
And today in order to speed up your design, we have a couple of tools that we've developed. There's a lot of technical content on our website. If you go to TI.com/TPS7A78, you'll find a lot of this information collected. But some of the ones that stand out are this one phase shun e-meter design. It's entirely powering that shunt metrology from that AC/DC smart linear regulator.
At the same time, we also have standalone power supplies that we've designed for general use cases. This one is for a 100 milliamp power supply. It's an offline non-isolated AC-to-DC power supply.
And we also have our EVM or Evaluation Module. This board is pre-configured for many different applications. If you go to the user guide, you would find the layout, BOMs, and component descriptions from multiple different configurations to 40 volts, 120 volts, 480 volts, et cetera. And the layout has enough footprints for you to switch out the components to be able to size to your desired application.
One final piece that's coming out here very soon in the next couple of weeks is this design calculator. This is a software developed to help calculate everything needed for this device. You can find all this information in tabular form today on the data sheet.
But we wanted to make this a little bit easier. So this tool can help you select different configurations, whether it's half bridge, full bridge, three phase power, et cetera, and be able to create the necessary BOM and calculations in terms of efficiency, operating frequency, standby power, all of that good stuff into one single tool. So this will be available on TI.com soon enough.
Moving on, I want to shift gears here and talk about our upcoming linear regulator family. This is a family of devices, the TLV76, TLV75 family of products where we're taking the popular and very useful 1117 function and enhancing it for the future. So if today you're using any of these regulators, we've gone through lengths to make sure that the next generation is not only as easy to use, but also has enhanced features to them.
For example, the TLV1117 is our high voltage version of this family. Today, we're moving to the 767 for improved performance in lower standby power consumption. So that IQ goes from five milliamps to 50 microamps, offering smaller sizes for anybody who has space constrained applications. We now have a two-by-two package with a thermal pad on there. So we didn't sacrifice on thermal dissipation, but we did get big improvements in package size.
We've added protection features such as fullback current limiting and reduced in-rush consumption. We've reduced the dropout voltage at 100 milliamps or even higher going from the one volt requirement of the 1117 to around 140 millivolts. And of course, we now have output voltages for the next generation of digital controls. Anything less than a volt, around the volt, that is now possible with this new family.
We also have similar flavors at the five volt level with the TLV757, 758, 759, and 755. And on this family we have two different flavors of output currents-- 500 milliamps and one amp of output. But same message, same tactic is improved performance, smaller size, lower dropout, and lower output capability.
One inherent feature that we get across this family is reduced in-rush consumption. If you're powering a really large capacitor today, for example, 22 microfarads at the output, you'd typically see a very large current spike at the startup of the LDO. This new family cuts off that consumption with in-rush control, making sure that that current does not exceed the desired output while it's powering up. Once you see we can get to that 90% of the output voltage required, that LDO is already down to minimal consumption, ensuring nothing goes wrong in the output.
Here's the chart for a fullback current limit. Fullback current limit is a limiting factor for power dissipation. That way when you exceed your maximum current, you're not outputting too much power, and that power dissipation stays rather low, making sure that the device does not go into thermal overload.
If you need that protection feature for your design, this is a very good feature to keep in mind, particularly from anything that's portable or anything that has human contact, you do not want those applications to get too hot. This is something that we highly, highly recommend.
Final here, not least is our tools and technical documentation on TI.com. We've created an updated series we call the LDO basic series. This is a collection of videos, blogs, and e-books covering all major specs of LDOs and key design questions. Of course, we have our E2E blogs, we have our application engineers supporting you on E2E. But we wanted to collect all of our commonly asked questions, any misconceptions, anything to clear that up in a more of a self-help guide and self-help collection of collateral for everybody.
We have our LDO universal EVM. This EVM is designed to fit in our most commonly used LDOs. Anything you've seen here presented today fits into this EVM. And you can use this as a test hub for most of the parts that we've been releasing in the last couple of years.
And the last addition to our tools family here is the LDO thermal calculator. If you've worked with Webench before, you've seen that Webench has a thermal simulation tool to them. Well, now we have a thermal simulation tool for LDOs where you can pick your operating conditions, pick the package, and it will calculate everything for you.
And it will give you this curve of effective operating temperature based on PCB copper area coverage. So today we had this information on our data sheet. You can go find the package thermal resistance and do that estimation.
We've taken that a step further, and now we can give you an active feedback and an active chart based on your copper area and design considerations. So you will see this showing up on our product folders. If you go to our product folder today, you'll see this tool show up on the right side. And it's widely available for the most common parts. And you'll see more and more parts showing up in the future.