Overview of the world’s first true single-chip wireless power transmitter (P9030), and the world’s highest-output-power single-chip receiver solution (P9020). This silicon-based IC solution facilitates the design of wireless power (electromagnetic inductive) charging bases and wirelessly powered battery charging on mobile devices. The highly integrated multi-mode transmitter reduces board footprint by 80 percent and bill-of-materials (BOM) cost by 50 percent compared to existing solutions. Designed to be WPC Qi-compliant, both devices are capable of “multilingual” (multi-mode) operation, supporting both the Qi standard as well as proprietary formats for added features, improved safety, and increased power output capability. Demonstration presented by Jack Deans, Field Applications Manager at IDT. Visit http://www.idt.com/products/power-management/wireless-power .
Hi, I’m Jack Deans, Field Application Manager for Integrated Device Technology. We have developed a highly integrated wireless power solution making the design effort easier than ever before while adding many safety features.
Our solution uses magnetic induction to transmit power. The upper left graphic simply shows alternating current applied to one coil generates an alternating magnetic field that the second coil picks up. If that second coil is well-aligned and in close proximity, less than a centimeter or so, then we can transmit power efficiently across that gap. The second graphic in the middle shows those two coils separated by a small distance but now sandwiched between two ferrite shields. These shields are thin and just larger than the coil, and hold that magnetic field between those two shields. I’ll show you an example of a WPC compliant coil in a few minutes.
The next graphic is a simplified system block diagram. I’ve already explained the alternating magnetic field, but there’s another complexity to the system needed for safety and increased efficiency. Notice the yellow arrow in between the receiver and the transmitter. To keep the system stable, a communications method was developed to allow the receiver to tell the transmitter just how much power to deliver. That communications method is accomplished by the receiver modulating its load. Then the transmitter detects that change in load and simply demodulates the digital information stream. The blue arrow shows a reverse communications path that IDT allows, which can open up various application scenarios. For instance, if only certain authorized receivers are allowed to charge on a charging pad, then a query can be established. If you want to enable higher power transfer than the Qi standard allows, then both sides can negotiate that fact. Other scenarios are enabled through by communications as well. Before I show you our transmitter eval kit, let’s review the features and benefits of our transmitter IC.
Shown here are the functional blocks within the transmitter. To note, this device was designed for WPC compliance and due to its programmable internal micro-controller it is flexible enough to handle future modifications to the WPC’s specification. Shown below the functional block diagram are two transmit coil examples. The coil on the left is a TXA1 coil, and you can see the magnet in the center to attract the receiver. In a free positioning arrangement shown on the coil arrangement on the right we can choose which coil has the best coupling and then only use that coil for power transfer. That gives a wire charging zone. Foreign object detection is another key feature. IDT takes that foreign object detection over and above the WPC specification by also detecting if metallic foreign objects slides in between the two coils during power transfer. If that occurs and the object is above a programmable threshold, we will cut power transfer.
Here is a picture of our transmitter evaluation kit. Also, I’m holding one in front of the camera as well. You can see our component with its needed discreets around it take up a board space of less than 350 square millimeters. Above the coil is a plastic shield. This one is about two millimeters thick, and the coil sits on top of a fairly thick, in this case, ferrite shield. There’s a reset button, power input, and an I2C connector as well. We use a USB to I2C connector to connect a laptop or a desktop to our transmitter IC for debugging and evaluation purposes. Here’s the IDT wireless power receiver IC.
It also has an embedded micro-controller giving it the flexibility to adjust to various application and design needs. Up to 7.5 watts is available to the load through an efficient synchronous buck converter. Shown below the graphic are multiple styles of WPC compliant coils. Our receiver is designed to use all types of WPC compliant coils. Here’s an example of a coil. It comes as a module, and this one’s about a millimeter thick, a copper wound coil on top of a ferrite shield. Our receiver wireless power development kit looks like this. It’s a PCB mounted on top of a coil and we left a gap in there so you could put a battery or some other object that might be related to your design, to see how that affects power transfer. Down here is a load that, in this case, we put on a five-watt load. There’s a USB interface, and there’s a series of LEDs that tell you communication status and whether there’s any foreign object detected. Use a USB to I2C chip to allow an external processor or laptop, desktop, to communicate with our chip for development purposes.
And to support that, here is the screenshot of our development GUI software we provide our customers. This GUI tool is configurable but shown here is a transmitter coil current and AC frequency over time. In this case you can see the transmitter was pinging the receiver, and once communication was established the receiver communicated its desired power level and the transmitter responded accordingly. If the log messages box on the lower left was checked, you would see the live stream, a digital communication between the receiver and the transmitter, in the text box below. This is a powerful and useful tool, making your development effort easier and more efficient. Also making your effort easier and more efficient are IDT’s field applications engineers and factory apps engineers. Our engineering support is worldwide and world class.
Please contact your local IDT sales representative for a demonstration of IDT’s wireless power solution.
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