Inkjet printers operate by propelling variably-sized droplets of liquid or molten material onto almost any printable material. They are the most common type of computer and consumer printer due to their low cost, high quality of output, capability of printing in vivid color, and ease of use. There are three main technologies used in contemporary inkjet printers: thermal, piezoelectric, and continuous. Desktop inkjet printers, as used in offices or at home, all use aqueous inks. These inks are inexpensive to manufacture, but are difficult to control on the surface of media, often requiring specially coated media and sensors to control the quality and position of them. Inkjets can print finer, smoother details through higher print head resolution, and consumer inkjets with photographic-quality printing are widely available. Inkjets have the advantages of practically no warm-up time and lower cost per page. To keep overall printing costs low, efficient power supplies and intelligent power management such as fast wake-up and auto-power-off are essential.
Notebook computer design is separated into two segment: Power and Hardware. The Power Segment involves hardware device power sources. For power sources, using a switching mode is an excellent way to improve converter efficiency. High current is its key feature. Power sources that use this technology include CPUs, DDR systems, chipsets, chargers, and VGA power sources. Low-dropout linear power is another solution for converter efficiency. Its main benefits are lower prices and simple circuitry. The Hardware Segment can be regarded as a non-power segment. Types of hardware include SD cards, USB ports, fingerprint recognition sysyems, remote controls, audio controls, touchscreens and touchpads, ambient light sensors, S-video ports, and wireless transmission sysytems such as IrDA and Bluetooth. Some of these need similar functions such as ESD protection, current limiting, and load switching. Different solutions based on different specifications are suggested.
Switch Mode Power Supply (SMPS) applications generally involve power adaptors, desktop power, or server power. SMPS design is separated into primary and secondary sections due to isolation topology. The primary section involves EMI filtering, input rectification, and power factor correction (PFC) devices. The most important design concept is PFC to improve efficiency. Good performance of a PFC rectifier enables the power supply to operate efficiently under a light current load. Ultra-fast recovery time of the rectifier and low Qg of the switching MOSFET are the most important factors associated with PFC. No matter what kind of topology is involved, PFC is the key not only to increasing efficiency, but also to improving thermal performance, especially for 80-plus SMPS. For EMI, film capacitors and ceramic disc capacitors are good for X-capacitor and Y-capacitor design, respectively. Regarding input rectifier devices, single-phase bridge rectifiers are the best solution, especially for power adaptors. The secondary section includes output rectifiers and filters. Trench MOS Schottky technology is a new technology that can replace planar technology as a non-synchronous rectifier solution. Its key feature is ultra-low forward voltage, or Vf. Trench MOS Schottky rectifiers work well as output rectifiers, especially in multi-output systems. In addition to providing good forward voltage performance at high ambient temperature, they also feature high current handling and voltage (up to 150 V) capabilities. Different solutions are based on different specifications.
A tablet PC is a tablet-sized computer that also has the key features of a full-sized personal computer. Tablets are much thinner, lighter, and more power-efficient than conventional notebook computers. They are equipped with a rotatable touchscreen as an additional input device, and run a standard PC operating system like iOS, Windows, or Android. The user interface generally does not include a conventional keyboard and uses the display as a multifunction input and output interface. The hardware architecture of tablet PCs is similar to that of notebook computers, except that it handles much less power and generally has height and size restrictions. High efficiency at various load conditions provides the ability to overcome thermal challenges to help achieve miniaturization. Vishay offers leading-edge technologies to help with this efficiency improvement, as well as help to improve battery life and overall system performance.
