Agilent 5988-6219EN USB 2.0 Compliance Testing with Infiniium Oscilloscopes - Application Note c20140820 [16 free download

File name 5988-6219EN USB 2.0 Compliance Testing with Infiniium Oscilloscopes - Application Note c20140820 [16

Keysight Technologies USB 2.0 Compliance Testing with Infiniium Oscilloscopes Application Note Introduction Universal Serial Bus (USB) burst on the scene in 1995 delivering Who Should Read This a revolutionary way to connect personal computers and devices. Application Note? Allowing hot-plug capability, USB has introduced ease-of-use to Digital designers and developers the PC device market by providing a simple connection scheme working towards USB 2.0 compliance. and protocol for a wide variety of computer devices, ranging from keyboards and mice to high-bandwidth devices such as printers, scanners, and cameras. Table of Contents USB has now successfully replaced aging serial and parallel ports as the connection of choice for both device manufacturers Introduction . . . . . . . . . . . . . . . . . . . . . .2 and end users. Whereas cable length and device expansion Basic Specifications . . . . . . . . . . . . . . .3 were limitations with older serial and parallel connections, they Full/Low-Speed Test Suite . . . . . . . . . .4 are no issue for USB. Amazingly, it allows devices to exist up to Full/Low-Speed Test Fixture. . . . . . . . .4 30-meters away from the host, and allows up to 127 devices to Signal Quality Test. . . . . . . . . . . . . . . . .5 be connected to a single host and port at once through a series of USB hubs. The ability to talk directly to devices or to devices In-Rush Current Check . . . . . . . . . . . . .7 through hubs allows for this incredible expansion capability. Droop and Drop Testing . . . . . . . . . . . .8 Back-Drive Voltage Test . . . . . . . . . . . .9 USB 1.1 worked best for slower human-interface devices such as Hi-Speed Electrical Test Suite . . . . . . .9 mice and keyboards, with low-speed operating at 1.5-Mb/s and Hi-Speed Electrical Test Tool . . . . . . . .9 full-speed operating at 12-Mb/s. Higher-bandwidth devices were Hi-Speed Test Fixture . . . . . . . . . . . . .10 severely limited by these relatively slow data transfer rates. As a Hi-Speed Signal Quality Test . . . . . . .11 result, the USB-Implementers Forum (USB-IF) introduced the fully backward compatible USB 2.0 in May 2000, which resulted in a Monotonicity . . . . . . . . . . . . . . . . . . . .11 40-fold increase in data throughput for hi-speed over full-speed. Packet Parameters Test . . . . . . . . . . .12 USB 2.0 operates a