Power Traces In some situations, it is not necessary to dedicate a power plane to a voltage rail, for example, a limited run of a 5-V or V power trace. Control power supply ramp-down with a bleed resistor. Load capacitors of 12 pF are required between each crystal pin and ground. Cypress reserves the right to make changes without further notice to the materials described herein. Keep this resistor close to the USB connector. A USB device responds by entering a low-power state and monitoring the bus for activity to resume operation.

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The resonator is a small package, which also reduces the external part count.

Guide to a Successful EZ-USB® FX2LP™ Hardware Design

This very usefully separates hardware checkout from firmware debug. Excessive data jitter would make the purple lines fuzzy, with some of them touching red.

Figure 8 illustrates a problem with this simple circuit for a bus-powered device the overwhelming majority of USB devices. This prevents the solder from wicking through the holes during the assembly process.

B. USB Device – Cypress EZ-USB FX2LP CY7CA API Reference

These dimensions are crucial to get a precise PCB layout design. Some FX2LP systems may use a coprocessor.

Then select the box for Delete the driver software for this device and click OK Figure This tab can be used to schedule individual USB transfers in and out of your device and to check the results. However, the hot plug feature places special demands on the circuit used to reset a USB chip. Recent developments in lower cost resonators with included load cevice make them usable as USB clock sources.

A microstrip has an impedance,that is determined by its widthheightdistance to the nearest copper planeand the fz2lp permittivity of the material commonly FR-4 between the microstrip and the nearest plane. You can remove this association by right-clicking the device in Device Manager and selecting Uninstall. Some experimentation may be necessary to obtain the correct value. In rare cases, the gx2lp may be associated with a wrong device.

CN105760182A – FX2LP USB controller based FPGA configuration device – Google Patents

Use ceramic or tantalum capacitors. Keep power traces short. USB peripherals typically regulate this voltage down to 3. Cypress does not assume any liability arising out of the application or use of any product or circuit described herein.


Stringer Stringers are interconnecting segments that electrically connect via capture pads and surface land pads. Use the Schematic Review Checklist to help confirm that design requirements are met. For backwards compatibility, devices that are highspeed capable must be able to communicate with full-speed USB products at 12 Mbps using 3. Removing an Old Driver 8. Their functions are described in Table 4. Generally, there are two different surface land pad designs: Components choke, resistor, and so on are not connected to the USB data lines; such connection is not recommended as it can cause signal quality issues.

This problem can be caused by the hardware issues mentioned in previous sections. Although it is no substitute for a full USB bus analyzer, it does provide some of the basic debug features of an analyzer. If designing a bus-powered solution, employ a softstart circuit so all of the capacitance is not filled at once.

Differential impedance,is measured by measuring the impedance of both microstrips and summing them. This is achieved by routing signals on various numbers of PCB layers. The copper surface of the land pad is completely exposed, which provides a greater area for the VFBGA solder ball to adhere. Common mode chokes typically provide little benefit for high-speed signals and can adversely affect full-speed signal waveforms.

Whichever voltage you choose, be sure to test it thoroughly see the Testing section. This previously made USB device no code required simplifies the USB checkout of a new design by removing any user code issues from the initial testing.

The four methods, in order of preference, are: The ball package meets the needs of space-sensitive PCB designs.