USB 2.0
Controller
Like any integrated circuit the controller will need some peripheral components to make it run properly
Crystal
Keep the XTAL as close as possible to the IC. Where applicable connect the XTAL housing to GND. A via fence reduces coupling to the GND plane. An oscillator can be used alternatively.
Load Capacitor
Load capacitors should be low leakage and stable across temperature range (NP0). For the capacitive load (cload) the stray capacitance of the PCB and the IC pins should be considered:
CL = (C1*C2) / (C1+C2) + Cstray
Cstray ≈ 3…6pF
Common Mode Filter
On differential datalines, a CMC filters common mode noise without affecting the useful signal.
Filter Capacitor
Keep DC-Bias and SRF in mind when selecting MLCCs for filtering.
DC Filter
The filter for VCC can have rather high impedance because there is no signal to take care of.
DC Filter
The filter for VCC can have rather high impedance because there is no signal to take care of.
ESD Protection
ESD protection devices should be put right behind the connector. Avoid layer hops to prevent propagation of the ESD.
USB 2.0 Connector
Select SMT, THT or THR types for optimized processing. Check for high current types or short types to fit your needs. Furthermore we can support you with USB connector types like A, B, Mini and Micro in multiple orientations.
Integrated USB 2.0 Jack
The WE-EPLE is a USB 2.0 jack that comes with a complete integrated filter circuit.
XTAL Ground
This GND plane should be connected to IC GND and cover all the traces to the XTAL.
Short Introduction to USB 2.0
The USB interface is probably the most widespread interface in the world, both in domestic and industrial environments. The USB 2.0 standard is a serial bus system with a maximum data rate of 480 Mbit/s.
Despite its widespread use, there are some points to consider when designing the application in order to achieve an EMC-compliant interface. Using suitable TVS diodes and current-compensated common-mode chokes for data lines, effective concepts can be developed to obtain non-critical circuits.
