User's Manual

Silicon Laboratories Finland Oy
Page 26 of 45
Figure 16: USB_Detach and USB_Wake_Up Signals
7.8 USB Driver
A USB Bluetooth device driver is required to provide a software interface between the chipset and Bluetooth
software running on the host computer. Please, contact Silicon Labs support at http://www.silabs.com for
suitable drivers.
7.9 USB v2.0 Compliance and Compatibility
Although WT41u meets the USB specification, Silicon Labs cannot guarantee that an application circuit
designed around the module is USB compliant. The choice of application circuit, component choice and PCB
layout all affect USB signal quality and electrical characteristics. The information in this document is intended
as a guide and should be read in association with the USB specification, with particular attention being given
to Chapter 7. Independent USB qualification must be sought before an application is deemed USB compliant
and can bear the USB logo. Such qualification can be obtained from a USB plugfest or from an independent
USB test house.
Terminals USB_DP and USB_DN adhere to the USB Specification v2.0 (Chapter 7) electrical requirements.
The chipset is compatible with USB v2.0 host controllers; under these circumstances the two ends agree the
mutually acceptable rate of 12Mbits/s according to the USB v2.0 specification.