OG_MU4-USBIF_v10e 14 Circuit Design, Inc.
OPERATION GUIDE
When designing an original USB interface system similar to the MU4-USB using the MU-4, bear in mind the items
explained below.
Although the circuit diagram shown in this operation guide is a proper circuit, even when made in accordance with
the circuit diagram, it may not perform well due to high frequency noise from the surrounding circuitry.
Bear in mind the following when designing circuits.
1. Exercise caution in placement of the MU-4 and USB chip. In addition, there are cases where shielding is
necessary around the chip.
2. Add a noise filter to the USB interface signal wire.
3. Ensure a sufficiently large ground pattern for the MU-4. In addition, provide shielding for the signal wire too.
Use a double shield USB cable (USB 2.0 High Speed).
In order to assess the performance of your circuit boar
d, issue the ‘@RA’ command to acquire the RSSI level of the
MU-4 and check the level. It is necessary to acquire and assess the level of all the channels. Set a standard lower
than the value acquired with the MU4-USB. Here it is convenient to use the air monitor of the MU-4 evaluation
program. In order to use the air monitor function, it is necessary to make a design in which the terminals of the MU-4
can be controlled from the outside.
If you design an original system with a USB interface, you will need a unique vendor ID. Vendor IDs are obtained
from USB-IF. For details, refer to the site below.
USB-IF website URL: http://www.usb.org/developers/vendor/
When you have a vendor ID, you can write it to the chip using an EEPROM programmer (MProg or the like) provided
by FTDI.
In addition, although you can use the FTDI USB driver, it is necessary to change several of the driver related files in
order to make the driver proprietary
.
Edit the Ftdibus.inf, Ftdiport.inf and Ftdiun2k.ini files in the driver folder to make
them apply to your company.
Chapter 6 When Designing an Original System
6.2 The USB Driver
6.1 The Circuits
