Philips MIIC-201D/U Network Card User Manual


 
7
compatible, not SMBus compatible. Some features of the SMBus protocol not
supported include time-outs, device reset, and Packet Error Check byte processing.
The non-supported SMBus features may, or may not, permit the use of the I
2
C
adapter in your SMBus application. Consult the MCC FAQ web page and SMBus
Specification for details.
4 ESD (Electrostatic Discharge) Precautions
Electrostatic discharge is defined as the transfer of charge between bodies at
different electrical potentials. Electrostatic discharge can change the electrical
characteristics of a semiconductor device, degrading or destroying it. Electrostatic
discharge also may upset the normal operation of an electronic system, causing
equipment malfunction or failure.
When connecting the I
2
C adapter to a host computer and a target system, extreme
care must be taken to avoid electrostatic discharge. Failure to follow ESD protection
procedures when using the I
2
C adapter could damage the host computer, I
2
C
adapter, or the target system, and void product warranty coverage.
4.1 Host Computer Grounding
Case 1 - Desktop and Single-board Computers. The chassis on a desktop or
single-board host computer must be connected to earth ground to comply with
safety regulations. If the computer chassis is NOT connected to earth ground for
some reason (i.e., use of a two-prong power mains plug), the host computer power
supply ground will float to some unknown voltage potential.
Case 2 - Laptop Computers. Laptop computers present special ESD problems. Most
laptop computers use an external double-insulated mains power supply which is
NOT connected to the mains earth ground. This means that the laptop chassis is
floating at some unknown voltage potential.
In either case, upon connection to the I
2
C adapter and the target system, the host
computer will discharge energy through its serial port to the I
2
C adapter, and on to
the target system. This discharge could damage the host computer, I
2
C adapter, and
the target system.