PCM-2074 EVB User Manual
SMSC PCM-2074
USER MANUAL
Revision 1.0 (03-31-06)
9
Note:
Each dimension represents a design value. Units are in mm.
8 Operating Conditions
9 Connecting Twisted Pair Cables to the RJ11 Connectors
The PCM-2074 provides two modular RJ11 jacks for connection to twisted pair cables, which need to
be supplied by the user. These cables should have a characteristic impedance of 125 ohms, in order
to match the impedance built into the board. Each end of the twisted pair cable should have a 125-
ohm termination resistor attached.
Recommended cables and terminators:
Single wire type 125 ohm twisted pair cable (ARC-Cab/125T) from SMSC Japan
125
Ω
terminator (ARC-Term/125T) from SMSC Japan
For recommendations on the maximum cable-length, minimum node-spacing, and maximum number
of nodes, refer to the TMC2074 data sheet.
Figure 7.2 Mechanical Specification for the RS485 Board
Table 8.1 Operating Conditions
PARAMETER
SPECIFICATION
Supply Voltage
+5V +/- 5%
Current Consumption
500 mA
Temperature Range
10 to 45C, no condensation
47
47
2
.
6
