Texas Instruments PanelBus TFP201EVM, User Manual, Page: 9 / 20

TFP201 EVM Board Configuration and Operation
1-3
Overview
1.3 TFP201 EVM Board Configuration and Operation
The TFP201 EVM board is simple to use, requiring only a few steps to operate:
1) Connect power supply GND and 3.3 V V
CC
.
2) Connect DVI input cable from PC (typically 2–3M cable).
3) Connect DVI output cable to monitor (typically 2–3M cable).
4) Power on the supply.
The TFP201 EVM board has various options for different modes of operation,
selectable by jumpers and switches. When shipped, the board is fully opera-
tional and all jumpers are in the default positions.
Note:
When handling board, ESD protection is needed.
1.3.1 Power Supply
A 3.3-V dc power supply is needed to operate the TFP201 EVM. This board
is designed for use with one or two power supplies. Two supplies can be used
if there is a desire to separate power to the TFP201 from the onboard transmit-
ter. If two supplies are used, jumper P14 must be removed; if one supply is
used, P14 must be connected. The default configuration is jumper P14 on.
1.3.2 High-Speed Data Line Probe Point
The high-speed data lines can be monitored on an oscilloscope via the SMA
connectors on the TFP201 EVM. Each data line has a 1-k
Ω
resistor in series
with the SMA connector. This creates a 21:1 test probe point; thus the signal
is attenuated by a factor of 21. This 21:1 probe point is used to compensate
for rise time degradation through scope probes.
1.3.3 Impedance Matching
The TMDS inputs to the TFP201 Receiver have a fixed signal-ended termina-
tion to AVDD. The TFP201 is internally optimized using a laser trim process
to precisely fix the impedance at 50
Ω
. The device will function normally with
or without a resistor on the EXT_RES terminal. The fixed impedance elimi-
nates the need for an external resistor while providing optimum impedance
matching to standard 50
Ω
DVI cables.
1.3.4 Transmitter Voltage Swing
The voltage swing on the transmitter can be adjusted via resistor R21. The
voltage swing can be adjusted depending on the length of the cable being
used. The larger the voltage swing, the better the signal to noise ratio.
1.3.5 Jumper Configuration
Table 1–1 and Table 1–2 reflect the default configuration of jumpers on the
TFP201 EVM board.