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APPLICATION INFORMATION

Supply Voltage

TMDS Inputs

TMDS Input Fail-Safe

TMDS

Receiver

TMDS

Driver

Y

Z

A

B

TMDS341

TMDS Outputs

TMDS341

GND

TMDS

Driver

TMDS

Receiver

TMDS341

SLLS660A – AUGUST 2005 – REVISED OCTOBER 2005

directly to ground to filter supply noise.

Standard TMDS terminations are integrated on all TMDS inputs. External terminations are not required. Each

input channel contains an 8-dB equalization circuit to compensate for cable losses. The voltage at the TMDS

input pins must be limited per the absolute maximum ratings. An unused input should not be connected to

ground as this would result in excessive current flow damaging the device.

TMDS input pins do not incorporate fail-safe circuits. An unused input channel can be externally biased to

prevent output oscillation. One pin can be left open with the other grounded through a 1-k

Ω resistor as shown in

Figure 31.

Figure 31. TMDS Input Fail-Safe Recommendation

A 1% precision resister, 4.64-k

Ω, connected from VSADJ to ground is recommended to allow the differential

output swing to comply with TMDS signal levels. The differential output driver provides a typical 10-mA current

sink capability, which provides a typical 500-mV voltage drop across a 50-

Ω termination resistor.

Figure 32. TMDS Driver and Termination Circuit

output signals are high impedance when OE is high. Normal operation is with both supplies active.

each termination resistor to ground. The terminations consume a total of 10 mW of power independent of the OE

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