_

+

Internal

Termination at 50 Ω

DVI-Compliant Cable

DATA

DATA

TI TFP501 Receiver

TI TFP510 Transmitter

Current

Source

a ) Single-Ended Input Signal

b) Differential Input Signal

TFP501

www.ti.com

SLDS127C

– JULY 2001 – REVISED JULY 2011

TFP501 TMDS INPUT LEVELS AND INPUT IMPEDANCE MATCHING

TFP501 is internally optimized using a laser trim process to precisely fix the single-ended termination impedance

at 50

Ω. This fixed impedance eliminates the need for external termination resistors while providing optimum

impedance matching to standard DVI cables having a characteristic impedance of 100

Ω.

Figure 14 shows a conceptual schematic of a TFP510 transmitter and TFP501 receiver connection. The TFP510

transmitter drives the twisted-pair cable via a current source, usually achieved with an open-drain type output

driver. The internal single-ended termination resistors, which are matched to the characteristic impedance of the

full differential signal is shown in Figure 15. The TFP501 is designed to respond to differential signal swings

Figure 14. TMDS Differential Input and Transmitter Connection

Figure 15. TMDS Inputs

TFP501 MODES OF OPERATION

The TFP501 provides system design flexibility and value by providing the system designer with configurable

options or modes of operation to support varying system architectures. The following table outlines the various

panel modes that can be supported along with appropriate external control pin settings.

PANEL

PIXEL RATE

ODCK LATCH EDGE

ODCK

DFO

PIXS

OCK_INV

TFT or 16-bit DSTN

1 pixel/clock

Falling

Free run

0

0

0

TFT or 16-bit DSTN

1 pixel/clock

Rising

Free run

0

0

1

TFT

2 pixel/clock

Falling

Free run

0

1

0

TFT

2 pixel/clock

Rising

Free run

0

1

1

24-bit DSTN

1 pixel/clock

Falling

Gated low

1

0

0

NONE

1 pixel/clock

Rising

Gated low

1

0

1

Copyright

© 2001–2011, Texas Instruments Incorporated

13