PTN3300B_1

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 01 — 8 July 2008

10 of 23

NXP Semiconductors

PTN3300B

DVI and HDMI level shifter

6.1.2 Output Enable function (OE_N)

When input OE_N is asserted (active LOW), the IN_Dx and OUT_Dx signals are fully

functional provided that HPD_SINK input is HIGH. Input termination resistors are enabled

and the internal bias circuits are turned on.

When OE_N is de-asserted (inactive HIGH), the OUT_Dx outputs are in a

high-impedance state and drive zero output current. The IN_Dx input buffers are disabled

and IN_Dx termination is disabled. Internal bias circuits for the differential inputs and

outputs are turned off. Power consumption is minimized.

Remark: Note that OE_N has no influence on the HPD_SINK input, HPD_SOURCE

output, or the SCL and SDA level shifters. OE_N only affects the high-speed TMDS

channel.

6.1.3 DDC channel enable function (DDC_EN)

The DDC_EN pin is active HIGH and can be used to isolate a badly behaved slave. When

DDC_EN is LOW, the DDC channel is turned off. The DDC_EN input should never change

specification).

6.1.4 Enable/disable truth table

[1]

A LOW level on input HPD_SINK disables both the TMDS and DDC channels.

[2]

A HIGH level on input OE_N disables only the TMDS channels.

[3]

A LOW level on input DDC_EN disables only the DDC channel.

[4]

OUT_Dx channels ‘enabled’ means outputs OUT_Dx toggling in accordance with IN_Dx differential input voltage switching.

[5]

DDC channel ‘enabled’ means SDA_SINK is connected to SDA_SOURCE and SCL_SINK is connected to SCL_SOURCE.

[6]

The HPD_SOURCE output logic state follows the HPD_SINK input logic state regardless of Active or Standby mode.

Table 3.

HPD_SINK, OE_N and DDC_EN enabling and power saving functions truth table

Inputs

Channels

Mode

HPD_SINK

[1]

OE_N

[2]

DDC_EN

[3]

IN_Dx

OUT_Dx[4]

DDC[5]

HPD_SOURCE

[6]

LOW

X

X

high-impedance

high-impedance;

zero output current

high-impedance

LOW

Standby

HIGH

LOW

LOW

50

Ω termination

enabled

high-impedance

HIGH

Active

HIGH

LOW

HIGH

50

Ω termination

enabled

enabled

HIGH

Active

HIGH

HIGH

LOW

high-impedance

high-impedance;

zero output current

high-impedance

HIGH

Standby

HIGH

HIGH

HIGH

high-impedance

high-impedance;

zero output current

enabled

HIGH

Standby

with DDC

channel

enabled