TMDS261B Datasheet, PDF (10/48 Pages) Texas Instruments – TWO-PORT HDMI SWITCH

TMDS261B
SLLS987A – SEPTEMBER 2009 – REVISED JULY 2011
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DEVICE POWER
The TMDS261B is designed to operate from a single 3.3-V supply voltage. The TMDS261B has three power
modes of operation. These three modes are referred to as normal mode, standby mode, and low-power mode.
Normal mode is designed to be used during typical operating conditions. In normal mode, the device is fully
functional and consumes the greatest amount of power.
Standby mode is designed to be used when reduced power is desired, but DDC and HPD communication must
be maintained. Standby mode can be enabled via the I²C interface (See Table 8 through Table 11) or GPIO
interface (See Table 1). In standby mode, the high-speed TMDS data and clock channels are disabled to reduce
power consumption. The internal I²C logic and DDC function normally. HPD[1:3] follow HPD_SINK.
Low-power mode is designed to consume the least possible amount of power while still applying 3.3 V to the
device. Low-power mode can be enabled by either the LP pin or by local I²C (See Table 8 through Table 11). In
low-power mode, all of the inputs and outputs are disabled with the exception of the internal I²C logic and LP pin.
The clock-detect feature in the TMDS261B provides an automatic power-management feature in normal mode. if
no valid TMDS clock is detected, the terminations on the input TMDS data lines are disconnected, and the TMDS
outputs are high-Z. As soon as a valid TMDS clock is detected, the terminations on the TMDS data lines are
connected, the TMDS outputs come out of high-Z, and the device is fully functional and consumes the greatest
amount of power.
ELECTRICAL CHARACTERISTICS
over recommended operating conditions (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN TYP MAX UNIT
I_CC
Normal-mode supply current
LP = HIGH, TMDS: V_ID(pp) = 1200 mV, 3 Gbps TMDS data
pattern; HPD_SINK = HIGH, S1/S2 = LOW/HIGH, HIGH/HIGH
170 216 mA
I_STBY Standby supply current
LP = HIGH, TMDS: V_ID(pp) = 1200 mV, 3 Gbps TMDS data
pattern; HPD_SINK = HIGH, S1 = HIGH, S2 = LOW
3 5.5 mA
I_SD
I_NCLK
Shutdown current
Normal-mode supply current,
with no active TMDS input
clock
LP = LOW
LP = HIGH, No TMDS input clock, HPD_SINK = HIGH, S1/S2
= LOW/HIGH, HIGH/HIGH
300 555 μA
12 18 mA
HOT-PLUG DETECT
The TMDS261B is designed to support the hot-plug indication to the input ports (HDMI/DVI sources connected to
TMDS261B) via the HPD[1:2] output pins. The state of the hot-plug output of the selected source follows the
state of the hot-plug input (HPD_SINK input pin) from the sink side. The state of the hot-plug output for the
non-selected source goes low (See Table 1).
The maximum V_OH of the HPD depends on VCC. It is recommended that if V_OH greater than 3.6 V is needed on
HPD, then an external circuit can be used to drive the V_OH from the 5 V of the HDMI source (connected as
shown in Figure 45).
ELECTRICAL CHARACTERISTICS
over recommended operating conditions (unless otherwise noted)
PARAMETER
TEST CONDITIONS
V_OH(HPD)
V_OL(HPD)
I_H
I_L
R_L
High-level output voltage
Low-level output voltage
High-level input current
Low-level input current
Output source impedance
I_OH = 100 μA
I_OL = 100 μA
V_IH = 2 V, VCC = 3.6 V
V_IL = 0.8 V, VCC = 3.6 V
MIN TYP
2
0
–10
–10
800 1000
MAX
VCC
0.4
10
10
1200
UNIT
V
V
μA
μA
Ω
10
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