DS64MB201 Datasheet, PDF (12/28 Pages) Texas Instruments – DS64MB201 Dual Lane 2:1/1:2 Mux/Buffer with Equalization and De-Emphasis

TXIDLEDO/SO
0
Float
1
TABLE 3. Idle Control (3–Level Input)
Function
This state is for lossy media, dedicated Idle threshold detect circuit disabled, output follows input based
on EQ settings. Idle state not guaranteed.
Float enables automatic idle detection. Idle on the input is passed to the output. Internal 50KΩ resistors
hold TXIDLEDO/SO pin at a mid level - don't connect this pin if the automatic idle detect function is desired.
This is the default state. Output in Idle if differential input signal less than value set by SD_TH pin.
Manual override, output in electrical Idle. Differential inputs are ignored.
TABLE 4. Receiver Electrical Idle Detect Threshold Adjust
SD_TH resistor value (Ω)
Receiver Electrical Idle Detect Threshold (DIFF p-p)
Float (no resistor required)
130 mV (default condition)
0
225 mV
80k
20 mV
SD_TH resistor value can be set from 0 through 80k ohms to achieve desired idle detect threshold, see Figure 5
30076493
FIGURE 5. Typical Idle Threshold vs. SD_TH resistor value
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