Datasheet

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Quick Start Guide

6. Set the output VOD and De-emphasis level.

• For external pin mode control for the VOD and De-emphasis level:

• Set ENSMB = 0 (1kΩ to GND) by using the SW2 (3-2-1) = (ON-OFF-OFF).

• SW4 pin1,2 must be set to the OFF positions, so the SMBUS signals are disconnected.

• Refer to Table 1 for information on the 3 switch settings for the 4 level input.

Example:

• Set DEMB[1:0] with SW5 for the B bank of outputs (top 4 outputs of DS125BR401).

• SW5 (6-5-4), (3-2-1) = (ON-OFF-OFF), (OFF-OFF-ON) = DEMB[1:0] = 0,1 (VOD=1.0V, DE=0 dB).

• Set DEMA[1:0] with SW3 for the A bank of outputs (bottom 4 outputs of DS125BR401).

• SW3 (6-5-4), (3-2-1) = (ON-OFF-OFF), (OFF-OFF-ON) = DEMA1:0] = 0,1 (VOD=1.0V, DE=0 dB).

Table 5. DE and VOD Settings available in PIN MODE

Level EQA/B[1:0] SW1 - EQB[1:0] or SW8 - EQA[1:0] GEN1 and GEN2

Inner Amplitude

6 5 4 3 2 1 DE (dB)

)

1 0, 0 ON OFF OFF ON OFF OFF 0.8 0

2 0, R ON OFF OFF OFF ON OFF 0.9 0

3 0, F ON OFF OFF OFF OFF OFF 0.6 -3.5

4 0, 1 ON OFF OFF OFF OFF ON 1.0 0

5 R, 0 OFF ON OFF ON OFF OFF 0.7 -3.5

6 R, R OFF ON OFF OFF ON OFF 0.5 -6

7 R, F OFF ON OFF OFF OFF OFF 1.1 0

8 R, 1 OFF ON OFF OFF OFF ON 0.7 -3.5

9 F, 0 OFF OFF OFF ON OFF OFF 0.6 -6

10 F, R OFF OFF OFF OFF ON OFF 1.2 0

11 F, F OFF OFF OFF OFF OFF OFF 0.8 -3.5

12 F, 1 OFF OFF OFF OFF OFF ON 0.6 -6

13 1, 0 OFF OFF ON ON OFF OFF 1.3 0

14 1, R OFF OFF ON OFF ON OFF 0.9 -3.5

15 1, F OFF OFF ON OFF OFF OFF 0.7 -6

16 1, 1 OFF OFF ON OFF OFF ON 0.5 -9

NOTE: The De-Emphasis levels are also available in SAS-3 / GEN-3 mode when MODE = 1

SNLU121–November 2012 DS125BR401EVM Evaluation Kit

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