DS64BR401 Datasheet, PDF (12/30 Pages) National Semiconductor (TI) – Quad Bi-Directional Transceiver with Equalization and De-Emphasis

Functional Description
The DS64BR401 is a quad transceiver optimized for back-
plane trace or cable interconnect up to 6.4 Gbps. The
DS64BR401 operates in two modes: Pin Control Mode
(ENSMB = 0) and SMBus Mode (ENSMB = 1).
Pin Control Mode:
When in pin mode (ENSMB = 0) , the transceiver is config-
urable with external pins. Equalization and de-emphasis can
be selected via pin for each side independently. When de-
emphasis is asserted VOD is automatically increased per the
De-Emphasis table below for improved performance over
lossy media. Rate optimization is also pin controllable, with
pin selections for 3 Gbps, 6 Gbps, and auto detect. The re-
ceiver electrical idle detect threshold is also programmable
via an optional external resistor on the SD_TH pin.
SMBUS Mode
When in SMBus mode the VOD amplitude level, equalization
and de-emphasis are all programmable on a individual lane
basis, instead of grouped by sides as in the pin mode case.
Upon assertion of ENSMB pins EQx and DEMx functions re-
vert to register control immediately. The EQx and DEMx pins
are converted to AD0-AD3 SMBus address inputs. The other
external control pins remain active unless their respective
registers are written to, in which case they are ignored until
ENSMB is driven low. On power-up and when ENSMB is
driven low all registers are reset to their default state. If
PWDN = 1 is asserted while ENSMB = 1, the registers retain
their current state.
TABLE 1. Equalization Input Select Pins for A and B ports (3–Level Input)
EQ0
F
1
0
0
0
1
1
F
F
EQ1
Equalization Level
Recommended Media Length
F
Off
Bypass
1
5.8 dB at 3 GHz
8 inch FR4 (4-mil trace) or 0.7 meters (30 AWG)
0
9 dB at 3 GHz
12 inch FR4 (4-mil trace) or 1 meters (30 AWG)
F
11.7 dB at 3 GHz
20 inch FR4 (4-mil trace) or 5 meters (30 AWG)
1
14.6 dB at 3 GHz
25 inch FR4 (4-mil trace) or 6 meters (30 AWG)
F
18.4 dB at 3 GHz
35 inch FR4 (4-mil trace) or 9 meters (30 AWG)
0
20 dB at 3 GHz
40 inch FR4 (4-mil trace) or 10 meters (30 AWG)
0
21.2 dB at 3 GHz
10 meters (30 AWG)
1
28.4 dB at 3 GHz
12 meters (30 AWG)
Note: F = Float (don't drive pin), 1 = High and 0 = Low.
TABLE 2. De-Emphasis Input Select Pins for A and B ports (3–Level Input)
RATE
DEM1 DEM0
De-
Emphasi
s Level
(typ)
DE Pulse
Width
(typ)
VOD (typ)
0/F 0
0
0 dB
0 ps VOD: 600 to 1200 mVp-p
0/F 0
1 -3.5 dB 330 ps VOD = 1000 mVp-p
-2 dB 330 ps VOD = 1200 mVp-p
0/F 1
0
-6 dB 330 ps VOD = 1000 mVp-p
-3 dB 330 ps VOD = 1200 mVp-p
0/F 1
1
-9 dB 300 ps VOD = 1000 mVp-p
enhanced
-11 dB 300 ps VOD = 1200 mVp-p
enhanced
0/F 0
F
-6 dB 300 ps VOD = 1000 mVp-p
enhanced
-8 dB 300 ps VOD = 1200 mVp-p
enhanced
0/F 1
F -12 dB 300 ps VOD = 1000 mVp-p
enhanced
-13 dB 300 ps VOD = 1200 mVp-p
enhanced
0/F F
0
-9 dB 250 ps VOD = 1000 + 200 mVp-p
enhanced
-10 dB 250 ps VOD = 1200 + 200 mVp-p
enhanced
Recommended Media Length
10 inch FR4 trace or 1 meter (28 AWG)
20 inch FR4 trace or 2 meters (28 AWG)
15 inch FR4 trace or 2 meters (28 AWG)
25 inch FR4 trace or 3 meters (28 AWG)
20 inch FR4 trace or 2 meters (28 AWG)
5 meters (28 AWG)
7 meters (28 AWG)
5 meters (26 AWG)
7 meters (26 AWG)
8 meters (24 AWG)
9 meters (24 AWG)
8 meters (26 AWG)
9 meters (26 AWG)
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