DS125BR401SQ Datasheet, PDF (13/52 Pages) Texas Instruments – Low-Power 12.5-Gbps 4-Lane Repeater With Input Equalization and Output De-Emphasis

DS125BR401
www.ti.com
SNLS419C – JULY 2012 – REVISED APRIL 2013
Table 2. Equalizer Settings
Level
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
EQA1
EQB1
0
0
0
0
R
R
R
R
Float
Float
Float
Float
1
1
1
1
EQA0
EQB
0
R
Float
1
0
R
Float
1
0
R
Float
1
0
R
Float
1
EQ – 8 bits [7:0]
0000 0000 = 0x00
0000 0001 = 0x01
0000 0010 = 0x02
0000 0011 = 0x03
0000 0111 = 0x07
0001 0101 = 0x15
0000 1011 = 0x0B
0000 1111 = 0x0F
0101 0101 = 0x55
0001 1111 = 0x1F
0010 1111 = 0x2F
0011 1111 = 0x3F
1010 1010 = 0xAA
0111 1111 = 0x7F
1011 1111 = 0xBF
1111 1111 = 0xFF
dB at
1.5 GHz
2.5
3.8
5.0
5.9
7.4
6.9
9.0
10.2
8.5
11.7
13.2
14.4
14.4
16.0
17.6
18.7
dB at
2.5 GHz
3.5
5.4
7.0
8.0
10.3
10.2
12.4
13.8
12.6
16.2
18.3
19.8
20.5
22.2
24.4
25.8
dB at
4 GHz
3.8
6.7
8.4
9.3
12.8
13.9
15.3
16.7
17.5
20.3
22.8
24.2
26.4
27.8
30.2
31.6
dB at
6 GHz
3.1
6.7
8.4
9.1
13.7
16.2
15.9
17.0
20.7
21.8
23.6
24.7
28.0
29.2
30.9
31.9
Suggested Use⁽¹⁾
FR4 < 5 inch trace
FR4 5-10 inch trace
FR4 10 inch trace
FR4 15-20 inch trace
FR4 20-30 inch trace
FR4 25-30 inch trace
FR4 25-30 inch trace
8m, 30awg cable
> 8m cable
(1) Cable and FR4 lengths are for reference only. FR4 lengths based on a 100 Ohm differential stripline with 5-mil traces and 8-mil trace
separation. Optimal EQ setting should be determined via simulation and prototype verification.
Table 3. Output Voltage and De-emphasis Settings
Level
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
DEMA1
DEMB1
0
0
0
0
R
R
R
R
Float
Float
Float
Float
1
1
1
1
DEMA0
DEMB0
0
R
Float
1
0
R
Float
1
0
R
Float
1
0
R
Float
1
VOD Vp-p
0.8
0.9
0.9
1.0
1.0
1.0
1.1
1.1
1.1
1.2
1.2
1.2
1.3
1.3
1.3
1.3
DEM dB⁽¹⁾
0
0
- 3.5
0
- 3.5
-6
0
- 3.5
-6
0
- 3.5
-6
0
- 3.5
-6
-9
Inner Amplitude
Vp-p
0.8
0.9
0.6
1.0
0.7
0.5
1.1
0.7
0.6
1.2
0.8
0.6
1.3
0.9
0.7
0.5
Suggested Use⁽²⁾
FR4 <5 inch trace
FR4 <5 inch trace
FR4 10 inch trace
FR4 <5 inch trace
FR4 10 inch trace
FR4 15 inch trace
FR4 <5 inch trace
FR4 10 inch trace
FR4 15 inch trace
FR4 <5 inch trace
FR4 10 inch trace
FR4 15 inch trace
FR4 <5 inch trace
FR4 10 inch trace
FR4 15 inch trace
FR4 20 inch trace
(1) The VOD output amplitude and DEM de-emphasis levels are set with the DEMA/B[1:0] pins.
The de-emphasis levels are also available in PCIe GEN-3 mode when MODE = 1 (tied to VDD).
(2) FR4 lengths are for reference only. FR4 lengths based on a 100 Ohm differential stripline with 5-mil traces and 8-mil trace separation.
Optimal DEM settings should be determined via simulation and prototype verification.
Copyright © 2012–2013, Texas Instruments Incorporated
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