DS50PCI402_15 Datasheet, PDF (7/38 Pages) Texas Instruments – DS50PCI402 2.5 Gbps / 5.0 Gbps 4 Lane PCI Express Repeater with Equalization and De-Emphasis

DS50PCI402
www.ti.com
SNLS320H – APRIL 2010 – REVISED MARCH 2013
Table 3. Equalization Settings with GST=2 for Pins or SMBus Registers (continued)
EQ1⁽ EQ0^{( EQ Setting}
1)
1) GST[1 BST[2:
:0]
0]
10
110
0
1
10
111
EQ Gain (dB)
1.25 GHz
2.5 GHz
12.3
18.6
12.8
19.8
Suggested Use
50" FR4 (6-mil trace) or 10m (24 AWG) PCIe cable
Table 4. Equalization Settings with GST=3 for Pins or SMBus Registers
EQ1⁽ EQ0^{( EQ Setting}
1)
1) GST[1 BST[2:
:0]
0]
11
000
1
0
11
001
11
010
0
F
11
011
11
100
1
F
11
101
11
110
11
111
EQ Gain (dB)
1.25 GHz
2.5 GHz
6.4
12.2
8.5
15.6
10.4
18.3
12.4
21.3
15.2
25.0
18.1
27.2
19.6
28.8
20.2
30.7
Suggested Use
30" FR4 (6-mil trace) or 7m (24 AWG) PCIe cable
15m (24 AWG) PCIe cable
> 15m (24 AWG) PCIe cable
(1) F=Float (don't drive pin, each float pin has an internal 50K Ohm resistor to VDD and GND), 1=High, 0=Low
The De-Emphasis level must be set when in SMBus mode. See SMBus TRANSACTIONS section and
Table 10 for specific De-Emphasis values.
RATE
0/F
0/F
0/F
0/F
0/F
0/F
0/F
0/F
0/F
1/F
1/F
1/F
1/F
1/F
1/F
1/F
1/F
1/F
Table 5. De-Emphasis Input Select Pins for A and B ports (3–Level Input)
DEM1 DEM0⁽¹
Typical De-
(1)
)
Emphasis Level
Typical DE Pulse
Width
Typical VOD
Suggested Use
0
0
0dB
0ps
1000mV
0
1
-3.5dB
400ps
1000mV
8 inches FR4 (6-mil trace) or less than 1
meter (28 AWG) PCIe cable
1
0
-6dB
400ps
1000mV
1
1
-6dB
400ps enhanced
1000mV
15 inches FR4 (6-mil trace)
0
F
-9dB
400ps enhanced
1000mV
1
F
-12dB
400ps enhanced
1000mV
F
0
-9dB
400ps enhanced
1200mV
30 inches FR4 (6-mil trace)
F
1
-12dB
400ps enhanced
1400mV
40 inches FR4 (6-mil trace)
F
F
Reserved, don't
use
0
0
0dB
0ps
1000mV
0
1
-3.5dB
200ps
1000mV
1
0
-6dB
200ps
1000mV
1
1
-6dB
200ps enhanced
1000mV
10 inches FR4 (6-mil trace)
0
F
-9dB
200ps enhanced
1000mV
1
F
-12dB
200ps enhanced
1000mV
F
0
-9dB
200ps enhanced
1200mV
20 inches FR4 (6-mil trace)
F
1
-12dB
200ps enhanced
1400mV
30 inches FR4 (6-mil trace)
F
F
Reserved, don't
use
(1) F=Float (don't drive pin - (each float pin has an internal 50K Ohm resistor to VDD and GND). Enhanced DE Pulse width provides
additional de-emphasis on second bit. VOD = Voltage Output Differential amplitude. When RATE is floated (F=Auto Rate Detection
Active) DE Level and Pulse Width settings follow detected RATE. RATE=0 is 2.5GBps, RATE=1 is 5 GBps
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