8.2.1.3 Application Curves

The DS320PR810 is a linear redriver that can be used to extend channel reach of a PCIe link. Normally,

PCIe-compliant Tx and Rx are equipped with signal-conditioning functions and can handle channel losses of up

to 36 dB at 16 GHz. With the DS320PR810, the total channel loss between a PCIe root complex and an end

point can be extended up to 58 dB at 16 GHz.

To demonstrate the reach extension capability of the DS320PR810, two comparative setups are constructed. In

first setup as shown in Figure 8-5 there is no redriver in the PCIe 5.0 link. Figure 8-6 shows eye diagram at the

end of the link using SigTest. In second setup as shown in Figure 8-7, the DS320PR810 is inserted in the middle

to extend link reach. Figure 8-8 shows SigTest eye diagram.

Tek 33 GHz

Scope

10 M Math1

capture ->

SigTest

Phoenix 5.0

Keysight

M8040

BERT

PCIe 5.0

Comp pa ern

P9 800 mV

PCIe 5.0

Loss Board

PCIe 5.0

Baseboard

(CBB)

PCIe 5.0

Load Board

(CLB)

PCIe 5.0

Loss Board

Figure 8-5. PCIe 5.0 Link Baseline Setup Without

Redriver the Link Elements

Figure 8-6. PCIe 5.0 link Baseline Setup Without

Redriver Eye Diagram Using SigTest

Tek 33 GHz

Scope

10 M Math1

capture ->

SigTest

Phoenix 5.0

Keysight

M8040

BERT

PCIe 5.0

Comp pa ern

P9 800 mV

PCIe 5.0

Loss Board

PCIe 5.0

Baseboard

(CBB)

PCIe 5.0

Load Board

(CLB)

PCIe 5.0

Loss Board

DS320PR810

Riser card

EQ=10, GAIN=L1

Figure 8-7. PCIe 5.0 Link Setup with the

DS320PR810 the Link Elements

Figure 8-8. PCIe 5.0 Link Setup with the

DS320PR810 Eye Diagram Using SigTest

Table 8-1 summarizes the PCIe 5.0 links without and with the DS320PR810. The illustration shows that redriver

is capable of

≅22 dB reach extension at PCIe 5.0 speed with EQ = 10 (EQ gain of 16 dB) and GAIN1,2 = L1 (flat

gain of −4 dB). Note: actual reach extension depends on various signal integrity factors. It is recommended to

run signal intergrity simulations with all the components in the link to get any guidance.

Table 8-1. PCIe 5.0 Reach Extension using the DS320PR810

Setup

Pre Channel Loss

Post Channel Loss

Total Loss

Eye at BER 1E-12

SigTest Pass?

Baseline – no DUT

—

—

≅36 dB

14 ps, 41 mV

Pass

With DUT (DS320PR810)

≅29 dB

≅29 dB

≅58 dB

14 ps, 33 mV

Pass

www.ti.com

DS320PR810

SNLS668 – AUGUST 2022

Copyright © 2022 Texas Instruments Incorporated

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