GS3590 datasheet(53/118 Pages) SEMTECH

53 / 118 page

GS3590

Final Data Sheet Rev.4



PDS-061414 September 2017

53 of 118

Semtech

Proprietary & Confidential

www.semtech.com

3. Pre-emphasis pulse amplitude has a direct impact on swing amplitude. The third

and final step is to readjust the driver swing until the swing amplitude design

target is met. The fine optimization procedure maybe repeated to ensure that the

PPAOptimal and PPWOptimal settings previously determined still hold with the new

DS setting.



Steps 1 and 2 are illustrated in Figure 4-20: PPA Optimization Flow Chart and Figure

4-21: PPW Optimization Flow Chart below.

Figure 4-20: PPA Optimization Flow Chart

yes

Record Data

Read Data

yes

Start Optimization

Set

PPA = PPA

init

PPW = PPW

init

DS = DS

init

Measure initial Jitter

record results for

measurement# n=0

If (PPA + a) < 50

PPA = PPA + a

n = n + 1

Measure Jitter

record results for

measurement# n

If Jitter(n) <

jitter(n-1)

PPA = PPA

init

PPW = PPW

init

If n > 1

PPA – (2*a) < 0

PPA Optimization

Complete

PPA

optimal = PPA(n-1)

Recorded

Jitter

Measurement

1, 2, 3, …, n

Parameter and Variable Definition

PPA

init: Initial PPA value from equation result.

PPW

init: Initial PPW value from equation result.

init: Measurement sweep Initial Driver Swing Setting = 9.

PPA

optimal: Post measurement sweep Optimal Pre-emphasis Pulse Amplitude setting.

PPW

optimal: Post measurement sweep Optimal Pre-emphasis Pulse Width setting.

a: Measurement sweep PPA increment value.

n: Measurement sweep test number value.

PPA: Current Measurement Pre-emphasis Pulse Amplitude setting.

PPW: Current Measurement Pre-emphasis Pulse Width setting.

DS: Current Measurement Driver Swing Amplitude setting.

Is Jitter(n) <

jitter(n-1)

Measure Jitter

record results for

measurement# n

PPA = PPA - a

n = n + 1

If (PPA – a) > 0

PPA Optimization

Complete

PPA

optimal = PPA(n-1)

PPA Optimization

Complete

PPA

optimal = PPA(n-1)

GS3590 Datasheet(PDF) 53 Page - Semtech Corporation

GS3590 Datasheet(HTML) 53 Page - Semtech Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL