GX3146 Datasheet, PDF (31/46 Pages) Semtech Corporation – Crosspoint Switch with Trace Equalization and Output De-emphasis

The junction temperature at each temperature sensor in terms of the ADC output code
is given by:
T_j = 0.5489 × JNCTN_TEMP_[3:0] – 263 + δ₃
Where δ₃ is the temperature uncertainty. The accuracy of the temperature sensors can
be improved by calibrating the GX3146 at a known junction temperature. Without
calibration, the temperature uncertainty, due to process variations and component
mismatch, can be as high as ±27°C. After calibration, the uncertainty can be reduced to
about ±2°C.
See Using the Monitoring Features of the GX3290 Application Note for more
information.
Table 4-11: Nominal Temperature-to-Code Conversion
T_j (°C)
-40
-38
-36
-34
-32
-30
-28
-26
-24
-22
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
JNCTN_TEMP_
[3:0]
406
410
414
417
421
424
428
432
435
439
443
446
450
454
457
461
465
468
472
475
479
T_j (°C)
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
JNCTN_TEMP_
[3:0]
483
486
490
494
497
501
505
508
512
516
519
523
527
530
534
538
541
545
548
552
556
T_j (°C)
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
JNCTN_TEMP_
[3:0]
559
563
567
570
574
578
581
585
588
592
596
599
603
607
610
614
618
621
625
629
632
T_j (°C)
86
88
90
92
94
96
98
100
102
104
106
108
110
112
114
116
118
120
122
124
126
JNCTN_TEMP_
[3:0]
636
639
643
647
650
654
658
661
665
669
672
676
680
683
687
690
694
698
701
705
709
GX3146 146 x 146 3.5Gb/s Crosspoint
Final Data Sheet Rev. 2
GENDOC-056075 March 2013
www.semtech.com
31 of 46
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