AT90USBKEY2 Atmel, AT90USBKEY2 Datasheet - Page 11

• Manufacturer Part Number: AT90USBKEY2
• Description: KIT DEMO FOR AT90USB
• Manufacturer: Atmel

Specifications of AT90USBKEY2

• Main Purpose: USB Controller
• Embedded: *
• Utilized Ic / Part: AT90USB1286, AT90USB1287, AT90USB646, AT90USB647
• Primary Attributes: *
• Secondary Attributes: *
• Supplier: Atmel
• Architecture: 8/16-bit
• Interfaces: USB
• For Use With: ATSTK525 - KIT STARTER FOR AT90USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AT90USBKEY; AT90USBKEY

AT90USBKey Hardware User Guide
The NTC thermistor used in AT90USBKey has a resistance of 100 KΩ
and a beta-value of 4250 ±3%. By the use of the following equation, the temperature (T)
can be calculated:
The following cross table also can be used. It is based on the above equation.
Table 2-2 . Thermistor Values versus Temperature
Temp.
(°C)
-20
-19
-18
-17
-16
-15
-14
-13
-12
-10
-11
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
Where:
1263,757
1182,881
1107,756
1037,934
973,006
912,596
856,361
803,984
755,175
709,669
667,221
627,604
590,613
556,056
523,757
493,555
465,300
438,854
414,089
390,890
369,145
348,757
329,630
294,826
311,680
(KΩ)
T
R
T
=
R
ß
R
T
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
⎛
0
T
0
ln
= 4250 ±3%
= 298 °K (273 °K + 25°K)
= Thermistor value (Ω) at T temperature (°Kelvin)
= 100 KΩ
R
- - - - - - -
R
T
0
β
Temp.
⎞
⎠
(°C)
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
+
- - - - - -
T
β
0
±
5% at 25°C
212,958
201,989
191,657
181,920
172,740
164,083
155,914
148,205
140,926
134,051
127,555
121,414
104,919
100,000
115,608
110,116
95,342
90,930
86,750
82,787
79,030
75,466
72,085
68,876
65,830
(KΩ)
R
T
Temp.
(°C)
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
50,486
48,350
46,316
44,380
42,537
40,781
39,107
37,513
35,992
34,542
33,159
31,840
30,580
29,378
28,229
27,133
26,085
25,084
24,126
22,336
21,498
20,697
19,930
19,196
23,211
(KΩ)
R
T
Using the AT90USBKey
Temp.
(°C)
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
±
5% at 25°C (T
7627A–AVR–04/06
15,396
14,851
14,329
13,828
13,347
12,885
12,442
12,017
10,838
10,476
10,128
11,608
11,215
9,793
9,471
9,161
8,863
8,576
8,300
8,035
7,779
7,533
7,296
7,067
6,847
(KΩ)
R
T
2-11
0
)