Atmel AVR1923

13

8394B-AVR-02/12

Temp.

[°C]

NTC

resistance

[kΩ]

Temp.

[°C]

NTC

resistance

[kΩ]

Temp.

[°C]

NTC

resistance

[kΩ]

Temp.

[°C]

NTC

resistance

[kΩ]

-7

528.602

23

109.970

53

29.366

83

9.510

-6

499.212

24

104.852

54

28.203

84

9.185

-5

471.632

25

100.000

55

27.091

85

8.873

-4

445.772

26

95.398

56

26.028

86

8.572

-3

421.480

27

91.032

57

25.013

87

8.283

-2

398.652

28

86.889

58

24.042

88

8.006

-1

377.193

29

82.956

59

23.113

89

7.738

Two common approximations can be used to model the temperature vs. resistance

characteristic; these are the B parameter and the Steinhart-Hart equations.

Coefficients for both formulas can be calculated from Table 5-8.

When the internal reference VCC/1.6 is used and the ADC is measuring in signed

single ended mode the codes in Table 5-9 can be read from the ADC at the various

temperatures. The calculation is based on Table 5-8.

Table 5-9. ADC codes vs. temperature (signed single ended mode with internal

VCC/1.6 reference).

ADC input [V] Temp. [°C]

ADC codes

ADC input [V]

Temp. [°C]

ADC codes

2.076

-14

2047

0.347

38

345

2.030

-13

2014

0.334

39

332

1.983

-12

1968

0.321

40

319

1.936

-11

1921

0.309

41

307

1.889

-10

1875

0.297

42

295

1.841

-9

1828

0.286

43

283

1.794

-8

1781

0.275

44

273

1.747

-7

1734

0.264

45

262

1.700

-6

1687

0.254

46

252

1.653

-5

1640

0.244

47

243

1.606

-4

1594

0.235

48

233

1.560

-3

1548

0.226

49

225

1.514

-2

1503

0.218

50

216

1.469

-1

1458

0.209

51

208

1.425

0

1414

0.202

52

200

1.380

1

1370

0.194

53

193

1.337

2

1327

0.187

54

185

1.294

3

1285

0.180

55

178

1.252

4

1243

0.173

56

172

1.211

5

1202

0.167

57

165

1.171

6

1162

0.161

58

159

1.131

7

1123

0.155

59

154

1.093

8

1084

0.149

60

148