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quality Chip NTC Thermistor Nanjing Shiheng Elec CMFX 503F3950 Temperature Sensor for Electronic Applications factory
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quality Chip NTC Thermistor Nanjing Shiheng Elec CMFX 503F3950 Temperature Sensor for Electronic Applications factory
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Specifications
Resistance @ 25℃:
50kΩ
Power(Watts):
100mW
Operating Temperature:
-40℃~+125℃
Tolerance:
±1%
Steady State Current (Max):
130uA
Thermal Time Constant:
3s
B Constant (25℃/85℃):
4010K
B Constant (25℃/50℃):
3950K
B Constant Tolerance:
±1%
Mfr. Part #:
CMFX 503F3950
Package:
0402
Key Attributes
Model Number: CMFX 503F3950
Product Description

NTC Thermistors

Product Overview
This document outlines the specifications for the CMF series Chip NTC Thermistors from Nanjing Shiheng Electronics Technology Co., Ltd. These thermistors are designed for various electronic applications requiring precise temperature sensing and control. Key features include a wide operating temperature range and reliable performance.

Product Attributes

  • Brand: Shiheng
  • Manufacturer: Nanjing Shiheng Electronics Technology Co., Ltd.
  • Origin: China
  • Product Type: Chip NTC Thermistor

Technical Specifications

Shape and Dimensions

Figure 1 & 2: Dimensions and Recommended PCB Pattern

Type L (inch[mm]) W (inch[mm]) T (inch[mm]) a (inch[mm]) A (inch[mm]) B (inch[mm]) C (inch[mm])
[0402] 0.0390.006 [1.00.15] 0.0200.006 [0.50.15] 0.0200.006 [0.50.15] 0.0100.004 [0.250.1] [0.45-0.55] [0.4-0.5] [0.45-0.55]

Product Identification (Part Number)

CMF X 503 F 3950

Electrical Characteristics

Part No Resistance (25) (k) B Constant (25/50) (K) B Constant (25/85) (K) Permissible Operating Current (25) (mA) Dissipation Factor (mW/) Thermal Time Constant (s) Rated Electric Power (25) (mW) Operating Ambient Temperature ()
CMFX503F3950FB 501% 39501% 4010 0.13 1.0 <3 100 -40+125

Part Number Breakdown

  • Category Type: CMF (Chip NTC Thermistor)
  • External Dimensions (LWT): X [0402] 1.000.500.50
  • Nominal Zero-Power Resistance at 25: 503 (50k)
  • Tolerance of Resistance: F (1%)
  • B Constant: 3950 (3950K)
  • Tolerance of B Constant: F (1%)
  • B Constant Calculation Method: B (25 & 50)

Test Conditions

Standard Atmospheric Conditions: Ambient Temperature: 2015; Relative Humidity: 6520%; Air Pressure: 86 kPa~106 kPa.
Alternative Conditions (for disputed results): Ambient Temperature: 252; Relative Humidity: 655%; Air Pressure: 86 kPa~106 kPa.

Inspection Equipment

  • Visual Examination: 20 magnifier
  • Resistance Value Test: Thermistor resistance tester

Electrical Test Items

  • Nominal Zero-Power Resistance at 25 (R25)
  • Nominal B Constant (Calculated using resistance at different temperatures)
  • Thermal Time Constant
  • Dissipation Factor
  • Rated Power
  • Permissible Operating Current

Reliability Test

Item Standard Requirements
Terminal Strength IEC 60068-2-21 No removal or split of the termination or other defects shall occur. No visible damage. |R25/R25| 2%
Flexure Resistance IEC 60068-2-21 No visible damage. |R25/R25| 2%
Vibration IEC 60068-2-80 No visible damage.
Dropping IEC 60068-2-32 No visible damage.
Solderability IEC 60068-2-58 No visible damage. Wetting shall exceed 95% coverage.
Resistance to Soldering Heat IEC 60068-2-58 No visible damage. |R25/R25| 2%; |B/B| 1%
Temperature Cycling IEC 60068-2-14 No visible damage. |R25/R25| 2%; |B/B| 1%
Resistance to Dry Heat IEC 60068-2-2 No visible damage. |R25/R25| 2%; |B/B| 1%
Resistance to Cold IEC 60068-2-1 No visible damage. |R25/R25| 2%; |B/B| 1%
Resistance to Damp Heat IEC 60068-2-78 No visible damage. |R25/R25| 2%; |B/B| 1%
Resistance to High Temperature Load IEC 60539-1 5.25.4 No visible damage. |R25/R25| 2%; |B/B| 1%

Taping

Type Tape Thickness (mm) Tape Material Quantity per Reel
0201 0.50.15 Paper Tape 15K
X 0.50.15 Paper Tape 10K
A 0.80.15 Paper Tape 4K
B 0.850.2 Paper Tape 4K

Storage Conditions

  • Storage Temperature: -1040
  • Relative Humidity: 75%RH
  • Conditions to Avoid: Dust, corrosive atmosphere, direct sunlight.
  • Period of Storage: 6 Months after delivery

Notes & Warnings

  • Do not operate or store under corrosive, deoxidized, volatile, inflammable, dusty, high/low pressure, humid conditions, or in places with brine, oil, chemical liquid, organic solvent, or intense vibration.
  • The ceramic body is fragile; avoid excessive pressure or impact.
  • Do not operate beyond the specified operating temperature range.

Recommended Soldering Technologies

  • Re-flowing Profile: Ramp 1~2/sec. Pre-heating: 150~170/9030 sec. Time above 240: 20~40 sec. Peak temperature: 260Max./10 sec. Solder paste: 96.5Sn/3.0Ag/0.5Cu. Max. 2 times for re-flowing.
  • Iron Soldering Profile: Iron soldering power: Max.20W. Pre-heating: 150/60sec. Soldering Tip temperature: 280Max. Soldering time: 3 sec Max. Solder paste: 96.5Sn/3.0Ag/0.5Cu. Max. 1 time for iron soldering. (Note: Do not apply the tip of the soldering iron to the terminal electrodes.)

R-T Table (CMFXX503F3950FB)

Temp. () R_Min (Kohm) R_Cent (Kohm) R_Max (Kohm) Res TOL. Temp. TOL.()
-40 1,542.135 1,612.772 1,686.477 4.57% 0.67
-39 1,446.393 1,511.666 1,579.727 4.50% 0.66
-38 1,357.159 1,417.493 1,480.362 4.44% 0.66
-37 1,273.956 1,329.741 1,387.831 4.37% 0.65
-36 1,196.343 1,247.937 1,301.626 4.30% 0.65
-35 1,123.913 1,171.644 1,221.280 4.24% 0.64
-34 1,056.293 1,100.462 1,146.364 4.17% 0.64
-33 993.136 1,034.020 1,076.480 4.11% 0.63
-32 934.124 971.977 1,011.264 4.04% 0.63
-31 878.962 914.018 950.377 3.98% 0.62
-30 827.379 859.852 893.510 3.91% 0.62
-29 779.122 809.210 840.375 3.85% 0.61
-28 733.959 761.843 790.708 3.79% 0.61
-27 691.675 717.523 744.262 3.73% 0.60
-26 652.072 676.037 700.812 3.66% 0.59
-25 614.964 637.188 660.149 3.60% 0.59
-24 580.182 600.795 622.079 3.54% 0.58
-23 547.566 566.689 586.422 3.48% 0.58
-22 516.971 534.715 553.013 3.42% 0.57
-21 488.260 504.727 521.698 3.36% 0.57
-20 461.308 476.593 492.335 3.30% 0.56
-19 435.997 450.186 464.791 3.24% 0.55
-18 412.219 425.393 438.945 3.19% 0.55
-17 389.872 402.106 414.683 3.13% 0.54
-16 368.864 380.226 391.899 3.07% 0.54
-15 349.106 359.660 370.495 3.01% 0.53
-14 330.518 340.322 350.381 2.96% 0.52
-13 313.025 322.132 331.472 2.90% 0.52
-12 296.556 305.017 313.689 2.84% 0.51
-11 281.045 288.908 296.960 2.79% 0.50
-10 266.433 273.739 281.217 2.73% 0.50
-9 252.662 259.452 266.397 2.68% 0.49
-8 239.680 245.989 252.439 2.62% 0.48
-7 227.437 233.301 239.291 2.57% 0.48
-6 215.888 221.337 226.901 2.51% 0.47
-5 204.989 210.053 215.220 2.46% 0.46
-4 194.700 199.406 204.206 2.41% 0.46
-3 184.985 189.358 193.816 2.35% 0.45
-2 175.808 179.872 184.011 2.30% 0.44
-1 167.137 170.913 174.757 2.25% 0.43
0 158.941 162.449 166.019 2.20% 0.43
1 151.192 154.451 157.765 2.15% 0.42
2 143.863 146.891 149.967 2.09% 0.41
3 136.929 139.741 142.597 2.04% 0.41
4 130.368 132.979 135.629 1.99% 0.40
5 124.156 126.580 129.039 1.94% 0.39
6 118.274 120.524 122.805 1.89% 0.38
7 112.702 114.791 116.906 1.84% 0.38
8 107.424 109.361 111.323 1.79% 0.37
9 102.420 104.218 106.036 1.74% 0.36
10 97.677 99.343 101.028 1.70% 0.35
11 93.179 94.723 96.284 1.65% 0.34
12 88.912 90.343 91.788 1.60% 0.34
13 84.863 86.189 87.526 1.55% 0.33
14 81.021 82.247 83.484 1.50% 0.32
15 77.372 78.507 79.651 1.46% 0.31
16 73.908 74.957 76.014 1.41% 0.30
17 70.617 71.586 72.562 1.36% 0.30
18 67.490 68.385 69.286 1.32% 0.29
19 64.517 65.344 66.174 1.27% 0.28
20 61.692 62.454 63.219 1.22% 0.27
21 59.005 59.707 60.411 1.18% 0.26
22 56.449 57.095 57.742 1.13% 0.25
23 54.017 54.611 55.206 1.09% 0.25
24 51.703 52.248 52.794 1.04% 0.24
25 49.500 50.000 50.500 1.00% 0.23
26 47.361 47.860 48.360 1.04% 0.24
27 45.325 45.823 46.322 1.09% 0.25
28 43.388 43.883 44.380 1.13% 0.26
29 41.543 42.035 42.529 1.18% 0.27
30 39.786 40.275 40.766 1.22% 0.29
31 38.113 38.597 39.084 1.26% 0.30
32 36.518 36.998 37.481 1.30% 0.31
33 34.999 35.474 35.952 1.35% 0.32
34 33.550 34.020 34.492 1.39% 0.33
35 32.169 32.633 33.100 1.43% 0.35
36 30.851 31.309 31.771 1.47% 0.36
37 29.595 30.046 30.502 1.52% 0.37
38 28.395 28.841 29.290 1.56% 0.38
39 27.251 27.689 28.132 1.60% 0.40
40 26.158 26.590 27.026 1.64% 0.41
41 25.115 25.540 25.969 1.68% 0.42
42 24.119 24.536 24.959 1.72% 0.43
43 23.167 23.577 23.993 1.76% 0.45
44 22.257 22.661 23.069 1.80% 0.46
45 21.388 21.784 22.186 1.84% 0.47
46 20.557 20.946 21.340 1.88% 0.49
47 19.762 20.144 20.532 1.92% 0.50
48 19.002 19.377 19.757 1.96% 0.51
49 18.276 18.643 19.016 2.00% 0.53
50 17.580 17.941 18.307 2.04% 0.54
51 16.914 17.268 17.627 2.08% 0.55
52 16.277 16.624 16.976 2.12% 0.57
53 15.667 16.007 16.352 2.16% 0.58
54 15.083 15.416 15.754 2.20% 0.59
55 14.524 14.850 15.181 2.23% 0.61
56 13.988 14.307 14.632 2.27% 0.62
57 13.474 13.787 14.105 2.31% 0.64
58 12.982 13.288 13.600 2.35% 0.65
59 12.510 12.809 13.115 2.38% 0.66
60 12.057 12.351 12.650 2.42% 0.68
61 11.623 11.911 12.203 2.46% 0.69
62 11.207 11.488 11.775 2.50% 0.71
63 10.808 11.083 11.364 2.53% 0.72
64 10.425 10.694 10.969 2.57% 0.73
65 10.057 10.320 10.589 2.61% 0.75
66 9.704 9.962 10.225 2.64% 0.76
67 9.365 9.617 9.875 2.68% 0.78
68 9.040 9.286 9.538 2.71% 0.79
69 8.727 8.968 9.215 2.75% 0.81
70 8.427 8.663 8.904 2.79% 0.82
71 8.138 8.369 8.605 2.82% 0.84
72 7.861 8.086 8.317 2.86% 0.85
73 7.594 7.815 8.041 2.89% 0.87
74 7.338 7.554 7.775 2.93% 0.88
75 7.092 7.303 7.519 2.96% 0.90
76 6.855 7.061 7.273 3.00% 0.91
77 6.627 6.828 7.035 3.03% 0.93
78 6.408 6.605 6.807 3.07% 0.95
79 6.197 6.389 6.587 3.10% 0.96
80 5.994 6.182 6.376 3.13% 0.98
81 5.798 5.982 6.172 3.17% 0.99
82 5.610 5.790 5.975 3.20% 1.01
83 5.429 5.605 5.786 3.23% 1.02
84 5.254 5.426 5.604 3.27% 1.04
85 5.086 5.254 5.428 3.30% 1.06
86 4.924 5.089 5.258 3.33% 1.07
87 4.768 4.929 5.095 3.37% 1.09
88 4.618 4.775 4.937 3.40% 1.10
89 4.473 4.627 4.785 3.43% 1.12
90 4.333 4.483 4.639 3.47% 1.14
91 4.198 4.345 4.497 3.50% 1.15
92 4.068 4.212 4.361 3.53% 1.17
93 3.943 4.084 4.229 3.56% 1.19
94 3.822 3.960 4.102 3.59% 1.20
95 3.705 3.840 3.979 3.63% 1.22
96 3.593 3.724 3.861 3.66% 1.24
97 3.484 3.613 3.746 3.69% 1.25
98 3.379 3.505 3.636 3.72% 1.27
99 3.278 3.401 3.529 3.75% 1.29
100 3.180 3.301 3.426 3.78% 1.31
101 3.086 3.204 3.326 3.81% 1.32
102 2.994 3.110 3.229 3.84% 1.34
103 2.906 3.019 3.136 3.88% 1.36
104 2.821 2.932 3.046 3.91% 1.38
105 2.739 2.847 2.959 3.94% 1.39
106 2.660 2.765 2.875 3.97% 1.41
107 2.583 2.686 2.794 4.00% 1.43
108 2.509 2.610 2.715 4.03% 1.45
109 2.437 2.536 2.639 4.06% 1.46
110 2.367 2.464 2.565 4.09% 1.48
111 2.300 2.395 2.494 4.12% 1.50
112 2.235 2.328 2.425 4.15% 1.52
113 2.172 2.263 2.358 4.18% 1.54
114 2.112 2.201 2.293 4.20% 1.56
115 2.053 2.140 2.230 4.23% 1.57
116 1.996 2.081 2.170 4.26% 1.59
117 1.941 2.024 2.111 4.29% 1.61
118 1.887 1.969 2.054 4.32% 1.63
119 1.836 1.916 1.999 4.35% 1.65
120 1.786 1.864 1.946 4.38% 1.67
121 1.737 1.814 1.894 4.41% 1.69
122 1.690 1.765 1.844 4.43% 1.70
123 1.645 1.718 1.795 4.46% 1.72
124 1.601 1.673 1.748 4.49% 1.74
125 1.558 1.629 1.702 4.52% 1.76

2410121438_Nanjing-Shiheng-Elec-CMFX-503F3950_C2889042.pdf
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