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LM35: Narrower range of Nonlinearity

user6262012
Prodigy 60 points
Part Number: LM35
Other Parts Discussed in Thread: LMT70, , TMP117

Hi,

I need to compare the exact uncertainty of LM35 and LMT70.

From the datasheet, We already know the Nonlinearity of LM35CA is ±0.15℃, but this is the case just in -40℃ to +125℃. 

Tell me the Nonlinearity in narrower range like -20℃ to 60℃.

Moreover, I want to check this "the output-voltage-versus-temperture curve" that defines Non-linearity.

↑　is the note in LM35 datasheet.

If you have V-T table of LM35 like LMT70 have, it will help me. 

Please show me that.  

Best Regards, 

  • +1
    TI__Genius 10070 points

    Hello,

    Thank you for posting to the Sensing forum.

    The nonlinearity of the LM35CA was characterized across the entire specified temperature range, but due to the age of the part I am not able to find additional data for a narrower temperature range. 

    Additionally, there is no LUT we can provide for this part that is similar to the one found in the LMT70 datasheet.

    Best regards,

    Nicole

  • 0 in reply to Nicole Khoury
    TI__Guru* 91166 points

    Dear Sasajima -

    to add to Nicole's reply, the transfer function (equation) is given in the datasheet. Using the device at negative temperatures, will require you to use a load resistor and two diodes to ground (as shown in Figure 18 on page 16 of the datasheet)

    Vout = 10mV/°C x Temp, which can be rewritten to Vout/10mV/°C = Temp and put into Excel to produce: 

    TEMP Vout

    Gain

    (step size)
    -55 -550.00E-3 10.0E-3
    -50 -500.00E-3 10.0E-3
    -45 -450.00E-3 10.0E-3
    -40 -400.00E-3 10.0E-3
    -35 -350.00E-3 10.0E-3
    -30 -300.00E-3 10.0E-3
    -25 -250.00E-3 10.0E-3
    -20 -200.00E-3 10.0E-3
    -15 -150.00E-3 10.0E-3
    -10 -100.00E-3 10.0E-3
    -5 -50.00E-3 10.0E-3
    0 000.00E+0 10.0E-3
    5 50.00E-3 10.0E-3
    10 100.00E-3 10.0E-3
    15 150.00E-3 10.0E-3
    20 200.00E-3 10.0E-3
    25 250.00E-3 10.0E-3
    30 300.00E-3 10.0E-3
    35 350.00E-3 10.0E-3
    40 400.00E-3 10.0E-3
    45 450.00E-3 10.0E-3
    50 500.00E-3 10.0E-3
    55 550.00E-3 10.0E-3
    60 600.00E-3 10.0E-3
    65 650.00E-3 10.0E-3
    70 700.00E-3 10.0E-3
    75 750.00E-3 10.0E-3
    80 800.00E-3 10.0E-3
    85 850.00E-3 10.0E-3
    90 900.00E-3 10.0E-3
    95 950.00E-3 10.0E-3
    100 1.00E+0 10.0E-3
    105 1.05E+0 10.0E-3
    110 1.10E+0 10.0E-3
    115 1.15E+0 10.0E-3
    120 1.20E+0 10.0E-3
    125 1.25E+0 10.0E-3
    130 1.30E+0 10.0E-3
    135 1.35E+0 10.0E-3
    140 1.40E+0 10.0E-3
    145 1.45E+0 10.0E-3
    150 1.50E+0 10.0E-3
  • 0 in reply to Nicole Khoury
    Prodigy 60 points

    Thank you for replying ;)

    I' m sad but will think about to use LMT70 or TMP117.

    Regards,

    sasajima