Temperature Sensor

The LM35 series are precision integrated-circuit temperature sensors, with an output voltage linearly proportional to the Centigrade temperature. Thus the LM35 has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large constant voltage from the output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±¼°C at room temperature and ±¾°C over a full −55°C to  +150°C temperature range. Low cost is assured by trimming and calibration at the wafer level. The low output impedance, linear output, and precise inherent calibration of the LM35 make interfacing to readout or control circuitry especially easy. The device is used with single power supplies, or with plus and minus supplies. As the LM35 draws only 60 μA from the supply, it has very low self-heating of less than 0.1°C in still air. The LM35 is rated to operate over a −55°C to +150°C temperature range, while the LM35C is rated for a −40°C to +110°C range (−10° with improved accuracy). The LM35 series is available packaged in hermetic TO transistor packages, while the LM35C, LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The LM35D is also available in an 8-lead surface-mount small outline package and a plastic TO-220 package.

  • Accuracy
    • @ 25 °C ±0.2
    • @ -10 °C ±0.3
    • @ TMAX ±0.4
    • @ TMIN ±0.4
  • Nonlinearity: @ TMIN ≤TA≥TMAX; ±0.18
  • Sensor Gain: @ TMIN ≤TA≥TMAX; ±0.18
  • Load Regulation
    • @ 25 °C; ± 0.4
    • @ TMIN ≤TA≥TMAX; ±0.18
  • Line regulation:
    • @ TA = 25°C; ±0.01
    • 4V ≤Ts≥ 30 V; ±0.02
  • Supply Voltage:  -0.2V(min), 35V(max)
  • Output Voltage: -1V(min), 6V(max)
  • Output Current: 10 mA (max)
  • Electrostatic discharge (ESD) susceptibility  2500 V
  • Storage Temperature: -60 to 180 °C
  • (1) Unless otherwise noted, these specifications apply: −55°C ≤ TJ≤ 150°C for the LM35 and LM35A; −40°C ≤ TJ≤ 110°C for the LM35Cand LM35CA; and 0°C ≤ TJ≤ 100°C for the LM35D. VS= 5 Vdc and ILOAD= 50 μA, in the circuit of Figure 2. These specifications also apply from +2°C to TMAX in the circuit of Figure 1. Specifications in boldface apply over the full rated temperature range.
  • (2) Specifications in boldface apply over the full rated temperature range.
  • (3) Tested Limits are ensured and 100% tested in production.
  • (4) Design Limits are ensured (but not 100% production tested) over the indicated temperature and supply voltage ranges. These limits are not used to calculate outgoing quality levels.
  • (5) Accuracy is defined as the error between the output voltage and 10 mv/°C times the case temperature of the device, at specified conditions of voltage, current, and temperature (expressed in °C).
  • (6) Nonlinearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line, over the rated temperature range of the device.
  • (7) Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output due to heating effects can be computed by multiplying the internal dissipation by the thermal resistance