LM235D STMicroelectronics, LM235D Datasheet - Page 6

• Manufacturer Part Number: LM235D
• Description: IC TEMPERATURE SENSOR PREC 8SOIC
• Manufacturer: STMicroelectronics

Specifications of LM235D

• Sensing Temperature: -40°C ~ 125°C
• Output Type: Voltage
• Accuracy: ±0.5°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Full Temp Accuracy: 1.5 C
• Supply Voltage (max): 3 V
• Supply Voltage (min): 3 V
• Gain: 10 mV / K
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 1 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application information
5
Typical applications
6/16
Figure 13. Basic temperature sensor
Application information
There is an easy method of calibrating the device for higher accuracies (see
applications).
The single point calibration works because the output of the LM135, LM235, LM335 is
proportional to the absolute temperature with the extrapolated output of sensor going to 0V
at 0°K (-273.15°C). Errors in output voltage versus temperature are only slope. Thus a
calibration of the slope at one temperature corrects errors at all temperatures.
The circuit output (calibrated or not) is given by the equation:
where T is the unknown temperature and To is the reference temperature (in °K).
Nominally, the output is calibrated at 10mV/°K.
Precautions should be taken to ensure good sensing accuracy. As in the case of all
temperatures sensors, self-heating can decrease accuracy. The LM135, LM235, and LM335
should operate with a low current but sufficient to drive the sensor and its calibration circuit
to their maximum operating temperature.
If the sensor is used in surroundings where the thermal resistance is constant, the errors
due to self-heating can be externally calibrated. This is possible if the circuit is biased with a
temperature stable current. Heating will then be proportional to Zener voltage and therefore
temperature. In this way, the error due to self-heating is proportional to the absolute
temperature as scale factor errors.
V
OT
+ VO
TO
x
------ -
To
T
Figure 14. Wide operating supply
LM135-LM235-LM335
Typical