1 Features

1? Calibrated Directly in Degrees Fahrenheit

? Linear 10.0 mV/°F Scale Factor

? 1.0°F Accuracy Assured (at 77°F)

? Rated for Full ?50° to 300°F Range

? Suitable for Remote Applications

? Low Cost Due to Wafer-Level Trimming

? Operates From 5 to 30 Volts

? Less Than 90-μA Current Drain

? Low Self-Heating, 0.18°F in Still Air

? Nonlinearity Only ±0.5°F Typical

? Low-Impedance Output, 0.4 Ω for 1-mA Load

2 Applications

? Power Supplies

? Battery Management

?HVAC

? Appliances

3 Description

The LM34 series devices are precision integrated-

circuit temperature sensors, whose output voltage is linearly proportional to the Fahrenheit temperature.

The LM34 device has an advantage over linear

temperature sensors calibrated in degrees Kelvin,

because the user is not required to subtract a large constant voltage from its output to obtain convenient

Fahrenheit scaling. The LM34 device does not

require any external calibration or trimming to provide

typical accuracies of ±1/2°F at room temperature and

±1-1?2°F over a full ?50°F to 300°F temperature range. Lower cost is assured by trimming and

calibration at the wafer level. The low output

impedance, linear output, and precise inherent

calibration of the LM34 device makes interfacing to

readout or control circuitry especially easy. It can be used with single power supplies or with plus and

minus supplies. Because the LM34 device draws only

75 μA from its supply, the device has very low self?

heating, less than 0.2°F in still air.

The LM34 device is rated to operate over a ?50°F to

300°F temperature range, while the LM34C is rated

for a ?40°F to 230°F range (0°F with improved

accuracy). The LM34 devices are series is available

packaged in hermetic TO-46 transistor packages;

while the LM34C, LM34CA, and LM34D are available

in the plastic TO-92 transistor package. The LM34D

device is available in an 8-lead, surface-mount, smalloutline

package. The LM34 device is a complement

to the LM35 device (Centigrade) temperature sensor.