ST LM135, LM235, LM335 User Manual

LM135-LM235-LM335

Precision temperature sensors

Features

■Directly calibrated in °K

■1°C initial accuracy

■Operates from 450µA to 5mA

■Less than 1Ω dynamic impedance

Description

The LM135, LM235, LM335 are precision temperature sensors which can be easily calibrated. They operate as a 2-terminal Zener and the breakdown voltage is directly proportional to the absolute temperature at 10mV/°K.

The circuit has a dynamic impedance of less than 1Ω and operates within a range of current from 450µA to 5mA without alteration of its characteristics.

Calibrated at +25°C, the LM135, LM235, and LM335 have a typical error of less than 1°C over a 100°C temperature range. Unlike other sensors, the LM135, LM235, LM335 have a linear output.

TO-92

(Plastic package)

SO-8

(Plastic micropackage)

Pin connections

TO-92

(Bottom view)

ADJ v+ v-

SO-8

(Top view)

V+	NC	NC	ADJ
8	7	6	5

	1		2				3		4
	NC			NC			NC		V-

February 2008

Rev 3

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Schematic diagram	LM135-LM235-LM335

1 Schematic diagram

Figure 1. Schematic diagram

2	Absolute maximum ratings
	Table 1.	Absolute maximum ratings (AMR)
	Symbol	Parameter	LM135	LM235	LM335-	Unit
					LM335A
	IR	Current
		Reverse		15		mA
	IF
		Forward		10
		Operating free-air temperature
	Toper	range(1)				°C
		Continuous	-55 to +150	-40 to +125	-40 to +100
		Intermittent	+150 to +200	+125 to +150	+100 to +125
	Tstg	Storage temperature range		-65 to +150		°C

1. Tj ≤ 150°C

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LM135-LM235-LM335								Temperature accuracy
3	Temperature accuracy
Table 2.	Temperature accuracy
			LM135 - LM235 -						LM335
	Parameter			LM335A							Unit
			Min.	Typ.		Max.	Min.		Typ.	Max.
Operating output voltage
Tcase = +25°C, IR = 1mA			2.95	2.98		3.01	2.92		2.98	3.04	V
Uncalibrated temperature error (IR = 1mA)				1		3			4	6	°C
Tcase = +25°C
Tmin ≤ Tcase ≤ Tmax				2		5			5	9
Temperature	error with 25°C calibration
Tmin ≤ Tcase ≤ Tmax., IR = 1mA											°C
LM135 - LM235				0.5		1.5
LM335									1	2
LM335A				0.5		1
Calibrated error at extended temperature
Tcase = Tmax (intermittent)				2					2		°C
Non-linearity (IR = 1mA)				0.3		1					°C
LM135 - LM235									0.3	1.5
LM335				0.3		1.5
LM335A
4	Electrical characteristics
Table 3.	Electrical characteristics
	Parameter		LM135 - LM235				LM335-LM335A				Unit
			Min.	Typ.		Max.	Min.		Typ.	Max.
Operating output voltage change with current
450µA ≤ IR ≤ 5mA at constant temperature				2.5		10			3	14	mV
Dynamic impedance (IR = 1mA)				0.5					0.6		Ω
Output voltage temperature drift				+10					+10		mV/°C
Time constant
Still air				80					80		s
Air 0.5m/s				10					10
Stirred oil				1					1
Time stability (Tcase = +125°C)				0.2					0.2		°C/kh
Note:	Accuracy measurements are made in a well-stirred oil bath. For other conditions, self-
	heating must be considered

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Electrical characteristics			LM135-LM235-LM335
Figure 2. Reverse voltage change		Figure 3.	Calibrated error
Reverse voltage change (mV)		Calibrated error (°C)
	Reverse current (mA)		Temperature (°C)
Figure 4.	Reverse characteristics	Figure 5.	Response time
Reverse current (mA)		Voltage swing (V)
	Reverse voltage (V)		Time (µs)
Figure 6.	Dynamic impedance	Figure 7.	Noise voltage
Dynamic impedance (Ohm)		Noise (nV/√Hz)
	Frequency (Hz)		Frequency (Hz)

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LM135-LM235-LM335	Electrical characteristics
Figure 8. Thermal resistance junction to air	Figure 9. Thermal time constant
Thermal resistance (°C/W)	Time constant (s)
Air velocity (m/s)	Air velocity (m/s)
Figure 10. Thermal response in still air	Figure 11. Thermal response in stirred oil bath
Percent of final value (%)	Percent of final value (%)
Time (min)	Time (s)
Figure 12. Forward characteristics
Forward voltage (V)
Forward current (mA)

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