LM35 (DZ) problem with output

[geobabu]

Hi,
Please help me regarding the problem facing with LM35 (DZ) temperature Sensor interfacing. Normally the LM35 provides an o/p @ 10mV/°C .

I had connected a LM35, V+ to 5V, and with a DMM , Vout pin shows around 2.7V ~ 2.85V, while I am expecting around .26 ~ .29mV @ room temperature. Other thing is when the temperature increases , the voltage is gradually decreasing and vice versa. When I connected a 1K resistor across, Vout & GND, the 2.7V ~ 2.85V range reduced to ~ .54, its decreases as temperature rises.

Also I didn't connect the o/p to any other device like opamp/ADC.

I got the same results with another sensor also. I think, something wrong over here. Please help me to find out the issue.

Thanks in Advance.
Geo

 

[andi21]

maybe its better if you show your schematic..
if you see the datasheet, you will see that you should put resistor between vcc and input..

CMIIW

 

[ravimarcus]

Ensure that you have connected the V+ to 5V and GND to Ground. The datasheet shows the bottom view of the device.

At room temperature of say 25C, you should get 250 mV.

Cheers

Ravi

 

[cameo_2007]

It is quite straight forward and pretty simple.
Have you referred the application circuit in the data sheet clearly ? an i think you are expecting .26V and not .26mV @ room temperature

 

[Pravinspidy]

please connect the vout to the oscilloscope & verify it.......

 

[dheena]

connect a 0.1uF capacitor across the power supply and also across your o/p and gnd teminal....