how does ds18b20 work?

[arjunmanoharan]

can some one explain me how the temperature sensor ds18b20 work.I have the code with me but i just want to know the working of it.

How it generates an analog signal ? how it is related to temperature?

I know a bit about the one wire protocol.

thanks in advance

 

[betwixt]

It doesn't generate an analog signal. The report is entirely digital.

I think the earlier versions of the device used two oscillators, one temperature stabilized, the other temperature dependant, the difference in frequencies was used to produce the numeric result. Later versions used an internal bandgap reference, PN junction to sense temperature and an ADC. From the outside they functioned identically.

Brian.

 

[arjunmanoharan]

Thank you Brain for your support.Can u send me any links showing a detailed working of the temperature sensor(ds18b20) as i have to prepare a report on it.

thanks in advance.

1

 

[betwixt]

I can't help with the internal operation, you will have to contact the manufacturer for more information than is on the data sheet.

There is a reference to the 1-Wire interface and it's problems here:
https://www.maximintegrated.com/en/design/techdocs/tutorials/index.mvp/id/1/c/1-Wire® Devices#c1

Brian.

 

[MrCarlos]

Hello arjunmanoharan

You can also ask to Google.com for: Application's Notes for DS18B20

You'll find a world of information.

 

[arjunmanoharan]

I thank everyone for the support.
I have a small doubt is the ds18b20 a thermistor.

Thank u

 

[betwixt]

A thermistor is a resistor which changes value according to it's temperature. You have to use external circuitry to convert the resistance back to a usable number.
The DS18B20 is a thermometer device, it senses temperature and by way of it's 1-Wire interface, returns it in fractions of degrees Celsius. It also contains alarms, memory, a power system and a digital interface.
The two things are completely different in operation and practical application although they can both be used to measure temperature.

Brian.