I have a taken up a task of designing a universal temp monitoring systems which would operate over a wide range of temperature(-200 to 800). I want it to be compatible with different types of sensors like thermocouples, RTD's etc. But for me it is very difficult because i am very weak in analog circuits which is the most essential think for conditioning of sensor signals. So i came to TI for help and here i found the PGA309 which i must say is a fascinating piece of semiconductor. But this device is so full of features that it eventually becomes complex. I have been reading the data sheet for quite some days now, but still don't have a clear view about how to do things. I have many questions to list a few.
1. The data sheet explains PGA309 as an independent system directly controlling an EEPROM without a microcontroller, is that possible?
2. The EEPROM is said to have 17 coefficient values. what are these coefficient values, if i design that system from where will i get those values?
3. Why the Bridge sensor is used with the actual sensing element, can we simply connect the sensor in series with a resistor to form a voltage divider,will that work?
Oh! no i guess i have got it seriously wrong , going through the data sheet of PGA i get a sense that it can only be used in a temperature range of -40C to +125C, is that true.
Muhmmed,
The temperature range of the IC is limited to -40 to 125C; however, this does not mean that your RTD, thermistor, thermocouple, etc. cannot be in an environment such as an oven that exceeds this temperature range.
Matt
Thanks .
But can you please also provide some guidelines on my first question.
Hallo
Please help me people with your valuable feeds, its such i great place for learning and a source of guidance....plz help TI employees and all u xperts out there..
I have been extensively exploring the available resources in order to bring this project to reality, and i have got some great literature which helped to understand the product better. I am using a J type thermocouple, and i want to use the TI TMP275 for its COld Junction Compensation, but i don't have any idea how to stick the IC to the cold junction such that accurately senses the temp of the cold end ( I mean to say the IC will be soldered on the PCB and it is meant to sense the ambient surrounding temperature. How should i interface it with the COld junction.