Good NTC ADCs?

Tim Baker

Other Parts Discussed in Thread: ADS1118, ADS1018, TMP411, TMP421, ADS1247, ADS1246, ADS1248

Dear TI,

We did find a lot of fine integrated sensors TI offer, but most of them are SMD.

In case we need to probe a particular point (analogously similar to battery temperature sensing, which could lie at a distance and "remote" to the PCB board), we would like to get a solution by using cheap NTCs.

For within 0-70 degree, and an expected accuracy of ±2, can we use a NTC and then an ADC to convert it to a digital output, then in turned processed by a processor, with a look-up table and so on?

In such a configuration, the NTC is located remotely at the site to get best accuracy, and its leads (wire) connects to board and converted by ADC.

Does TI have any solution like this? May I get some recommendation?

Tim

over 8 years ago

0 Guang Zhou over 8 years ago

TI__Mastermind 27380 points

Hi Tim,

Please check out TI’s ADS1118, which was designed with built in precision cold junction compensation. It may be a perfect fit for your application. And be sure to check out the application section regarding thermal couple measurement.

Regard, Guang

Apps-Sensing Products

0 Tim Baker over 8 years ago in reply to Guang Zhou

Intellectual 540 points

Thanks. We did have look at the thermal couple section and it appears a nice fit. But the ADS1118 is a bit pricey, and we might not need the four input channels. Do we have any ADC also designed for thermal couple application, with a lower price?

0 Guang Zhou over 8 years ago in reply to Tim Baker

TI__Mastermind 27380 points

Tim,

ADS1018 is a 12-bit version, and the price is about half. Other than that I’m not really aware of any other similar products. If you want I can ask the moderator of this forum to move the thread to the precision data converter forum to see if you can get better support there.

You can also check out our remote temperature sensors, such as TMP411, TMP421. These temp sensors don’t use thermal couples, rather a sensing diode (discrete NPN or PNP in diode connection) is placed in contact with the object under measurement. And these temp sensors are very affordable.

Regard, Guang

Apps-Sensing Products

0 Tim Baker over 8 years ago in reply to Guang Zhou

Intellectual 540 points

There are a lot of material on using ads1118 with thermalcouple.

Is there any small size thermalcouple comparable to NTC? And we looked in datasheet and application notes but there are little text on how to set it with NTC thermistor. Would it be more difficult to work with thermistor than with thermalcouple?