CC2650: Sensor Controller Programmable Current Source characteristics

Simon Falsig

Part Number: CC2650

Hi,

I'm currently looking at using the CC2650 Sensor Controller Programmable Current Source to source 20uA of current to a 10k thermistor, then read the value with the ADC, also using the Sensor Controller. This is currently working quite well, but I was wondering if there is more information available on the characteristics of the programmable current source - especially with regard to its temperature dependence?

According to the Sensor Controller Help files, the current source itself is current dependent, and can actually be used for internal temperature measurement by connecting it to an internal, fixed resistor - but I haven't been able to find anything about how much the current varies with temperature, what the minimum/maximum values are, how the curve looks, and so on. Is this data available somewhere? The CC2650 datasheet only mentions a typical range from 0.25 - 20 uA...

Thanks in advance!

over 6 years ago

0 JXS over 6 years ago

TI__Guru** 105180 points

Hello Simon,

Have you looked at the "Typical Characteristics" section the data sheet? That does have some temp vs current plots.

Best wishes

0 Simon Falsig over 6 years ago in reply to JXS

Intellectual 350 points

Yep, already looked at those - I don't see anything relating to the programmable current source in those plots though?

The only temperature vs current plots I can see are about current consumption in various modes.

0 FredG over 6 years ago in reply to Simon Falsig

TI__Expert 6540 points

Hi Simon, we just released an app note describing this feature, sampling the ISRC over an internal resistor with the 12bit ADC to measure temperature:

Let me know if you have questions

0 Simon Falsig over 6 years ago in reply to FredG

Intellectual 350 points

Hi Fred - thanks! That was more or less exactly what we were looking for.

Bluetooth®︎

Bluetooth forum

CC2650: Sensor Controller Programmable Current Source characteristics