ADC Tracking Time

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

Is there any data available on the tracking time used by the internal ADC? I haven't been able to find that information in the datasheet.

By tracking time I mean the length of time in which the sampling capacitor is connected to a chosen analog input. Knowing this would be very helpful for designing an ADC input circuit.

Also would it be possible to configure the ADC so that the sample capacitor is left connected to the analog input while it is not sampling. This would make it much easier to measure high impedance, slowly changing signals such as a battery voltage.

Thanks

0 Likes
1 Solution
JacobT_81
Employee
Employee
250 replies posted 100 replies posted 50 replies posted

Hi orice170

Per the technical reference doc, with the pin configured as an ADC input, it should have 500k impedance on it.

I'm unclear on what you mean by tracking time. Our sampling rate is configurable. 5-8-187khz. Our Channel switching rate is 133.33 Kch/s.

Jacob

View solution in original post

0 Likes
3 Replies
BoonT_56
Employee
Employee
500 likes received 250 likes received 100 likes received

We have a document "Wiced smart hardware interfaces" in the "Doc" folder within the IDE. Did you have a chance to review it?

0 Likes
Anonymous
Not applicable

I had read that and the datasheet for both the BCM20737 and BCM20737S. They state that the ADC conversion time is 10uS, however I have not been able to find any information on the tracking time. If the information is not available at this time I will attempt to measure it and post my results here.

0 Likes
JacobT_81
Employee
Employee
250 replies posted 100 replies posted 50 replies posted

Hi orice170

Per the technical reference doc, with the pin configured as an ADC input, it should have 500k impedance on it.

I'm unclear on what you mean by tracking time. Our sampling rate is configurable. 5-8-187khz. Our Channel switching rate is 133.33 Kch/s.

Jacob

0 Likes