LTC2497 Settling Time

Hello RadioRun ,

Single-ended input works by referencing a certain input with respect to COM, so technically it is still differential and the switching algorithm still applies.

Regards,

Yugel

So, how does forcing the average differential input current to zero mitigate external settling errors?  Do you have a model that explains this?  

Also, in Figure 9, it shows what appears to be the sample cap, Ceq, with a value of 12uF.  Shouldn't this be the 11pF listed in the electrical characteristics?  

Hello RadioRun ,

Apologies for the late response. The algorithm works by alternating between differential channels, wherein 2 readings are made and the 1st reading is done normally, 2nd with switched channels with respect to ADC inputs. This is similar to chopping and you can refer to this article below.

Chopping on Sigma-Delta ADCs Application Note (AN-609) (analog.com)

The electrical characteristics only shows 11 pF as its typical value. It can vary by a range of values but does not have a maximum nor a minimum guarantee.

Regards,

Yugel