How can I choice your SPICE model for ADuC7036 input part?

Hi Kaos,

the models within the SPICE zip-file are predominantly amplifiers.

We do not have any SPICE model for Sigma-Delta ADCs.

I attached an excel sheet which allows you to analyse the ADuC7036 Digital Filter Frequency Response for
different ADCFLT settings, please refer to ADC section in the ADuC7036 datasheet for details on these ADCFLT settings.

regards

Holger

Thanks Holger,

1)

Do you have any analyser or simulator for the parts BUF and PGA?

2)

As for your digital fiter calcurator you enclosed, is this applyied for your part of "precision analog aquisition"?

Thanks Kaos

Hi Kaos,

1) We don't have any analyser or simulator for the buffer and the PGA.

2) the calculator allows you to analyse the frequency response of the digital filter dependant on the filter settings, these filter settings define the data / conversion rate of the ADC.

I am not entirely sure what you mean by: is this applyied for your part of "precision analog aquisition"?

can you please clarify.

regards

Holger

Hi Holger,

I see that your calculator is used for the conversion rate of ADC.

And you dont have any analyser or simulator also.

So when we do out SPICE simulation, how can we put the virtual device for IN/OUT ?

It means the equivalent circuit as C,R,Di,L etc.

We would like to do our SPICE simulator with the equivalent circuit......

Thanks Kaos

Thank you for youe great support, Holger!

We will try to do our SPICE with your great comment.

Thanks again,Kaos

Hi Kaos,

An ADuC7036 analog-to-digital converter measures voltage by
using switching capacitor technology to build up a charge balancing circuit.

The input capacitor, and the internal reference capacitor
are switched at a fixed sampling rate, and their charge is pumped into the
integrator. A comparator checks the integrator output and controls the
phase of the input switches to close the feedback loop, which balances the
charges flowing through the input capacitor and reference paths.

The ADC input switch & capacitor is not really relevant,
because the IADC presents a relatively high impedance input at all times. 

There should not be any significant load on the IADC input.
There is some small dynamic activity (due to internal chopping), but it's small.

(Refer to the Current Channel input spec.)

The VBAT input only sees the attenuator resistor, and can therefore be modelled
easily.

Note: there are ESD diodes on the input pins, however for
normal operation the inputs will stay in the valid operating range,  

therefore the diodes should not have any effect, other than
some leakage current over temperature.

I hope this helps

Regards

Holger