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AD9371-Chip Questions (ADC, DAC & NCO)

Question asked by NBaheti on Oct 20, 2016
Latest reply on Oct 21, 2016 by sripad


Could you please provide more insights into the following points: 


(a) Is it possible to switch off the input mixer in order to the input signal has direct access to the LPF?
[NB] : From UG-992 there is no strict information if the mixers are at all bypassable. Kindly correct me if wrong. I understand this is also governed by the preceding TIA LPF as well.  In case, if its bypassable, what is recommended for LO-termination?

(b) How high is the ENOB at an input signal with a frequency of 1.7 GHz?  And for 100 MHz? 

[NB] : The ADCs follow highly oversampled sigma-delta architecture, can we actually evaluate ENOB of the ADC by bypassing the digital path or its tricky due to valid JESD204B link configurations? 

(c) How long does it take to change the NCO frequency?

(d) What is the latency time for NCO change the frequency after the setup?

[NB]: It would be good to see if we have some results on this.

(e) Could you describe the LPF before the ADC, as: number of poles, selection of cutoff frequency and type of filter.

[NB] : RX LPF is a TIA with single, real pole frequency response. 3dB BW between 20MHz-100MHz & profile dependent as set in the device structure of AD9371. Refer Fig. 70, 80 in UG-992


(a) How long does it take to change NCO? What is the latency time for NCO change the frequency after the setup?

[NB] : AD9371 

(b) Do you know a DAC only chip with an equivalent block diagram of AD9371's upconverter?

[NB] Better to discuss on email.