The output you are seeing (4.3V) is already out of spec, since the ADR444 should be within 5mV of 4.096V. Did you include 0.1uF capacitors at the input and output of the ADR444? The datasheet of the ADR444 indicates that these are required…
The output of U4 (the ADR444) is not connected; what is currently drawn to the NC pin (No Connect) should be drawn to VOUT.
[Edited for clarity]
ADR444 is based on ADI XFET technology which includes a trim terminal that allows output voltage adjustment over a ±0.5% range. For more information regarding output voltage adjustment please see applications information located on page 16…
We need reference voltage of 4,096V with the lowest noise.
We try ADR444 + output filter+pA low noise buffer amplifier.
Before we start counting and beating a dead path, you do not have a appnote or reference design with similar problem?
IBIS models are only used for modelling digital pins. Since the ADR444 is a voltage reference with no digital pins we do not provide an IBIS model for this product.
the datasheet for the AD7626/Ad7625 show the buexternal ref bufffering of the external 4V096 ref before being applied to the REF pins - I dont see in the datasheet the current requirements on the external Ref.
What would the effect on performance…
What are the recommended ADC driver, external reference and reference buffer options?
The ADAS3023 datasheet recommends the ADA4841 and AD8031 as ADC driver (to drive auxiliary input pair - AUX±) and reference buffer, respectively. Other choices…
The AD7961 datasheet recommended ADC drivers are the two single-ended op amps ADA4899-1 and AD4897-1 or differential amplifier ADA4932-1. The low-noise,
Yes you are correct.
With REFBUF enabled, the buffers provide the benefit of giving the user high input impedance and allow high impedance external sources to be directly connected to the reference inputs. But when using external references…