Datasheet

AD9212 Data Sheet
Rev. E | Page 30 of 56
External Reference Operation
The use of an external reference may be necessary to enhance
the gain accuracy of the ADC or to improve thermal drift charac-
teristics. Figure 66 shows the typical drift characteristics of the
internal reference in 1 V mode.
When the SENSE pin is tied to AVDD, the internal reference is
disabled, allowing the use of an external reference. The external
reference is loaded with an equivalent 6 kΩ load. An internal
reference buffer generates the positive and negative full-scale
references, REFT and REFB, for the ADC core. Therefore, the
external reference must be limited to a nominal voltage of 1.0 V.
0.02
–0.18
–0.14
–0.10
–0.06
–0.02
–0.16
–0.12
–0.08
–0.04
0
–40
VREF ERROR (%)
TEMPERATURE (°C)
05968-088
–200 20406080
Figure 66. Typical VREF Drift