AD9219BCPZRL-65 Analog Devices, Inc., AD9219BCPZRL-65 Datasheet - Page 28

• Manufacturer Part Number: AD9219BCPZRL-65
• Description: Quad, 10-bit, 40/65 Msps Serial Lvds 1.8 V A/d Converter
• Manufacturer: Analog Devices, Inc.

AD9219
External Reference Operation
The use of an external reference may be necessary to enhance
the gain accuracy of the ADC or improve thermal drift charac-
teristics. Figure 67 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 of 1.0 V.
–10
–15
–20
–25
–30
–5
5
0
0
0.5
Figure 66. V
1.0
CURRENT LOAD (mA)
REF
1.5
Accuracy vs. Load
2.0
2.5
3.0
3.5
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–0.05
–0.10
–0.15
–0.20
0.20
0.15
0.10
0.05
0
–40
–20
Figure 67. Typical V
0
TEMPERATURE (°C)
20
REF
Drift
40
60
80