AD9222 Analog Devices, AD9222 Datasheet - Page 32

• Manufacturer Part Number: AD9222
• Description: Octal, 12-Bit, 40/50/65 MSPS Serial LVDS 1.8 V A/D Converter
• Manufacturer: Analog Devices

Specifications of AD9222

• Resolution (bits): 12bit
• # Chan: 8
• Sample Rate: 65MSPS
• Interface: LVDS,Ser
• Analog Input Type: Diff-Uni
• Ain Range: 2 V p-p
• Adc Architecture: Pipelined
• Pkg Type: CSP

AD9222
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 82 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
Figure 81. V
0.5
1.0
REF
Accuracy vs. Load, AD9222-50
CURRENT LOAD (mA)
1.5
2.0
2.5
3.0
3.5
Rev. F | Page 32 of 60
–0.02
–0.04
–0.06
–0.08
–0.10
–0.12
–0.14
–0.16
–0.18
0.02
0
–40
Figure 82. Typical V
–20
0
TEMPERATURE (°C)
20
REF
Drift, AD9222-50
40
Data Sheet
60
80