AD9481 Analog Devices, AD9481 Datasheet - Page 22

• Manufacturer Part Number: AD9481
• Description: 8-Bit, 250 MSPS, 3.3 V A/D Converter
• Manufacturer: Analog Devices

Specifications of AD9481

• Resolution (bits): 8bit
• # Chan: 1
• Sample Rate: 250MSPS
• Interface: Par
• Analog Input Type: Diff-Uni
• Ain Range: (Vref) p-p,1 V p-p
• Adc Architecture: Pipelined
• Pkg Type: QFP

AD9481
OPTIONAL XTAL
The PCB has been designed to accommodate an optional
crystal oscillator that can serve as a convenient clock source.
The footprint can accept both through-hole and surface-mount
devices, including Vectron XO-400 and Vectron VCC6 family
oscillators.
VCC
OUT–
Figure 38. XTAL Footprint
VCC
OUT+
GND
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To use either crystal, populate C38 and C40 with 0.1 µF capaci-
tors. Populate R48 and R49 with 0 Ω resistors. Place R50, R51,
R59, and R60 with 1 kΩ resistors. Remove C6 and C5. If the
Vectron VCC6 family crystal is being used, populate R57 with a
10 Ω resistor. If using the XO-400 crystal, place jumper E21 or
E22 to E23.
VOLTAGE REFERENCE
The AD9481 has an internal 1 V reference mode. The ADC uses
the internal 1 V reference as the default when sense is set to
ground. An optional on-board external 1.0 V reference
(ADR510) can be used by setting the sense jumper to AVDD, by
placing a jumper on E5 to E3, and by placing a 0 Ω resistor on
R55. When using an external programmable reference, (R20,
R30) remove the sense jumper.
DATA OUTPUTS
The ADC outputs are buffered on the PCB by LVT574 latches
on the data outputs. The latch outputs have series terminating
resistors at the output pins to minimize reflections.