kad2710l Kenet Inc., kad2710l Datasheet - Page 14

• Manufacturer Part Number: kad2710l
• Description: 10-bit, 275msps Analog-to-digital Converter
• Manufacturer: Kenet Inc.

KAD2710L 10-Bit, 275MSPS Analog-to-Digital Converter
Equivalent Circuits
Rev 1.1
DATA
DATA
2mA or
2mA or
3mA
3mA
Figure 23. Analog Inputs
Figure 25. LVDS Outputs
Figure 24. Clock Inputs
OVDD
DATA
DATA
OVDD
OVDD
D[9:0]P
D[9:0]N
Layout Considerations
Split Ground and Power Planes
Data converters operating at high sampling frequen-
cies require extra care in PC board layout. Many
complex board designs benefit from isolating the
analog and digital sections. Analog supply and
ground planes should be laid out under signal and
clock inputs. Locate the digital planes under outputs
and logic pins. Grounds should be joined under the
chip.
Clock Input Considerations
Use matched transmission lines to the inputs for the
analog input and clock signals. Locate transformers,
drivers and terminations as close to the chip as possi-
ble.
Bypass and Filtering
Bulk capacitors should have low equivalent series re-
sistance. Tantalum is a good choice. For best per-
formance, keep ceramic bypass capacitors very
close to device pins. Longer traces will increase in-
ductance, resulting in diminished dynamic perform-
ance and accuracy. Make sure that connections to
ground are direct and low impedance. Avoid form-
ing ground loops.
LVDS Outputs
Output traces and connections must be designed for
50Ω (100Ω differential) characteristic impedance.
Keep traces direct, and minimize bends where possi-
ble. Avoid crossing ground and power plane breaks
with signal traces.
Unused Inputs
Three of the four standard logic inputs (RESET, CLKDIV,
2SC) which will not be operated do not require con-
nection for best ADC performance. These inputs can
be left open if they are not used. VREFSEL must be
held low for internal reference, but can be left open
for external reference.
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