AD7298-1 Analog Devices, AD7298-1 Datasheet - Page 21

• Manufacturer Part Number: AD7298-1
• Description: 8-Channel, 1 MSPS, 10-Bit SAR ADC
• Manufacturer: Analog Devices

Specifications of AD7298-1

• Resolution (bits): 10bit
• # Chan: 8
• Sample Rate: 1MSPS
• Interface: SPI
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref),Uni 1.0V,Uni 1.25,Uni 2.0V,Uni 2.5V
• Adc Architecture: SAR
• Pkg Type: CSP

LAYOUT AND CONFIGURATION
For optimum performance, carefully consider the power supply
and ground return layout on any PCB where the AD7298-1 is
used. The PCB containing the AD7298-1 should have separate
analog and digital sections, each having its own area of the board.
The AD7298-1 should be located in the analog section on any PCB.
Decouple the power supply to the AD7298-1 to ground with
10 µF and 0.1 µF capacitors. Place the capacitors as physically
close as possible to the device, with the 0.1 µF capacitor ideally
right up against the device. It is important that the 0.1 µF
capacitor has low effective series resistance (ESR) and low
effective series inductance (ESL); common ceramic types of
capacitors are suitable. The 0.1 µF capacitors provide a low
impedance path to ground for high frequencies caused by
transient currents due to internal logic switching. The 10 µF
capacitors are the tantalum bead type.
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The power supply line should have as large a trace as possible to
provide a low impedance path and reduce glitch effects on the
supply line. Shield clocks and other components with fast switching
digital signals from other parts of the board by a digital ground.
Avoid crossover of digital and analog signals, if possible. When
traces cross on opposite sides of the board, ensure that they run
at right angles to each other to reduce feedthrough effects on
the board.
The best board layout technique is the microstrip technique where
the component side of the board is dedicated to the ground
plane only, and the signal traces are placed on the solder side;
however, this is not always possible with a 2-layer board.
AD7298-1