AD5024 Analog Devices, AD5024 Datasheet - Page 24

• Manufacturer Part Number: AD5024
• Manufacturer: Analog Devices

Specifications of AD5024

• Resolution (bits): 12bit
• Dac Update Rate: 125kSPS
• Dac Settling Time: 8µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

AD5024/AD5044/AD5064
POWER SUPPLY BYPASSING AND GROUNDING
When accuracy is important in a circuit, it is helpful to carefully
consider the power supply and ground return layout on the board.
The printed circuit board (PCB) containing the AD5024/AD5044/
AD5064/AD5064-1 should have separate analog and digital
sections. If the AD5024/AD5044/AD5064/AD5064-1 are in a
system where other devices require an AGND-to-DGND
connection, the connection should be made at one point only.
This ground point should be as close as possible to the
AD5024/AD5044/AD5064/AD5064-1.
The power supply to the AD5024/AD5044/AD5064/AD5064-1
should be bypassed with 10 μF and 0.1 μF capacitors. The capaci-
tors should be as physically close as possible to the device, with
the 0.1 μF capacitor ideally right up against the device. The 10 μF
capacitors are the tantalum bead type. It is important that the
0.1 μF capacitor have low effective series resistance (ESR) and
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low effective series inductance (ESI), such as is typical of common
ceramic types of capacitors. This 0.1 μF capacitor provides a low
impedance path to ground for high frequencies caused by
transient currents due to internal logic switching.
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. Clocks and other fast switching digital signals should
be shielded from other parts of the board by 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 through the
board. The best board layout technique is the microstrip tech-
nique, 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.