AD5415YRU Analog Devices Inc, AD5415YRU Datasheet - Page 24

• Manufacturer Part Number: AD5415YRU
• Description: IC DAC DUAL 12BIT MULT 24-TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD5415YRU

• Settling Time: 120ns
• Number Of Bits: 12
• Data Interface: Serial
• Number Of Converters: 2
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 3.5µW
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP
• For Use With: EVAL-AD5415EBZ - BOARD EVALUATION FOR AD5415
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

AD5415
PCB LAYOUT AND POWER SUPPLY DECOUPLING
In any circuit where accuracy is important, careful considera-
tion of the power supply and ground return layout helps to
ensure the rated performance. The printed circuit board on
which the AD5415 is mounted should be designed so that the
analog and digital sections are separated and confined to
certain areas of the board. If the DAC is in a system where
multiple devices require an AGND-to-DGND connection, the
connection should be made at one point only. The star ground
point should be established as close as possible to the device.
The DAC should have ample supply bypassing of 10 μF in
parallel with 0.1 μF on the supply located as close as possible to
the package, ideally right up against the device. The 0.1 μF
capacitor should have low effective series resistance (ESR) and
low effective series inductance (ESI), like the common ceramic
types of capacitors that provide a low impedance path to ground
at high frequencies, to handle transient currents due to internal
logic switching. Low ESR 1 μF to 10 μF tantalum or electrolytic
capacitors should also be applied at the supplies to minimize
transient disturbance and filter out low frequency ripple.
Components, such as clocks, that produce fast-switching signals
should be shielded with digital ground to avoid radiating noise
to other parts of the board, and they should never be run near
the reference inputs.
Avoid crossover of digital and analog signals. Traces on
opposite sides of the board should run at right angles to each
other. This reduces the effects of feedthrough on the board. A
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microstrip technique is by far the best, but its use is not always
possible with a double-sided board. In this technique, the
component side of the board is dedicated to the ground plane,
and signal traces are placed on the soldered side.
It is good practice to use compact, minimum lead length PCB
layout design. Leads to the input should be as short as possible
to minimize IR drops and stray inductance.
The PCB metal traces between V
matched to minimize gain error. To maximize high frequency
performance, the I-to-V amplifier should be located as close as
possible to the device.
EVALUATION BOARD FOR THE DAC
The evaluation board consists of an AD5415 DAC and a
current-to-voltage amplifier, the AD8065. Included on the
evaluation board is a 10 V reference, the ADR01. An external
reference can also be applied via an SMB input.
The evaluation kit consists of a CD-ROM with self-installing
PC software to control the DAC. The software allows the user to
write a code to the device.
POWER SUPPLIES FOR THE EVALUATION BOARD
The board requires ±12 V and +5 V supplies. The +12 V V
and −12 V V
is used to power the DAC (V
Both supplies are decoupled to their respective ground plane
with 10 μF tantalum and 0.1 μF ceramic capacitors.
SS
are used to power the output amplifier; the +5 V
DD1
) and transceivers (V
REF
and R
FB
should also be
CC
).
DD