DAC70004IPWR datasheet(29/44 Pages) TI2

29 / 44 page

DAC80004, DAC70004, DAC60004

www.ti.com

SLASED6D – APRIL 2016 – REVISED DECEMBER 2017

Product Folder Links: DAC80004 DAC70004 DAC60004

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11 Layout

11.1 Layout Guidelines

A precision analog component requires careful layout, adequate bypassing, and clean, well-regulated power

supplies. As a general rule it is important to keep digital traces as far away from analog traces when possible.

The DACx0004 is often used in close proximity with digital logic, microcontrollers, microprocessors, and digital

signal processors. The more digital logic present in the design and the higher the switching speed, the more

difficult it is to keep digital noise from appearing at the output.

Due to the single ground pin of the DACx0004, all return currents, including digital and analog return currents for

the DAC, must flow through a single point. Ideally, GND must be connected directly to an analog ground plane.

This plane must be separate from the ground connection for the digital components until they were connected at

the power-entry point of the system.

As with the GND connection, VDD should be connected to a 5 V power-supply plane or trace that is separate

from the connection for digital logic until they are connected at the power-entry point. It is recommended to have

an additional 1 μF to 10 μF capacitor and 0.1 μF bypass capacitor. In some situations, additional bypassing may

be required, such as a 100 μF electrolytic capacitor or even a Pi filter made up of inductors and capacitors—all

designed to essentially low-pass filter the 5 V supply, removing the high-frequency noise. In general it is always a

good idea to maintain the digital signals away from analog signals.

11.2 Layout Example

Figure 60. Layout Diagram

DAC70004IPWR Datasheet(PDF) 29 Page - Texas Instruments