Datasheet

Table Of Contents

DAC5578

DAC6578

DAC7578

www.ti.com

SBAS496A –MARCH 2010–REVISED AUGUST 2010

LAYOUT The power applied to AVDD should be well-regulated

and low noise. Switching power supplies and dc/dc

A precision analog component requires careful layout,

converters often have high-frequency glitches or

adequate bypassing, and clean, well-regulated power

spikes riding on the output voltage. In addition, digital

supplies. The DACx578 offers single-supply

components can create similar high-frequency spikes

operation, and is often used in close proximity with

as their internal logic switches states. This noise can

digital logic, microcontrollers, microprocessors, and

easily couple into the DAC output voltage through

digital signal processors. The more digital logic

various paths between the power connections and

present in the design and the higher the switching

analog output. As with the GND connection, AVDD

speed, the more difficult it is to keep digital noise

should be connected to a power-supply plane or trace

from appearing at the output. As a result of the single

that is separate from the connection for digital logic

ground pin of the DACx578, all return

until they are connected at the power-entry point. In

currents(including digital and analog return currents

addition, a 1µF to 10µF capacitor and 0.1µF bypass

for the DAC) must flow through a single point. Ideally,

capacitor are strongly recommended. In some

GND would be connected directly to an analog

situations, additional bypassing may be required,

ground plane. This plane would be separate from the

such as a 100µF electrolytic capacitor or even a Pi

ground connection for the digital components until

filter made up of inductors and capacitors – all

they were connected at the power-entry point of the

designed to essentially low-pass filter the supply and

system.

remove the high-frequency noise.

Product Folder Link(s): DAC5578 DAC6578 DAC7578