Datasheet

DAC7564

SBAS413B –FEBRUARY 2008–REVISED MAY 2011

www.ti.com

LAYOUT

A precision analog component requires careful layout, The power applied to V

should be well-regulated

adequate bypassing, and clean, well-regulated power and low noise. Switching power supplies and dc/dc

supplies. converters often have high-frequency glitches or

spikes riding on the output voltage. In addition, digital

The DAC7564 offers single-supply operation, and is

components can create similar high-frequency spikes

often used in close proximity with digital logic,

as their internal logic switches states. This noise can

microcontrollers, microprocessors, and digital signal

easily couple into the DAC output voltage through

processors. The more digital logic present in the

various paths between the power connections and

design and the higher the switching speed, the more

analog output.

difficult it is to keep digital noise from appearing at

the output. As with the GND connection, V

should be

connected to a power-supply plane or trace that is

As a result of the single ground pin of the DAC7564,

separate from the connection for digital logic until

all return currents (including digital and analog return

they are connected at the power-entry point. In

currents for the DAC) must flow through a single

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

point. Ideally, GND would be connected directly to an

capacitor are strongly recommended. In some

analog ground plane. This plane would be separate

situations, additional bypassing may be required,

from the ground connection for the digital

such as a 100μF electrolytic capacitor or even a Pi

components until they were connected at the

filter made up of inductors and capacitors—all

power-entry point of the system.

designed to essentially low-pass filter the supply and

remove the high-frequency noise.