Datasheet

DAC7565

SBAS412B –FEBRUARY 2008–REVISED MARCH 2011

www.ti.com

LAYOUT The power applied to V

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.

components can create similar high-frequency spikes

as their internal logic switches states. This noise can

The DAC7565 offers single-supply operation, and is

easily couple into the DAC output voltage through

often used in close proximity with digital logic,

various paths between the power connections and

microcontrollers, microprocessors, and digital signal

analog output.

processors. The more digital logic present in the

design and the higher the switching speed, the more

As with the GND connection, V

should be

difficult it is to keep digital noise from appearing at

connected to a power-supply plane or trace that is

the output.

separate from the connection for digital logic until

they are connected at the power-entry point. In

As a result of the single ground pin of the DAC7565,

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

all return currents (including digital and analog return

capacitor are strongly recommended. In some

currents for the DAC) must flow through a single

situations, additional bypassing may be required,

point. Ideally, GND would be connected directly to an

such as a 100μF electrolytic capacitor or even a Pi

analog ground plane. This plane would be separate

filter made up of inductors and capacitors—all

from the ground connection for the digital

designed to essentially low-pass filter the supply and

components until they were connected at the

remove the high-frequency noise.

power-entry point of the system.

Product Folder Link(s): DAC7565