ADA4945-1ACPZ-R2 datasheet(43/44 Pages) AD

43 / 44 page

Data Sheet

ADA4945-1

Rev. 0 | Page 43 of 44

LAYOUT, GROUNDING, AND BYPASSING

As a high speed device, the ADA4945-1 is sensitive to the PCB

environment in which it operates. Using the superior performance

of the ADA4945-1 requires attention to the details of high speed

PCB design.

Ensure that signal routing is short and direct to avoid parasitic

effects. Wherever complementary signals exist, provide a

symmetrical layout to maximize balanced performance. When

routing differential signals over a long distance, ensure that

PCB traces are close together, and twist any differential wiring

such that loop area is minimized. This configuration reduces

radiated energy and makes the circuit less susceptible to

interference.

Bypass the power supply pins as near to the device as possible

and directly to a nearby ground plane. Use high frequency ceramic

chip capacitors. Use two parallel bypass capacitors (0.1 µF and

10 µF) for each supply. Place the 0.1 µF capacitor as near to the

device as possible. Further away, provide low frequency

bypassing using 10 µF tantalum capacitors from each supply to

ground.

The ground plane must be as continuous and unbroken as

possible to provide a low impedance path for return currents to

the supply. As such, the ground plane should be kept free of any

signal traces or other interruptions.

ADA4945-1ACPZ-R2 数据表(PDF) 43 Page - Analog Devices