ADA4310-1

Rev. 0 | Page 12 of 16

BOARD LAYOUT

As is the case with all high speed applications, careful attention

to printed circuit board layout details prevents associated board

parasitics from becoming problematic. Proper RF design

technique is mandatory. The PCB should have a ground plane

covering all unused portions of the component side of the

board to provide a low impedance return path. Removing the

ground plane on all layers from the area near the input and

output pins reduces stray capacitance, particularly in the area of

the inverting inputs. Signal lines connecting the feedback and

gain resistors should be as short as possible to minimize the

inductance and stray capacitance associated with these traces.

Termination resistors and loads should be located as close as

possible to their respective inputs and outputs. Input and output

traces should be kept as far apart as possible to minimize

coupling (crosstalk) though the board. Wherever there are

complementary signals, a symmetrical layout should be

provided to the extent possible to maximize balanced

performance. When running differential signals over a long

distance, the traces on the PCB should be close. This reduces

the radiated energy and makes the circuit less susceptible to RF

interference. Adherence to stripline design techniques for long

signal traces (greater than about 1 inch) is recommended.

For more information on high speed board layout, go to

www.analog.com and A Practical Guide to High-Speed Printed-

Circuit-Board Layout.

POWER SUPPLY BYPASSING

The ADA4310-1 operates on supplies, from +5 V to ±6 V. The

ADA4310-1 circuit should be powered with a well-regulated

power supply. Careful attention must be paid to decoupling the

power supply. High quality capacitors with low equivalent series

resistance (ESR), such as multilayer ceramic capacitors

(MLCCs), should be used to minimize supply voltage ripple and

power dissipation. In addition, 0.1 μF MLCC decoupling

capacitors should be located no more than ⅛-inch away from

each of the power supply pins. A large, usually tantalum, 10 μF

capacitor is required to provide good decoupling for lower

frequency signals and to supply current for fast, large signal

changes at the ADA4310-1 outputs. Bypassing capacitors should

be laid out in such a manner to keep return currents away from

the inputs of the amplifiers. This minimizes any voltage drops

that can develop due to ground currents flowing through the

ground plane. A large ground plane also provides a low

impedance path for the return currents.