Single/Dual/Quad, 270MHz, 1mA, SOT23,

Current-Feedback Amplifiers with Shutdown

16

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• Do not make 90° turns; round all corners.

• Observe high-frequency bypassing techniques to

maintain the amplifiers’ accuracy. The bypass cap-

acitors should include a 0.01µF to 0.1µF ceramic

capacitor between each supply pin and the ground

plane, located as close to the package as possible.

• Place a 1µF ceramic capacitor in parallel with each

0.01µF to 0.1µF capacitor, as close to them as

possible.

• Place a 10µF to 15µF low-ESR tantalum at the point

of entry to the power-supply pins’ PC board. The

power-supply trace should lead directly from the

• Keep PC traces short and use surface-mount com-

ponents to minimize parasitic inductance.

Maxim’s High-Speed Evaluation Board

Figures 2 and 3 show layouts of Maxim’s high-speed

single SOT23 and SO evaluation boards. These boards

were developed using the techniques described

above. The smallest available surface-mount resistors

were used for feedback and back-termination

to minimize their distance from the part, reducing the

capacitance associated with longer lead lengths.

SMA connectors were used for best high-frequency

performance. Because distances are extremely short,

performance is unaffected by the fact that inputs and

outputs do not match a 50

Ω line. However, in applica-

tions that require lead lengths greater than one-quarter

of the wavelength of the highest frequency of interest,

use constant-impedance traces.

Fully assembled evaluation boards are available for the

MAX4180ESA.

Figure 2a. SOT23 High-Speed EV Board

Component Placement Guide—

Component Side

Figure 2b. SOT23 High-Speed EV Board

Layout—Component Side

Figure 2c. High-Speed EV Board

Layout—Solder Side

Figure 3a. SO-8 High-Speed EV Board

Component Placement Guide—

Component Side

Figure 3b. SO-8 High-Speed EV Board

Layout—Component Side

Figure 3c. SO-8 High-Speed EV Board

Layout—Solder Side