Data Sheet

ADL5511

APPLICATIONS INFORMATION

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Rev. E | 24 of 26

The VRMS output is accessible via a clip lead (a pad is also

available where an SMA connector is installed). The VENV output

is accessible via an SMA connector. For response- time critical

measurements where stray capacitance must be minimized, R2 can

be removed and a FET probe can be attached to JP1 (JP1 must be

installed).

Figure 59. Evaluation Board Schematic

Table 5. Evaluation Board Configuration Options

Component

Description

Default Condition

VPOS, GND

Ground and supply vector pins.

Not applicable

C13, C14

Power supply decoupling. Nominal supply decoupling of 0.01 µF and 100 pF.

C13 = 100 pF (Size 0402)

C14 = 0.1 µF (Size 0402)

C17

RMS filter capacitor (FLT4). The internal rms averaging capacitor can be augmented by placing additional

capacitance in C17.

C17 = 0.1 µF (Size 0402)

R5, C1

RF input interface. The 75 Ω resistor at R5 combines with the ADL5511 internal input impedance to give a

broadband input impedance of around 50 Ω. C1 is an ac coupling capacitor, which should be chosen according

to nominal carrier frequency.

R5 = 75 Ω (Size 0402)

C1 = 100 pF (Size 0402)

R18, C9

RMS output and output filtering. The combination of C9 and the internal 100 Ω output resistance can be used to

form a low-pass filter to reduce the output noise on the VRMS output beyond the reduction due to C17 (capacitor

on FLT4). The rms output is available on the VRMS clip-on test point. To observe VRMS using an SMA cable, an

SMA connector can be soldered on to the pad labeled VRMS1.

R18 = 0 Ω (Size 0402)

C9 = open (Size 0402)

VRMS clip-on test point = installed

VRMS1 SMA connector = open

R19, C8, R2, JP1

VENV output and output filtering. The VENV output is available on the VENV SMA connector. If post-envelope

filtering is desired, R19 and C8 can be used to form a low-pass filter at the VENV output.R2 can be removed to

isolate the JP1 jumper from the VENV SMA connector and JP1 can be installed and used to interface to a FET

probe. This helps to eliminate any excessive trace and connector capacitance.

VENV SMA connector = installed

R19, R2 = 0 Ω (Size 0402)

C8 = open (Size 0402)

JP1 = open

R20, C7

Envelope reference output and output filtering. The EREF output is available on the EREF clip-on test point. The

dc reference voltage at Pin EREF can be filtered by the low-pass filter formed by the combination of R20 and

C7. To observe the EREF voltage using an SMA cable, an SMA connector can be soldered onto the pad labeled

EREF1.

R20 = 0 Ω (Size 0402)

C7 = open (Size 0402)

EREF clip-on test point = installed

EREF1 SMA connector = open