ADL5513

Data Sheet

Rev. A | Page 24 of 25

Table 5. Evaluation Board Configuration Options

Component

Function

Default Value

C1, C2, R1

Input interface.

The 52.3 Ω resistor in Position R1 combines with the internal input impedance of

the ADL5513 to give a broadband input impedance of about 50 Ω. C1 and C2 are

dc-blocking capacitors. A reactive impedance match can be implemented by

replacing R1 with an inductor and C1 and C2 with appropriately valued capacitors.

R1 = 52.3 Ω (Size 0402)

C1 = 47 nF (Size 0402)

C2 = 47 nF (Size 0402)

C3, C4, C5, C6,

R11, R12

Power supply decoupling.

The nominal supply decoupling consists of a 100 pF filter capacitor placed

physically close to the ADL5513 and a 0.1 µF capacitor placed nearer to the power

supply input pin. If additional isolation from the power supply is required, a small

resistance (R11 or R12) can be installed between the power supply and the

ADL5513.

C3 = 0.1 µF (Size 0402)

C4 = 100 pF (Size 0402)

C5 = 100 pF (Size 0402)

C6 = 0.1 µF (Size 0402)

R11 = 0 Ω (Size 0402)

R12 = 0 Ω (Size 0402)

C7

Filter capacitor.

The low-pass corner frequency of the circuit that drives the VOUT pin can be

lowered by placing a capacitor between CLPF and ground. Increasing this

capacitor increases the overall rise/fall time of the ADL5513 for pulsed input

signals.

C7 = 1000 pF (Size 0402)

R2, R3 R4, R5, R10, RL, CL

Output interface—measurement mode.

In measurement mode, a portion of the output voltage is fed back to the VSET pin via

as a back-terminating resistor or as part of a single-pole, low-pass filter. If a

reduction in slope is desired, a voltage divider can be installed at the output using

R3 and RL.

R2 = open (Size 0402)

R3 = 1 kΩ (Size 0402)

R4 = 0 Ω (Size 0402)

R5 = open (Size 0402)

R10 = open (Size 0402)

RL = CL = open (Size 0402)

Output interface—controller mode.

In controller mode, the ADL5513 can control the gain of an external component.

To allow for this, remove the R4 resistor. A setpoint voltage is applied to Pin VSET.

The value of this setpoint voltage corresponds to the desired RF input signal level

applied to the ADL5513 RF input. A sample of the RF output signal from this variable

gain component is applied to the ADL5513 input by a directional coupler. The

voltage at the VOUT pin is applied to the gain control of the variable gain element.

The magnitude of the control voltage can optionally be reduced via a voltage

divider comprising R3 and RL, or a low-pass filter can be installed using R3 and CL.

R2 = open (Size 0402)

R3 = 1 kΩ (Size 0402)

R4 = open (Size 0402)

R5 = open (Size 0402)

R10 = 0 Ω (Size 0402)

RL = CL = open (Size 0402)

R6, R7, R8, R9

Temperature compensation interface.

A voltage source can be used to optimize the temperature performance for various

input frequencies. The pads for R8 and R9 can be used for a voltage divider from

R6 = open (Size 0402)

R7 = 0 Ω (Size 0402)

R8 = open (Size 0402)

R9 = open Ω (Size 0402)