REV. B

AD8351

–15–

Table III. Evaluation Board Configuration Options

Component

Function

Default Condition

P1-1, P1-2,

Supply and Ground Pins.

Not Applicable

VPOS, AGND

P1-3

Common-Mode Offset Pin. Allows for monitoring or adjustment of the

Not Applicable

output common-mode voltage.

W1, R7, P1-4, R17, R18

Device Enable. Configured such that switch W1 disables the device when

W1 = Installed

Pin 1 is set to ground. Device can be disabled remotely using Pin 4 of

R7 = 0

Ω (Size 0603)

header P1.

R17 = R18 = 0

Ω (Size 0603)

R2, R3, R4, R5, R8, R12,

Input Interface. R3 and R12 are used to ground one side of the differential

R2 = R4 = 24.9

Ω (Size 0805)

T1, C4, C5

drive interface for single-ended applications. T1 is a 1-to-1 impedance ratio R3 = Open (Size 0603)

balun used to transform a single-ended input into a balanced differential

R5 = R8 = R12 = 0

Ω

signal. R2 and R4 are used to provide a differential 50

Ω input termination. (Size 0603)

R5 and R8 can be increased to reduce gain peaking when driving from a high C4 = C5 = 10 0 nF (Size 0603)

source impedance. The 50

C4 and C5 are used to provide ac coupling.

R9, R10, R11, R13, R14,

Output Interface. R13 and R14 are used to ground one side of the differential

R9 = R10 = 61.9

Ω (Size 0603)

R15, R16, T2, C4, C5,

output interface for single-ended applications. T2 is a 1-to-1 impedance ratio

R11 = 61.9

Ω (Size 0603)

C6, C7

balun used to transform a balanced differential signal into a single-ended

R13 = Open (Size 0603)

signal. R9, R10, and R11 are provided for generic placement of matching

R14 = 0

Ω (Size 0603)

components. R15 and R16 allow additional output series resistance when

R15 = R16 = 0

Ω (Size 0402)

driving capacitive loads. The evaluation board is configured to provide a

C4 = C5 = 100 nF (Size 0603)

150

Ω to 50 Ω impedance transformation with an insertion loss of 9.9 dB.

C6 = C7 = 100 nF (Size 0603)

C4 through C7 are used to provide ac coupling.

T2 = Macom ETC1-1-13

R1

Gain Setting Resistor. Resistor R1 is used to set the gain of the device.

R1 = 100

Ω (Size 0603)

Refer to TPC 2 when selecting gain resistor. When R1 is 100

Ω, the

overall system gain of the evaluation board will be approximately –6 dB.

C2

Power Supply Decoupling. The supply decoupling consists of a 100 nF

C2 = 100 nF (Size 0805)

capacitor to ground.

R6, C3, P1-3

Common-Mode Offset Adjustment. Used to trim common-mode output

R6 = 0

Ω (Size 0603)

level. By applying a voltage to Pin 3 of header P1, the output common-

C3 = 0.1

µF (Size 0805)

mode voltage can be directly adjusted. Typically decoupled to ground

using a 0.1

µF capacitor.

T3, T4, C9, C10

Calibration Networks. Calibration path provided to allow for compensation

T3 = T4 = Macom

of the insertion loss of the baluns and the reactance of the coupling capacitors.

ETC1-1-13

C9 = C10 = 100 nF

(Size 0603)