AD8351

Data Sheet

Rev. D | Page 18 of 19

Table 6. Evaluation Board Configuration Options

Component

Function

Default Condition

P1-1, P1-2,

VPOS, AGND

Supply and Ground Pins.

Not Applicable

P1-3

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

common-mode voltage.

Not Applicable

W1, R7, P1-4,

R17, R18

Device Enable. Configured such that switch W1 disables the device when Pin 1 is set to

ground. Device can be disabled remotely using Pin 4 of header P1.

W1 = Installed

R7 = 0 Ω (Size 0603)

R17 = R18 = 0 Ω (Size 0603)

R2, R3, R4, R5,

R8, R12, T1, C4,

C5

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

interface for single-ended applications. T1 is a 1-to-1 impedance ratio balun used to

transform a single-ended input into a balanced differential signal. R2 and R4 are used

to provide a differential 50 Ω input termination. R5 and R8 can be increased to reduce

gain peaking when driving from a high source impedance. The 50 Ω termination

provides an insertion loss of 6 dB. C4 and C5 are used to provide ac coupling.

R2 = R4 = 24.9 Ω (Size 0805)

R3 = Open (Size 0603)

R5 = R8 = R12 = 0 Ω (Size 0603)

C4 = C5 = 10 0 nF (Size 0603)

T1 = Macom™ ETC1-1-13

R9, R10, R11,

R13, R14, R15,

R16, T2, C4, C5,

C6, C7

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

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

transform a balanced differential signal into a single-ended signal. R9, R10, and R11 are

provided for generic placement of matching components. R15 and R16 allow additional

output series resistance when driving capacitive loads. The evaluation board is configured

to provide a 150 Ω to 50 Ω impedance transformation with an insertion loss of 9.9 dB.

C4 through C7 are used to provide ac coupling.

R9 = R10 = 61.9 Ω (Size 0603)

R11 = 61.9 Ω (Size 0603)

R13 = Open (Size 0603)

R14 = 0 Ω (Size 0603)

R15 = R16 = 0 Ω (Size 0402)

C4 = C5 = 100 nF (Size 0603)

C6 = C7 = 100 nF (Size 0603)

T2 = Macom ETC1-1-13

R1

Gain Setting Resistor. Resistor R1 is used to set the gain of the device. Refer to Figure 5

when selecting gain resistor. When R1 is 100 Ω, the overall system gain of the

evaluation board is approximately −6 dB.

R1 = 100 Ω (Size 0603)

C2

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

C2 = 100 nF (Size 0805)

R6, C3, P1-3

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

applying a voltage to Pin 3 of header P1, the output common-mode voltage can be

directly adjusted. Typically decoupled to ground using a 0.1 μF capacitor.

R6 = 0 Ω (Size 0603)

C3 = 0.1 μF (Size 0805)

T3, T4, C9, C10

Calibration Networks. Calibration path provided to allow for compensation of the

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

T3 = T4 = Macom ETC1-1-13

C9 = C10 = 100 nF (Size 0603)