AD8351ARMZ Datasheet, PDF (15/16 Pages) Analog Devices – Low Distortion Differential RF/IF Amplifier

AD8351
Table III. 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
R2, R3, R4, R5, R8, R12,
T1, C4, C5
R9, R10, R11, R13, R14,
R15, R16, T2, C4, C5,
C6, C7
R1
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)
Input Interface. R3 and R12 are used to ground one side of the differential R2 = R4 = 24.9 Ω (Size 0805)
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 Ω termination provides an insertion loss of 6 dB. T1 = Macom^TM ETC1-1-13
C4 and C5 are used to provide ac coupling.
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
Gain Setting Resistor. Resistor R1 is used to set the gain of the device.
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.
R1 = 100 Ω (Size 0603)
C2
R6, C3, P1-3
Power Supply Decoupling. The supply decoupling consists of a 100 nF
capacitor to ground.
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.
C2 = 100 nF (Size 0805)
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)
REV. B
–15–