AD8375

Rev. 0 | Page 20 of 24

Table 6. Evaluation Board Configuration Options

Components

Function

Default Conditions

C13, C14, C20,

C63, C64, R91

Power Supply Decoupling. Nominal supply decoupling consists a 10 μF

capacitor to ground followed by 0.1 μF capacitors to ground positioned as

close to the device as possible.

C20 = 10 μF (size 3528)

C13, C14, C63, C64 = 0.1 μF

(size 0402)

R91 = 0 Ω (size 0402)

T1, C1, C2, C60,

R1, R2, R9, R10,

R70 to R72

Input Interface. T1 is a 3:1 impedance ratio balun to transform a 50 Ω single-

ended input into a 150 Ω balanced differential signal. R2 grounds one side of

the differential drive interface for single-ended applications. R9, R10, and R70

to R72 are provided for generic placement of matching components. C1 and

C2 are dc blocks.

T1 = TC3-1+ (Mini-Circuits)

C1, C2, C60 = 0.1 μF (size 0402)

R2, R9, R10 = 0 Ω (size 0402)

R1, R70 to R72 = open (size 0402)

T3, C7, C8, C62

L1, L2, R15, R16,

R19, R20, R23 to R25,

R29, R30, R62

Output Interface. C7 and C8 are dc blocks. L1 and L2 provide dc biases for the

output. R19, R20, and R23 to R25 are provided for generic placement of

matching components. The evaluation board is configured to provide a 150 Ω

to 50 Ω impedance transformation with an insertion loss of about 11 dB. T3 is

a 1:1 impedance ratio balun to transform the balanced differential signal to a

single-ended signal. R30 grounds one side of the differential output interface

for single-ended applications.

T3 = ETC1-1-13 (M/A-COM)

C7, C8, C62 = 0.1 μF (size 0402)

L1, L2 = 1 μH (size 0805)

R19, R20 = 61.9 Ω (size 0402)

R23, R25 = 30.9 Ω (size 0402)

R15, R16 = 0 Ω (size 0603)

R30 = 0 Ω (size 0402)

R24, R29, R62 = open (size 0402)

PU, R13, C5

Enable Interface. The AD8375 is enabled by applying a logic high voltage to

the PWUP pin. The device is disabled when the PU switch is set in the position

closest to the PU label, connecting the PWUP pin to ground. The device is

enabled when the PU switch is set in the opposite position, connecting the

PWUP to VPOS.

PU = installed

R13 = 0 Ω (size 0603)

C5 = open (size 0603)

WA0 to WA4

Parallel Interface Control. Used to hardwire A0 through A4 to the desired gain.

The bank of switches, WA4 to WA0, set the binary gain code. WA4 represents

the LSB. WA0 represents the MSB.

WA0 to WA4 = installed

C11

Voltage Reference. Input common-mode voltage ac-coupled to ground by

0.1 μF capacitor, C11.

C11 = 0.1 μF (size 0402)