ADL5310

Rev. A | Page 17 of 20

EVALUATION BOARD

An evaluation board is available for the ADL5310 (Figure 40 shows the schematic). It can be configured for a wide variety of experiments.

The gain of each buffer amp is factory-set to unity, providing a slope of 200 mV/dec, and the intercept is set to 300 pA. Table 4 describes

the various configuration options.

Table 4. Evaluation Board Configuration Options

Component

Function

Default Condition

P1

Supply Interface. Provides access to the Supply Pins VNEG, COMM, and

VPOS.

P1 = installed

P2, R1, R3, R8, R9,

R17, R22, R25, R30

Monitor Interface. By adding 0 Ω resistors to R1, R3, R8, R9, R17, R22, and

R25, the VRDZ, VREF, VSUM, BIN1, BIN2, OUT1, and OUT2 pin voltages

can be monitored using a high impedance probe. VBIAS allows for the

external bias voltages to be applied to J1 and J2. If R30 = 0 Ω,

VBIAS = VREF.

P2 = not installed

R1 = R3 = R8 = open (size 0402)

R9 = R17 = open (size 0402)

R22 = R25 = R30 = open (size 0402)

R5, R6, R7, R16,

R18, R19, R20,

R21, R31, R32, C4,

C14, C15, C16,

C19, C20

Buffer Amplifier/Output Interface. The logarithmic slopes of the ADL5310

can be altered using each buffer’s gain-setting resistors, R5 and R6, and

R18 and R19. R7, R16, R31, R32, C19, and C20 allow for variation in the

buffer loading. R20, R21, C4, C14, C15, and C16 are provided for a variety

of filtering applications.

R5 = R19 = 0 Ω (size 0402)

R7 = R16 = 0 Ω (size 0402)

R20 = R21 = 0 Ω (size 0402)

R6 = R18 = open (size 0402)

R31 = R32 = open (size 0402)

C4 = C14 = open (size 0402)

C19 = C20 = open (size 0402)

C15 = C16 = open (size 0402)

LOG1 = OUT1 = installed

LOG2 = OUT2 = installed

R2, R28, R29

Intercept Adjustment. The voltage dropped across Resistors R28 and R29

determines the intercept reference current for each log amp, nominally

set to 3 µA using a 665 kΩ 1% resistor. R2 can be used to adjust the

output offset voltage at the LOG1 and LOG2 outputs.

R28 = R29 = 665 kΩ (size 0402)

R2 = 0 Ω (size 0402)

R4, R10, R11, C2,

C3, C5, C6, C8, C9

Supply Decoupling.

C2 = C5 = C9 = 100 pF (size 0402)

C3 = C6 = C8 = 0.01 µF (size 0402)

R4 = R10 = R11 = 0 Ω (size 0402)

C1, C7

Filtering VSUM.

C1 = C7 = 0.01 µF (size 0402)

R12, R13, R14,

R15, C10, C11,

C12, C13

Input Compensation. Provides essential HF compensation at the Input

Pins INP1, INP2, IRF1, and IRF2.

R12 = R15 = 1 kΩ (size 0402)

R13 = R14 = 2 kΩ (size 0402)

C10 = C13 = 1 nF (size 0402)

C11 = C12 = 4.7 nF (size 0402)

IREF, INPT

Input Interface. The test board is configured to accept current through the

SMA connectors labeled INP1 and INP2. Through-holes are provided to

connect photodiodes in place of the INP1 and INP2 SMAs for optical

interfacing. By removing R28 (R29 for INP2), a second current can be

applied to the IRF1 (IRF2 for INP2) input (also SMA) for evaluating the

ADL5310 in log ratio applications.

IREF = INPT = installed

J1, J2

SC-Style Photodiode. Provides for the direct mounting of SC-style

photodiodes.

J1 = J2 = open