MAX3654_1 datasheet(2/5 Pages) MAXIM

2 / 5 page

MAX3654 Evaluation Kit

2 _________________________________________________________________________________________

_____________Component Suppliers

SUPPLIER

PHONE

WEBSITE

AVX

803-448-9411

www.avxcorp.com

Pulse

Engineering

858-674-8100

www.pulseeng.com

Murata

770-436-1300

www.murata.com

Note: Please indicate that you are using the MAX3654 when

contacting these component suppliers.

________________________Quick Start

Optical Evaluation

1) Attach triplexer photodiode to IN+ and IN- of the

MAX3654. The cathode normally connects to IN+.

The photodiode case should be grounded to the

most convenient ground via. Make certain that the

anode and cathode leads are symmetric in length

and orientation, lead lengths should normally be

about 5mm.

2) Set JU2 to R4 to manually adjust the gain with an

input from 0 to 1.4V on TP3.

3) Leave JU3 open for minimum hysteresis.

4) Set JU1 to R8 to enable the output signal.

5) Connect the signal output at J2 to a 75

spectrum-analyser input. A minimum loss pad may

also be used to connect J2 to 50

Ω test equipment.

6) Connect a +5V supply to the VCC terminal, TP1

and ground to the GND terminal, TP2.

7) Connect the photodiode bias supply to TP13.

Typically use +12V bias supply, or as required by

the photodiode.

Electrical Evaluation

Connect a 50

Ω signal source to IN at J3. Set the

input signal level to PIN = -18dBm, so that the

voltage on 50

Ω produces the maximum input

level of 1.6mAP-P.

Connect the RF output at J4 to a 75Ω spectrum

analyser input. A minimum loss pad may also be

used to connect J4 to 50

Ω test equipment.

Leave JU6 open for minimum hysteresis.

Set JU5 to R20 to enable output.

Connect a +5V supply to the VCC terminal, TP7

and ground to the GND terminal, TP8.

Apply 1.4V to TP12 to set the MAX3654 gain to

minimum, 43.5dBΩ. A voltage from 0.175V to

1.4V at TP12 adjusts the gain from 62dBΩ to

43.5dBΩ

Input and Output Signal Levels

When used in the electrical input configuration shown

in Figure 2, the MAX3654 is intended to operate with

AC input signal current from 175

μAP-P to 1.6mAP-P. The

corresponding electrical input is -37dBm (0 < VAGC <

0.175V) to -18dBm (VAGC = 1.4V), on 50

Ω. The

MAX3654 EV Kit can also be configured to provide

Ω input impedance by replacing R12 and R13 with

Ω resistors.

When used in the optical input configuration shown in

Figure 2, JU2 may be connected to R3 to configure the

MAX3654 for AGC operation based on the average

optical power level. In this case, the MAX3654

transimpedance is controlled by the average optical

power level, as measured by the voltage across R21.

The values of R1, R21 and R22 shown in Figure 1 will

provide an output level of 15dBmV/ch (+1dB) for

optical input signals ranging from -6dBm to +2dBm,

(OMI = 3.5%, N = 129) using a typical triplexer

photodiode. The total output signal level in this case is

15dBmV/ch + 10 log(129 channels) = 36dBmV, which

is the maximum operating level at which the specified

linearity will be achieved. Operating at higher outputs

may reduce MAX3654 performance.

Operating conditions (OMI, number of channels,

responsivity, etc) change the VAGC setting required for

a given output voltage. EV Kit AGC circuit gain can be

increased by adding a voltage-divider, R22, to the

op amp. To reduce gain the values of R1 and R21

should both be increased. Remember to keep the total

output at 36dBmV or less to maintain the desired

MAX3654 performance.

Photodiode Lead Configuration

Photodiode lead parasitic impedances can significantly

effect performance of the MAX3654. It is especially

important that the anode and cathode connections are

electrically symmetric. Refer to Figure 1 in the

MAX3654 data sheet. Note that the EV Kit layout is

designed to minimize capacitance to ground in the

input signal path.

MAX3654 Datasheet(PDF) 2 Page - Maxim Integrated Products

MAX3654 Datasheet(HTML) 2 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5

Datasheet Download

Link URL