MAX9982 Evaluation Kit

2

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Quick Start

The MAX9982 EV kit is fully assembled and factory

tested. Follow the instructions in the Connections and

Setup section for proper device evaluation.

Test Equipment Required

tion of the MAX9982 EV kit. It is intended as a guide

only, and some substitutions can be made.

Connections and Setup

This section provides a step-by-step guide for testing

the basic functionality of the EV kit. As a general pre-

caution to prevent damaging the outputs by driving

high-VSWR loads,

do not turn on DC power or RF

signals until all connections are made.

This procedure is specific to operation with an RF

input-frequency range of 825MHz to 915MHz, low-side

injected LO for a 100MHz IF. Choose the test frequen-

cy based on the particular system’s frequency plan,

and adjust the following procedure accordingly. See

Figure 1 for the mixer test setup diagram.

1) Calibrate the power meter for 870MHz. For safety

margin, use a power sensor rated to at least

+20dBm, or use padding to protect the power

head as necessary.

2) Connect 3dB pads to DUT ends of each of the

three RF signal generators’ SMA cables. This

padding improves VSWR and reduces the errors

because of mismatch.

3) Use the power meter to set the RF signal genera-

tors according to the following:

• RF signal source: -5dBm into DUT at 870MHz

(approximately -2dBm before the 3dB pad)

• LO1 signal source: 0dBm into DUT at 770MHz

(approximately +3dBm before the 3dB pad)

• LO2 signal source: 0dBm into DUT at 771MHz

(approximately +3dBm before the 3dB pad)

4) Disable the signal generator outputs.

5) Connect the RF source (with pad) to RF IN.

6) Connect the LO1 and LO2 signal sources to the EV

kit LO inputs.

7) Measure loss in the 3dB pad and the cable that is

connected to IF OUT. Losses are frequency depen-

dent, so test this at 100MHz (the IF frequency).

Use this loss as an offset in all output power/gain

calculations.

8) Connect this 3dB pad to the EV kit’s IF OUT con-

nector, and connect a cable from the pad to the

spectrum analyzer.

9) Set the DC supply to +5.0V, and set a current limit

of approximately 250mA if possible. Disable the

output voltage and connect supply to the EV kit

through a low internal resistance ammeter. Enable

the supply. Re-adjust the supply to get +5.0V at the

EV kit because there will be a voltage drop across

the ammeter when the mixer is drawing current.

10) Select LO1 by leaving LO_SEL (TP3) unconnected

or connecting it to +5V. If left floating, LO_SEL pulls

high by an on-board pullup resistor.

11) Enable the LO and the RF sources.

Testing the Mixer

Adjust the center and span of the spectrum analyzer to

observe the IF output tone at 100MHz. The level should

be at approximately -5.4dBm (2.6dB conversion gain,

3dB pad loss). The spectrum analyzer’s absolute mag-

nitude accuracy is typically no better than ±1dB; there-

fore, use the power meter to get an accurate output

power measurement. There will also be a tone at

99MHz, which is due to the LO signal applied to LO2.

The amount of suppression between the 100MHz and

99MHz signals is the switch isolation.

Connect LO_SEL to GND to select LO2. Observe that

the IF output level at 99MHz increases while the

100MHz level decreases.

Detailed Description

The MAX9982 is a highly integrated downconverter. RF

and LO baluns are integrated on-chip, as well as an LO

buffer and a SPDT LO input select switch. The EV kit cir-

cuit consists mostly of supply decoupling capacitors and

DC-blocking capacitors, allowing for a simple design-in.

Table 1. Test Equipment

EQUIPMENT

QTY

DESCRIPTION

HP E3631A

1

DC power supply

Fluke 75 series II

1

Digital multimeter (ammeter)

HP/Agilent 8648B

3

RF signal generators

HP 437B

1

RF power meter

HP 8561

1

Spectrum analyzer

HP 8482A

1

High-power sensor (power head)

3dB pad

4

3dB attenuators