2) Connect VCC to the shutdown test port (TP1).

3) Turn on the DC supply; the supply current should

read approximately 14mA.

4) To test the shutdown current, repeat Steps 1, 2, and

3 with shutdown connected to GND.

Testing the Power Gain

1) Connect a DC supply set to +3.0V (through an

ammeter if desired) to the VCC and GND terminals

on the EV kit. If available, set the current limit to

30mA. Do not turn on the supply.

2) Gain can be determined with a network analyzer.

This has the advantage of displaying gain over a

swept frequency band, in addition to displaying

input and output return loss. Refer to the network

analyzer manufacturer’s user manual for setup

details.

3) (Optional) Connect one RF signal generator to the

RFIN SMA connector. Do not turn on the generator’s

output. Set the generator to an output frequency of

5250MHz, and set the generator power level to

-30dBm.

4) (Optional) Connect the spectrum analyzer to the

RFOUT SMA connector. Set the spectrum analyzer

to a center frequency of 5250MHz and a total span

of 20MHz.

5) (Optional) Turn on the DC supply, and then activate

the RF generator’s output. A 5250MHz signal shown

on the spectrum analyzer display should indicate a

magnitude of approximately -15dBm. Account for

cable losses (between 0.5dB and 2dB) and circuit

board losses (approximately 0.5dB) when comput-

ing gain.

Testing the Noise Figure

Noise-figure measurements on low-noise devices such as

the MAX2649 are extremely sensitive to lab setup, board

losses, and parasitics. There are many techniques and

precautions for measuring a low noise-figure device.

Detailed explanation of these items goes beyond the

scope of this document. For more information on how to

perform this level of noise-figure measurement, refer to

Agilent Technologies Application Note 57-2, Noise Figure

Measurement Accuracy.

Layout

The EV kit’s PC board can serve as a guide for laying

out a board using the MAX2649.

Design the layout as compact as possible to minimize

board parasitics. Install capacitors as close as possible

to the IC supply-voltage pin. Place the ground end of

these capacitors near the IC GND pins to provide a

low-impedance return path for the signal current.

Connect multiple vias from the ground plane as close

as possible to the ground pins. When using a UCSP

package, round or square pads are permissible.

For the power supplies, a star topology works well to

isolate different sections of the device. Each VCC node

has its own path to a central VCC. Place decoupling

capacitors that provide low impedance at the RF

frequency of interest close to all VCC connections. The

central VCC should have a large decoupling capacitor

as well.

For the best gain and noise performance, use high-Q

(40) components for the LNA input-matching circuit.

MAX2649 Evaluation Kit

2

_______________________________________________________________________________________

MAX2649

J3

J4

J1

RFIN

VCC

C9

0.01

µF

C8

100pF

C2

0.75pF

C3

22pF

C5

20pF

C6

3.9pF

C1

3.9pF

50

Ω

TRANSMISSION

LINE

TP1

SHUTDOWN

R2

100

Ω

R3

200

Ω

L2

1.2nH

C4

3.9pF

RFOUT

J2

L1

1.2nH

L3

22nH

C7

1pF

C10

8.2pF

RFIN

GND

RFOUT

GND

SHDN

U1

Figure 1. MAX2649 EV Kit Schematic