REV. 0

–20–

AD8347

Table I. Evaluation Board Configuration Options

Component

Function

Default Condition

TP1, TP4, TP5

Power Supply and Ground Vector Pins

Not Applicable

TP2, TP6

IOFS and QOFS Probe Points

Not Applicable

TP3

VREF Probe Point

Not Applicable

LK1, J11

Baseband Amplifier Output Bias: Installing this link connects VREF

LK1 Installed

to VCMO. This sets the bias level on the baseband amplifiers to VREF,

which is equal to approximately 1 V. Alternatively, the bias level of the

baseband amplifiers can be set by applying an external voltage to SMA

connector J11.

LK2, LK6, LK3, J9, J10

AGC Mode: Installing LK2 and LK6 connects the mixer outputs IMXO

LK2, LK6, LK3 Installed

and QMXO to the detector inputs VDT2 and VDT1. By installing LK3,

which connects VGIN to VAGC, the AGC mode is activated. The AGC

voltage can be observed on SMA connector J9. With LK3 removed, the

gain control signal for the internal variable gain amplifiers should be

applied to SMA connector J10.

LK4, LK5

Baseband Filtering: Installing LK4 and LK5, connects the mixer

LK4, LK5 Installed

R6, R33,

outputs IMXO and QMXO directly to the baseband amplifier inputs

R6 = R33 = 0

Ω (Size 0603)

L1–L5

IAIN and QAIN. With R6 and R33 installed (0

Ω), IAIN and QAIN

L1–L5 = Open (Size 0805)

C4, C17–C22, C25–C31

can be observed on SMA connectors J7 and J8. By removing LK4 and LK5

C4, C17–C22, C25–C31 =

R8, R34, R39, R40

and installing R8 and R34, LC filters can be inserted between the

Open (Size 0805)

mixer outputs and the baseband amplifier inputs. R8 and R34 can be

R8 = R34 = Open (0603)

used to increase the effective output impedance of IMXO and QMXO.

R39 = R40 = Open (0603)

(These outputs have low output impedances.) R39 and R40 can be used

to provide terminations for the filter at IAIN and QAIN. (IAIN and QAIN

are high impedance inputs.) R39 and R40 are terminated to VREF.

R35, R36, R37, R38

Baseband Amplifier Output Series Resistors

R35 = R36 = R37 = R38 =

0

Ω (Size 0603)

SW1

SW1 = A

and the AD8347 is in operating mode. In position B, the ENBL pin is

grounded, putting the device in power-down mode.

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

28-Lead TSSOP

(RU-28)

0.177 (4.50)

0.169 (4.30)

28

15

14

1

0.386 (9.80)

0.378 (9.60)

0.256 (6.50)

0.246 (6.25)

PIN 1

SEATING

PLANE

0.006 (0.15)

0.002 (0.05)

0.0118 (0.30)

0.0075 (0.19)

0.0256 (0.65)

BSC

0.0433 (1.10)

MAX

0.0079 (0.20)

0.0035 (0.090)

0.028 (0.70)

0.020 (0.50)

8

0