AD603 datasheet(19/24 Pages) AD

19 / 24 page

AD603

Rev. H | Page 19 of 24

EVALUATION BOARD

The evaluation board of the AD603 enables simple bench-top

experimenting to be performed with easy control of the

AD603. Built-in flexibility allows convenient configuration to

accommodate most operating configurations. Figure 48 is a

photograph of the AD603 evaluation board.

Figure 48. AD603 Evaluation Board

Any dual-polarity power supply capable of providing 20 mA is

all that is required, in addition to whatever test equipment the

user wishes to perform the intended tests.

Referring to the schematic in Figure 49, the input to the VGA is

single-ended, ac-coupled, and terminated in 50 Ω to accommodate

most commonly available signal generators.

GPOS

VINP

VNEG

VOUT

VPOS

GNEG

0.1µF

COMM

FDBK

V+

V–

AD603

100Ω

GNEG

V–

V+

0.1µF

0Ω

VOUT

453Ω

0.1µF

GPOS

VIN

V+

0Ω

0.1µF

V–

10µF

25V

10µF

25V

0.1µF

GND

Figure 49. Schematic of the AD603 Evaluation Board

The output is also ac-coupled and includes a 453 Ω series

resistor. The gain of the AD603 is adjusted by connecting a

voltage source between the GNEG and GPOS test loops. A 0 Ω

resistor, R5, is provided, permitting ground reference of the

differential gain control inputs. For other gain configurations, a

signal generator may be connected to the test loops, or the

GNEG and/or GPOS pins may be biased. Either pin may be

driven to either polarity within the common-mode limits of

−1.2 V to +2.0 V; therefore, to invert the gain slope, simply

consider the GPOS as the reference and drive the GNEG pin

positively with respect to GPOS.

The AD603 includes built-in gain resistors selectable at the

FDBK pin. The board is shipped with the gain at minimum,

with a 0 Ω resistor installed in R3. For maximum gain, simply

remove R3. Because of the architecture of the AD603, the

bandwidth decreases by 10, but the gain range remains at 40 dB.

Intermediate gain values may be selected by installing a resistor

between the VOUT and FDBK pins.

Figure 50, Figure 51, and Figure 52 show the component and

circuit side copper patterns and silkscreen. A bill of materials is

shown in Table 5.

Figure 50. Component Side Copper

Figure 51. Circuit Side Copper

AD603 Datasheet(PDF) 19 Page - Analog Devices

AD603 Datasheet(HTML) 19 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Datasheet Download

Link URL