BurrBrown Products

from Texas Instruments

VCA822

VCA822

1

FEATURES

DESCRIPTION

APPLICATIONS

R

F

+V

IN

R

G+

R

G-

FB

R

S

20W

V

IN1

VCA822

R

G

R

1

C

1

R

S

V

IN2

R

L

C

L

V

OUT

9

6

-24

Frequency(Hz)

1M

1G

3

-21

-3

0

100M

10M

-18

-15

-12

-9

-6

InitialFrequencyResponse

ofVCA822withRCLoad

EqualizedFrequency

Response

R =75

C =100pF

W

L

F

VCA822

SBOS343A – SEPTEMBER 2007 – REVISED OCTOBER 2007

Wideband, > 40dB Gain Adjust Range, Linear in V/V

VARIABLE GAIN AMPLIFIER

23

• 150MHz SMALL-SIGNAL BANDWIDTH

The VCA822 is a dc-coupled, wideband, linear in V/V,

(G = +10V/V)

continuously

variable,

voltage-controlled

gain

• 137MHz, 5V

amplifier.

It

provides

a

differential

input

to

• 0.1dB GAIN FLATNESS to 28MHz

single-ended conversion with a high-impedance gain

• 1700V/µs SLEW RATE

control input used to vary the gain down 40dB from

the nominal maximum gain set by the gain resistor

• > 40dB GAIN ADJUST RANGE

• HIGH GAIN ACCURACY: 20dB ±0.3dB

The VCA822 internal architecture consists of two

• HIGH OUTPUT CURRENT: ±160mA

input buffers and an output current feedback amplifier

stage integrated with a multiplier core to provide a

complete variable gain amplifier (VGA) system that

• DIFFERENTIAL LINE RECEIVERS

does not require external buffering. The maximum

• DIFFERENTIAL EQUALIZERS

gain is set externally with two resistors, providing

flexibility in designs. The maximum gain is intended

• PULSE AMPLITUDE COMPENSATION

to be set between +2V/V and +100V/V. Operating

• VARIABLE ATTENUATORS

from ±5V supplies, the gain control voltage for the

• VOLTAGE-TUNABLE ACTIVE FILTERS

VCA822 adjusts the gain linearly in V/V as the control

• DROP-IN UPGRADE TO LMH6503

voltage varies from +1V to –1V. For example, set for

a maximum gain of +10V/V, the VCA822 provides

10V/V, at +1V input, to 0.1V/V at –1V input of gain

control range. The VCA822 offers excellent gain

linearity.

For

a

20dB

maximum

gain,

and

a

gain-control input voltage varying between 0V and

1V, the gain does not deviate by more than ±0.3dB

(maximum at +25

°C).

Table 1. VCA822 RELATED PRODUCTS

GAIN

ADJUST

INPUT

SIGNAL

RANGE

NOISE

BANDWIDTH

Figure 1. Differential Equalizer

SINGLES

DUALS

(dB)

(nV/

√Hz)

(MHz)

VCA810

—

80

2.4

35

—

VCA2612

45

1.25

80

—

VCA2613

45

1

80

—

VCA2615

52

0.8

50

—

VCA2617

48

4.1

50

VCA820

—

40

8.2

150

VCA821

—

40

7.0

420

VCA822

—

40

8.2

150

VCA824

—

40

7.0

420

Figure 2. Differential Equalization of an RC Load

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

X2Y is a trademark of X2Y Corporation.

3

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2007, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.