Burr Brown VCA2612Y-2K, VCA2612Y Datasheet

1

®

VCA2612

FEATURES

● LOW NOISE PREAMP:

• Low Input Noise: 1.25nV/√Hz

• Active Termination Noise Reduction

• Switchable Termination Value

• 80MHz Bandwidth

• 5dB to 25dB Gain

• Differential Input/Output

● LOW NOISE VARIABLE GAIN AMPLIFIER:

• Low Noise VCA: 3.3nV/√Hz, Differential

Programming Optimizes Noise Figure

• 24dB to 45dB Gain

• 40MHz Bandwidth

• Differential Input/Output

● LOW CROSSTALK:

52dB at Max Gain, 5MHz

● HIGH-SPEED VARIABLE GAIN ADJUST

● SWITCHABLE EXTERNAL PROCESSING

APPLICATIONS

● ULTRASOUND SYSTEMS

● WIRELESS RECEIVERS

● TEST EQUIPMENT

VCA2612

®

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Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

© 2000 Burr-Brown Corporation PDS-1541B Printed in U.S.A. March, 2000

TM

Dual, VARIABLE GAIN AMPLIFIER

with Low Noise Preamp

VCA2612

For most current data sheet and other product

information, visit www.burr-brown.com

Low Noise

Preamp

5dB to 25dB

Programmable

Gain Amplifier

24 to 45dB

Voltage
Controlled
Attenuator

Analog

Control

Maximum Gain

Select

RF

2

RF

1

FB

FBSW

LNP

IN

P

LNP

IN

N

LNP

GS1

LNP

GS2

LNP

GS3

LNP

Gain Set

Input

LNP

OUT

P

SEL

VCAINP

LNP

OUT

N VCAINN VCA

CNTL

FB

CNTL

VCA

OUT

P

VCA

OUT

N

MGS

1

MGS2MGS

3

Maximum Gain Select

VCA2612

(1 of 2 Channels)

DESCRIPTION

The VCA2612 is a highly integrated, dual receive chan­nel, signal processing subsystem. Each channel of the
product consists of a low noise pre-amplifier (LNP) and
a Variable Gain Amplifier (VGA). The LNP circuit
provides the necessary connections to implement Active
Termination (AT), a method of cable termination which
results in up to 4.6dB noise figure improvement. Differ­ent cable termination characteristics can be accommo­dated by utilizing the VCA2612’s switchable LNA feed­back pins. The LNP has the ability to accept both
differential and single ended inputs, and generates a
differential output signal. The LNP provides strappable
gains of 5dB, 17dB, 22dB and 25dB.

The output of the LNP can be accessed externally for
further signal processing, or fed directly into the VGA.
The VCA2612’s VGA section consists of two parts, the
Voltage Controlled Attenuator (VCA) and the Program­mable Gain Amplifier (PGA). The gain and gain range
of the Programmable Gain Amplifier can be digitally
programmed. The combination of these two program­mable elements results in a variable gain ranging from
0dB up to a maximum gain as defined by the user
through external connections. The output of the VGA
can be used in either a single-ended or differential mode
to drive high performance analog-to-digital converters.

The VCA2612 also features low crosstalk and outstand­ing distortion performance. The combination of low
noise, and gain range programmability make the
VCA2612 a versatile building block in a number of
applications where noise performance is critical. The
VCA2612 is available in a TQFP-48 package.

2

®

VCA2612

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.

SPECIFICATIONS

At TA = +25°C, V

DD

= 5V, load resistance = 500Ω on each output to ground, MGS = 011, LNP = 22dB and fIN = 5MHz, unless otherwise noted. The input to the

preamp (LNP) is single-ended, and the output from the VCA is single-ended unless otherwise noted.

VCA2612Y

PARAMETER CONDITIONS MIN TYP MAX UNITS
PREAMPLIFIER

Input Resistance 600 kΩ
Input Capacitance 15 pF
Input Bias Current 1nA
CMRR f = 1MHz, VCA

CNTL

= 0.2V 50 dB

Maximum Input Voltage Preamp Gain = +5dB 1 Vp-p

Preamp Gain = +25dB 112 mVp-p

Input Voltage Noise

(1)

Preamp Gain = +5dB 3.5 nV/√Hz

Preamp Gain = +25dB 1.25 nV/√Hz
Input Current Noise Independent of Gain 350 fA/√Hz
Noise Figure, R

S

= 75Ω, RIN = 75Ω

(1)

RF = 550Ω, PreAmp Gain = 22dB, 6.2 dB

PGA Gain = 39dB

Bandwidth Gain = 22dB 80 MHz

PROGRAMMABLE VARIABLE GAIN AMPLIFIER

Peak Input Voltage Differential 2 Vp-p
–3dB Bandwidth 40 MHz
Slew Rate 300 V/µs
Output Signal Range R

L

≥ 500Ω Each Side to Ground 2.5 ±1V
Output Impedance f = 5MHz 1 Ω
Output Short-Circuit Current ±40 mA
Third Harmonic Distortion f = 5MHz, V

OUT

= 1Vp-p, VCA

CNTL

= 3.0V –45 –71 dBc

Second Harmonic Distortion f = 5MHz, V

OUT

= 1Vp-p, VCA

CNTL

= 3.0V –45 –63 dBc

IMD, Two-Tone V

OUT

= 2Vp-p, f = 1MHz –80 dBc

V

OUT

= 2Vp-p, f = 10MHz –80 dBc
1dB Compression Point f = 5MHz, Output Referred, Differential 6 Vp-p
Crosstalk

V

OUT

= 1Vp-p, f = 1MHz, Max Gain Both Channels

68 dB

Group Delay Variation 1MHz < f < 10MHz, Full Gain Range ±2ns

ACCURACY

Gain Slope 10.9 dB/V
Gain Error ±1

(2)

dB

Output Offset Voltage ±50 mV

GAIN CONTROL INTERFACE

Input Voltage (VCA

CNTL

) Range 0 to 3.0 V
Input Resistance 1MΩ
Response Time 45dB Gain Change, MGS = 111 0.2 µs

POWER SUPPLY

Specified Operating Range 4.75 5.0 5.25 V
Power Dissipation Operating, Both Channels 410 475 mW

NOTE: (1) For preamp driving VGA. (2) Referenced to best fit dB-linear curve.

3

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VCA2612

ELECTROSTATIC
DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.

ESD damage can range from subtle performance degrada­tion to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.

ABSOLUTE MAXIMUM RATINGS

Power Supply (+VS) ............................................................................. +6V

Analog Input ............................................................. –0.3V to (+V

S

+ 0.3V)

Logic Input ............................................................... –0.3V to (+V

S

+ 0.3V)

Case Temperature ......................................................................... +100°C

Junction Temperature .................................................................... +150°C

Storage Temperature...................................................... –40°C to +150°C

PACKAGE SPECIFIED
DRAWING TEMPERATURE PACKAGE ORDERING TRANSPORT

PRODUCT PACKAGE NUMBER RANGE MARKING NUMBER

(1)

MEDIA

VCA2612Y TQFP-48 Surface Mount 355 –40°C to +85°C A12 VCA2612Y/250 Tape and Reel

"""""VCA2612Y/2K "

NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K indicates 2000 devices per reel). Ordering 2000 pieces
of “VCA2612Y/2K” will get a single 2000-piece Tape and Reel.

PACKAGE/ORDERING INFORMATION

4

®

VCA2612

PIN CONFIGURATION

1V

DD

A Channel A +Supply
2 NC Do Not Connect
3 NC Do Not Connect
4 VCA

IN

NA Channel A VCA Negative Input

5 VCA

IN

PA Channel A VCA Positive Input

6 LNP

OUT

NA Channel A LNP Negative Output

7 LNP

OUT

PA Channel A LNP Positive Output
8 SWFBA Channel A Switched Feedback Output
9 FBA Channel A Feedback Output

10 COMP1A Channel A Frequency Compensation 1
11 COMP2A Channel A Frequency Compensation 2
12 LNP

IN

NA Channel A LNP Inverting Input

13 LNP

GS3

A Channel A LNP Gain Strap 3

14 LNP

GS2

A Channel A LNP Gain Strap 2

15 LNP

GS1

A Channel A LNP Gain Strap 1

16 LNP

IN

PA Channel A LNP Noninverting Input

17 V

DD

R +Supply for Internal Reference

18 V

BIAS

0.01µF Bypass to Ground

19 V

CM

0.01µF Bypass to Ground
20 GNDR Ground for Internal Reference
21 LNP

IN

PB Channel B LNP Noninverting Input

22 LNP

GS1

B Channel B LNP Gain Strap 1

23 LNP

GS2

B Channel B LNP Gain Strap 2

24 LNP

GS3

B Channel B LNP Gain Strap 3

25 LNP

IN

NB Channel B LNP Inverting Input
26 COMP2B Channel B Frequency Compensation 2
27 COMP1B Channel B Frequency Compensation 1
28 FBB Channel B Feedback Output
29 SWFBB Channel B Switched Feedback Output
30 LNP

OUT

PB Channel B LNP Positive Output

31 LNP

OUT

NB Channel B LNP Negative Output

32 VCA

IN

PB Channel B VCA Positive Input
33 VCA

IN

NB Channel B VCA Negative Input
34 NC Do Not Connect
35 NC Do Not Connect
36 V

DD

B Channel B +Analog Supply
37 GNDB Channel B Analog Ground
38 VCA

OUT

NB Channel B VCA Negative Output

39 VCA

OUT

PB Channel B VCA Positive Output

40 MGS

3

Maximum Gain Select 3 (LSB)

41 MGS

2

Maximum Gain Select 2

42 MGS

1

Maximum Gain Select 1 (MSB)

43 VCA

CNTL

VCA Control Voltage

44 VCA

IN

SEL VCA Input Select, HI = External
45 FBSW

CNTL

Feedback Switch Control: HI = ON,

46 VCA

OUT

PA Channel A VCA Positive Output

47 VCA

OUT

NA Channel A VCA Negative Output

48 GNDA Channel A Analog Ground

PIN

DESIGNATOR

DESCRIPTION PIN

DESIGNATOR

DESCRIPTION

PIN DESCRIPTIONS

36
35
34
33
32
31
30
29
28
27
26
25

VDDB
NC
NC
VCA

IN

NB

VCA

IN

PB

LNP

OUT

NB

LNP

OUT

PB
SWFBB
FBB
COMP1B
COMP2B
LNP

IN

NB

GNDA

VCA

OUT

NA

VCA

OUT

PA

FBSW

CNTL

VCA

IN

SEL

VCA

CNTL

MGS1MGS2MGS3VCA

OUT

PB

VCA

OUT

NB

GNDB

LNP

GS3

A

LNP

GS2

A

LNP

GS1

A

LNP

IN

PA

V

DD

R

V

BIAS

V

CM

GNDR

LNP

IN

PB

LNP

GS1

B

LNP

GS2

B

LNP

GS3

B

1
2
3
4
5
6
7
8

9
10
11
12

VDDA

NC
NC

VCA

IN

NA

VCA

IN

PA

LNP

OUT

NA

LNP

OUT

PA

SWFBA

FBA
COMP1A
COMP2A

LNP

IN

NA

48 47 46 45 44 43 42

41 40 39 38

13 14 15 16 17 18 19 20 21 22 233724

VCA2612

5

®

VCA2612

TYPICAL PERFORMANCE CURVES

At TA = +25°C, V

DD

= 5V, load resistance = 500Ω on each output to ground, MGS = 011, LNP = 22dB and fIN = 5MHz, unless otherwise noted. The input to the

preamp (LNP) is single-ended, and the output from the VCA is single-ended unless otherwise noted.

GAIN vs VCA

CNTL

VCA

CNTL

(V)

0.2 1.21.00.4 0.6 0.8 1.8 2.0 2.21.61.4 2.4 2.6 2.8 3.0

Gain (dB)

65
60
55
50
45
40
35
30
25
20
15

MGS = 111

MGS = 110

MGS = 101

MGS = 100

MGS = 011

MGS = 010

MGS = 001

MGS = 000

GAIN ERROR vs TEMPERATURE

VCA

CNTL

(V)

0.2 1.0 1.20.80.4 0.6 2.0 2.21.4 1.6 1.8 2.4 2.6 2.8 3.0

Gain Error (dB)

2.0

1.5

1.0

0.5
0

–0.5
–1.0
–1.5
–2.0

+25°C

–40°C

+85°C

GAIN ERROR vs VCA

CNTL

VCA

CNTL

(V)

0.2 1.0 1.20.80.4 0.6 2.0 2.21.4 1.6 1.8 2.4 2.6 2.8 3.0

Gain Error (dB)

2.0

1.5

1.0

0.5
0

–0.5
–1.0
–1.5
–2.0

10MHz

1MHz

5MHz

GAIN ERROR vs VCA

CNTL

VCA

CNTL

(V)

0.2 1.0 1.20.80.4 0.6 2.0 2.21.4 1.6 1.8 2.4 2.6 2.8 3.0

Gain Error (dB)

2.0

1.5

1.0

0.5
0

–0.5
–1.0
–1.5
–2.0

MGS = 011

MGS = 000

MGS = 111

GAIN MATCH: CHA to CHB = 0.2V

Delta Gain (dB)

–0.5 –0.4 –0.3 –0.2 –0.1 0.0 0.1 0.2 0.3 0.4 0.5

Units

100

90
80
70
60
50
40
30
20
10

0

GAIN MATCH: CHA to CHB = 3.0V

Delta Gain (dB)

–0.5 –0.4 –0.3 –0.2 –0.1 0.0 0.1 0.2 0.3 0.4 0.5

Units

100

90
80
70
60
50
40
30
20
10

0

6

®

VCA2612

TYPICAL PERFORMANCE CURVES (Cont.)

At TA = +25°C, V

DD

= 5V, load resistance = 500Ω on each output to ground, MGS = 011, LNP = 22dB and fIN = 5MHz, unless otherwise noted. The input to the

preamp (LNP) is single-ended, and the output from the VCA is single-ended unless otherwise noted.

GAIN vs FREQUENCY

(Pre-Amp)

Frequency (MHz)

0.1 1 10 100

Gain (dB)

30

25

20

15

10

5

0

LNP = 25dB

LNP = 22dB

LNP = 17dB

LNP = 5dB

GAIN vs FREQUENCY

(VCA and PGA, VCA

CNTL

= 0.2V)

Frequency (MHz)

0.1 1 10 100

Gain (dB)

5.0

4.0

3.0

2.0

1.0

0.0
–1.0
–2.0
–3.0
–4.0
–5.0

MGS = 111
MGS = 100
MGS = 011
MGS = 000

GAIN vs FREQUENCY

(VCA and PGA, VCA

CNTL

= 3.0V)

Frequency (MHz)

0.1 1 10 100

Gain (dB)

45
40
35
30
25
20
15
10

5
0

MGS = 111

MGS = 100

MGS = 011

MGS = 000

GAIN vs FREQUENCY

(VCA

CNTL

= 3.0V)

Frequency (MHz)

0.1 1 10 100

Gain (dB)

60

50

40

30

20

10

0

LNP = 25dB

LNP = 22dB

LNP = 5dB

LNP = 17dB

GAIN vs FREQUENCY

(LNP = 22dB)

Frequency (MHz)

0.1 1 10 100

Gain (dB)

60

50

40

30

20

10

0

VCA

CNTL

= 3.0V

VCA

CNTL

= 1.6V

VCA

CNTL

= 0.2V

OUTPUT REFERRED NOISE vs VCA

CNTL

VCA

CNTL

(V)

0 1.0 1.20.4 0.6 0.8 1.8 2.01.4 1.6 2.2 2.4 2.6 2.8 3.0

Noise (nv/√Hz)

1800
1600
1400
1200
1000

800
600
400
200

0

RS= 50Ω

MGS = 111

MGS = 011