BB VCA2619YT

VCA2619
SBOS276A − AUGUST 2003 − REVISED AUGUST 2003
Dual, Variable Gain Amplifier
with Input Buffer
FEATURES
DESCRIPTION
D GAIN RANGE: 50dB
D LOW CROSSTALK: -60dB at Max Gain,
The VCA2619 is a highly integrated, dual receive channel,
Variable Gain Amplifier (VGA) with analog gain control.
fIN = 5MHz
D HIGH−SPEED VARIABLE GAIN ADJUST
D POWER SHUTDOWN MODE
D HIGH IMPEDANCE INPUT BUFFER
APPLICATIONS
D
D
D
D
ULTRASOUND SYSTEMS
WIRELESS RECEIVERS
TEST EQUIPMENT
RADAR
The VCA2619s VGA section consists of two parts: the
Voltage Controlled Attenuator (VCA) and the Programmable
Gain Amplifier (PGA). The gain and gain range of the PGA
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 single−ended unity gain
input buffer provides predictable high input impedance. The
output of the VGA can be used in either a single−ended or
differential mode to drive high−performance Analog−to−
Digital (A/D) converters. A separate power−down pin
reduces power consumption.
The VCA2619 also features low crosstalk and outstanding
distortion performance. The combination of low noise and
gain range programmability make the VCA2619 a versatile
building block in a number of applications where noise
performance is critical. The VCA2619 is available in a
TQFP−32 package.
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.
All trademarks are the property of their respective owners.
Copyright  2003, Texas Instruments Incorporated
! ! www.ti.com
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SBOS276A − AUGUST 2003 − REVISED AUGUST 2003
ABSOLUTE MAXIMUM RATINGS(1)
Power Supply (+VS)
+6V
Analog Input
−0.3V to (+VS + 0.3V)
Logic Input
−0.3V to (+VS + 0.3V)
Case Temperature
+100°C
Junction Temperature
+150°C
Storage Temperature
−40°C to +150°C
(1) Stresses above those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. Exposure to
absolute maximum conditions for extended periods may affect
device reliability.
This integrated circuit can be damaged by ESD.
Texas Instruments 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.
PACKAGE/ORDERING INFORMATION
PRODUCT
PACKAGE-LEAD
PACKAGE
DESIGNATOR(1)
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
MARKING
VCA2619Y
TQFP−32
PBS
−40°C to +85°C
VCA2619Y
ORDERING NUMBER
(1) For the most current specification and package information, refer to our web site at www.ti.com.
2
TRANSPORT MEDIA,
QUANTITY
VCA2619YT
Tape and Reel, 250
VCA2619YR
Tape and Reel, 2000
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ELECTRICAL CHARACTERISTICS
At TA = +25°C, VDD = 5V, load resistance = 500Ω on each output to ground single−ended output (1Vpp), MGS = 111, VCACNTL = 2.9V and
fIN = 5MHz, unless otherwise noted.
VCA2619
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNIT
BUFFER
Input Resistance
600
kΩ
Input Capacitance
5
pF
Input Bias Current
1
nA
1
5.9
350
13
100
Vpp
nV/√Hz
fA/√Hz
dB
MHz
Maximum Input Voltage
Input Voltage Noise
Input Current Noise
Noise Figure
Bandwidth
PGA Gain = 45dB, RS = 50Ω
Independent of Gain
RF = 550Ω, PGA Gain = 45dB, RS = 75Ω
PROGRAMMABLE VARIABLE GAIN AMPLIFIER
Peak Input Voltage
1
Vpp
−3dB Bandwidth
20
MHz
300
V/µs
Slew Rate
Output Signal Range
RL ≥ 500Ω Each Side to Ground
Output Impedance
2nd-Harmonic Distortion
VOUT = 1Vpp, VCACNTL = 2.9V
VOUT = 1Vpp, VCACNTL = 2.9V
2nd-Harmonic Distortion
Differential, VOUT = 2Vpp, VCACNTL = 3.0V, MGS = 011
Overload Performance (2nd-Harmonic Distortion)
Input Signal = 0.5Vpp, VCACNTL = 2V
Crosstalk
Ω
±40
mA
−60
dBc
−42
−50
dBc
−50
dBc
−40 to −45
dB
Time Delay
IMD, 2−Tone
V
1
−45
Output Short−Circuit Current
3rd-Harmonic Distortion
2.5 ±1
VOUT = 2Vpp, f = 9.95MHz
2Vpp Differential
5
ns
−59
dBc
−60
dB
20
±2.75
±1.50
±50
52
50
dB/V
dB
dB
mV
dB
dB
ACCURACY
Gain Slope
Gain Error(1)
Output Offset Voltage
Gain Range
VCACNTL = 0.4V to 2.9V
VCACNTL = 0.2V to 3.0V
VCACNTL = 0.4V to 2.9V
VCACNTL = 0.2V to 3.0V
VCACNTL = 0.4V to 2.9V
48
±2.0
GAIN CONTROL INTERFACE
Input Voltage (VCACNTL) Range
Input Resistance
Response Time
45dB Gain Change
0 to 3.0
V
1
0.2
MΩ
µs
POWER SUPPLY
Specified Operating Range
Power Dissipation
Power−Down
4.75
5.0
240
9.2
5.25
300
V
mW
mW
(1) Referenced to best fit dB−linear curve.
3
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NC
NC
CP2A
CP1A
VDDA
GNDA
POUTA
NOUTA
32
31
30
29
28
27
26
25
PIN CONFIGURATION
+INA
1
24
VCACNTL
NC
2
23
MGS3
VDDR
3
22
MGS2
VBIAS
4
21
MGS1
VCM
5
20
PD
GNDR
6
19
NC
NC
7
18
NC
+INB
8
17
DNC
9
10
11
12
13
14
15
16
NC
NC
CP2B
CP1B
VDDB
GNDB
POUTB
NOUTB
VCA2619
PIN CONFIGURATION
4
PIN
DESIGNATOR
1
Noninverting Input Channel A
17
DNC
Do Not Connect
2
+INA
NC
DESCRIPTION
PIN
DESIGNATOR
DESCRIPTION
No Internal Connection
18
NC
No Internal Connection
3
VDDR
Internal Reference Supply
19
NC
No Internal Connection
4
VBIAS
Bias Voltage
20
PD
Power-Down (Active LOW)
5
VCM
Common−Mode Voltage
23
MGS1
Maximum Gain Select 1 (MSB)
6
GNDR
Internal Reference Ground
22
MGS2
Maximum Gain Select 2
7
NC
No Internal Connection
23
MGS3
Maximum Gain Select 3 (LSB)
8
+INB
Noninverting Input Channel B
24
VCACNTL
VCA Analog Control
9
NC
No Internal Connection
25
NOUTA
Negative VCA Output Channel A
10
NC
No Internal Connection
26
POUTA
Positive VCA Output Channel A
11
CP2B
Coupling Capacitor Channel B
27
GNDA
Ground Channel A
12
CP1B
Coupling Capacitor Channel B
28
VDDA
+5V Supply Channel A
13
VDDB
+5V Supply Channel B
29
CP1A
Coupling Capacitor Channel A
14
GNDB
Ground Channel B
30
CP2A
Coupling Capacitor Channel A
15
POUTB
Positive Output Channel B
31
NC
No Internal Connection
16
NOUTB
Negative Output Channel B
32
NC
No Internal Connection
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SBOS276A − AUGUST 2003 − REVISED AUGUST 2003
TYPICAL CHARACTERISTICS
At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless
otherwise noted.
GAIN ERROR vs TEMPERATURE
3.0
MGS = 111
2.5
MGS = 110
2.0
MGS = 101
+85_C
1.5
MGS = 010
MGS = 011
Gain Error (dB)
Gain (dB)
GAIN vs VCA
46
42
38
34
30
26
22
18
14
10
6
2
−2
−6
−10
−14
MGS = 100
+25_ C
1.0
0.5
0
−0.5
−1.0
−1.5
−2.0
−40_C
−2.5
−3.0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8
0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9
VCACNTL (V)
VCACNTL (V)
GAIN ERROR vs VCACNTL
GAIN ERROR vs VCACNTL
3.0
3.0
2.5
2.5
2.0
2.0
10MHz
0
−0.5
−1.0
5MHz
1MHz
−1.5
1.0
0.5
MGS = 100
0
−0.5
−1.0
MGS = 111
−1.5
−2.0
−2.0
−2.5
−2.5
−3.0
−3.0
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8
0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9
0.4
0.8
0.7
1.0
0.9
1.2
1.1
1.4
1.3
1.6
1.5
1.8
1.7
2.0
1.9
2.2
2.1
2.4
2.3
2.6
2.5
2.8
2.7
2.9
VCACNTL (V)
GAIN MATCH: CHA to CHB, VCAC NTL = 0.4V
GAIN MATCH: CHA to CHB, VCAC NT L = 2.9V
45
40
40
35
35
30
30
25
25
Units
45
20
0.6
0.5
VCACNTL (V)
20
15
10
10
5
5
0
0
−0.16
−0.14
−0.13
−0.11
−0.09
−0.08
−0.06
−0.04
−0.03
−0.01
0.01
0.02
0.04
0.06
0.07
0.09
0.11
0.12
0.14
More
15
−0.99
−0.91
−0.83
−0.75
−0.67
−0.59
−0.51
−0.42
−0.34
−0.26
−0.18
−0.10
−0.02
0.06
0.14
0.22
0.30
0.38
0.47
More
Units
MGS = 010
1.5
1.0
0.5
Gain Error (dB)
Gain Error (dB)
1.5
Delta Gain (dB)
Delta Gain (dB)
5
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TYPICAL CHARACTERISTICS (continued)
At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless
otherwise noted.
GAIN vs FREQUENCY
(VCACNTL = 2.9V)
GAIN vs FREQUENCY
(MGS = 111)
50
50
VCACNTL = 2.9V
MGS = 111
45
40
MGS = 100
40
30
30
Gain (dB)
Gain (dB)
35
25
20
20
15
0
MGS = 010
10
VCACNTL = 1.9V
10
VCACNTL = 0.9V
−10
5
0
100k
1M
10M
−20
100k
100M
1M
Frequency (MHz)
RS= 50Ω
900
MGS = 111
Noise (nV/√Hz)
Noise (nV/√Hz)
800
700
600
500
MGS = 100
400
300
200
100
0
RS = 50Ω
MGS = 111
MGS = 100
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
VCACNTL (V)
VCACNTL (V)
NOISE FIGURE vs RS
INPUT REFERRED NOISE vs RS
Noise Figure (dB)
Noise (nV√Hz)
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
100
10
1
1
10
100
RS (Ω )
6
100M
INPUT REFERRED NOISE vs VCACNTL
OUTPUT REFERRED NOISE vs VCACNTL
1100
1000
10M
Frequency (MHz)
1k
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
10
100
RS (Ω)
1k
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TYPICAL CHARACTERISTICS (continued)
NOISE FIGURE vs VCACNTL
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
−30
−35
Harmonic Distortion (dBc)
Noise Figure (dB)
At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless
otherwise noted.
−40
HARMONIC DISTORTION vs FREQUENCY
(Differential, 2VPP, MGS = 010)
VCA CN TL = 0.9V, H2
VCA CN TL = 0.9V, H3
VCA CN TL = 2.9V, H2
VCA CN TL = 2.9V, H3
−45
−50
−55
−60
−65
−70
100k
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
VCACNTL (V)
1M
10M
Frequency (Hz)
−30
−35
−40
−35
−45
−50
−55
−60
−65
−70
−75
VCA CN T L = 0.9V, H2
−80
−85
VCA CN T L = 0.9V, H3
VCA CN T L = 2.9V, H2
VCA CN T L = 2.9V, H3
−90
100k
1M
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
−30
HARMONIC DISTORTION vs FREQUENCY
(Differential, 2VPP, MGS = 100)
−40
−55
−60
−65
−70
−30
−35
−55
−60
−65
−70
VCA CN TL = 0.9V, H2
VCA CN TL = 0.9V, H3
VCA CN TL = 2.9V, H2
VCA CN TL = 2.9V, H3
Frequency (Hz)
10M
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
−50
1M
1M
10M
Frequency (Hz)
−40
−45
−85
−90
100k
0.9V, H2
0.9V, H3
2.9V, H2
2.9V, H3
−50
−80
100k
10M
−35
−80
=
=
=
=
−75
HARMONIC DISTORTION vs FREQUENCY
(Single−Ended, 1VPP, MGS = 010)
−75
VCA C NTL
VCA C NTL
VCA C NTL
VCA C NTL
−45
Frequency (Hz)
−30
HARMONIC DISTORTION vs FREQUENCY
(Differential, 2VPP, MGS = 111)
HARMONIC DISTORTION vs FREQUENCY
(Single−Ended, 1VPP, MGS = 100)
−40
−45
−50
−55
−60
−65
−70
−75
VCA CN TL = 0.9V, H2
−80
VCA CN TL = 0.9V, H3
VCA CN TL = 2.9V, H2
VCA CN TL = 2.9V, H3
−85
−90
100k
1M
10M
Frequency (Hz)
7
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TYPICAL CHARACTERISTICS (continued)
At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless
otherwise noted.
HARMONIC DISTORTION vs FREQUENCY
(Single−Ended, 1VPP, MGS = 111)
−30
−35
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
−40
−45
−50
−55
−60
−65
−70
−75
−80
VCA C NTL = 0.9V, H2
VCA C NTL = 0.9V, H3
VCA C NTL = 2.9V, H2
VCA C NTL = 2.9V, H3
−85
−90
100k
1M
MGS = 010, H2
MGS = 100, H2
MGS = 111, H2
MGS = 010, H3
MGS = 100, H3
MGS = 111, H3
0.9
10M
1.5
1.7
1.9
2.1
2.3
2.5
INTERMODULATION DISTORTION
(Single−Ended, 1VPP , f IN = 10MHz)
MGS = 010,
MGS = 100,
MGS = 111,
MGS = 010,
MGS = 100,
MGS = 111,
−40
2.7
2.9
0
H2
H2
H2
H3
H3
H3
−10
−20
−45
−50
−55
−30
−40
−50
−60
−70
−80
−90
−65
−100
0.9
1.1
1.3
1.5
1.7
1.9
2.1
2.3
2.5
2.7
2.9
9.5
VCACNTL (V)
9.6
9.7
9.8
9.9 10.0 10.1 10.2 10.3 10.4 10.5
Frequency (MHz)
CROSS TALK vs FREQUENCY
(Differential, 2VPP, MGS = 011)
INTERMODULATION DISTORTION
(Differential, 2 VPP, fIN = 10MHz)
0
0
−10
−10
−20
−30
Cross Talk (dB)
Amplitude (dB)
1.3
HARMONIC DISTORTION vs VCACNTL
(Single−Ended, 1VPP, 5MHz)
−60
−40
−50
−60
−70
−80
VCACNTL = 0.9V
−20
−30
−40
VCACNTL = 1.9V
−50
−60
−90
VCACNTL = 2.9V
−70
−100
9.5
8
1.1
VCACNTL (V)
−35
Harmonic Distortion (dBc)
0
−5
−10
−15
−20
−25
−30
−35
−40
−45
−50
−55
−60
−65
−70
−75
−80
Frequency (Hz)
Amplitude (dB)
−30
HARMONIC DISTORTION vs VCACNTL
(Differential, 2VPP, 5MHz)
9.6
9.7
9.8
9.9 10.0 10.1 10.2 10.3 10.4 10.5
Frequency (MHz)
1M
10M
Frequency (Hz)
20M
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SBOS276A − AUGUST 2003 − REVISED AUGUST 2003
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless
otherwise noted.
OVERLOAD DISTORTION vs FREQUENCY
55
0.2V
0.3V
0.5V
1V
−10
ICC (CHA and CHB) vs TEMPERATURE
54
53
52
−20
ICC (mA)
2nd−Harmonic Distortion (dBc)
0
−30
−40
51
50
49
48
47
−50
46
−60
45
1M
10M
−40 −30 −20 −10
0
10
20
30
40
50
60
70
80
90
Temperature (_C)
Frequency (Hz)
OVERVIEW
The VCA2619 is a dual-channel, VGA consisting of three
primary blocks: an Input Buffer, a VCA, and a PGA. All
stages are ac coupled, with the coupling into the PGA
stage being made variable by placing an external capacitor between the CP1 and CP2 pins. This will be discussed
further in the PGA section. By using the internal coupling
into the PGA, the result is a high-pass filter characteristic
with cutoff at approximately 75kHz. The output PGA naturally rolls off at around 30MHz, making the usable bandwidth of the VCA2619 between 75kHz and 30MHz.
Channel A
Input
Buffer
Analog
Control
VCA
Control
Channel B
Input
VCA
Buffer
VCA
PGA
Channel A
Output
Maximum
Gain
Select
MGS
PGA
Channel B
Output
INPUT BUFFER
The input buffer is a unity gain amplifier (gain of +1) with
a bandwidth of 100MHz with an input resistance of approximately 600kΩ. The input buffer isolates the circuit driving
the VCA2619 inputs from the internal VCA block, which
would present a varying impedance to the input circuitry.
To allow symmetrical operation of the input buffer, the input
to the buffer must be ac coupled through an external capacitor. The recommended value of the capacitor is
0.01µF. It should be noted that if the capacitor value were
increased, the power-on time of the VCA2619 would be increased. If a decrease in the power-on time is needed, the
value can be decreased to no less than 100pF.
Figure 1. Simplified Block Diagram of the
VCA2619.
9
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VOLTAGE-CONTROLLED ATTENUATOR
The MGS bits adjust the overall range of attenuation and
maximum gain while the VCACNTL voltage adjusts the
actual attenuation factor. Figure 3 is a simplified version of
the voltage control attenuator. Figure 4 illustrates the
piecewise approximation to the logarithmic control
characteristics. At any given maximum gain setting, the
analog variable gain characteristic is linear in dB as a
function of the control voltage, and is created as a
piecewise approximation of an ideal dB-linear transfer
function. The VCA control circuitry is common to both
channels of the VCA2619. The range for the VCACNTL
input spans from 0V to 3V. Although overdriving the
VCA CNTL input above the recommended 3V maximum will
not damage the part, this condition should be avoided.
The magnitude of the VCA input signal from the input
buffer is reduced by a programmable attenuation factor,
set by the analog VCA Control Voltage (VCACNTL) at pin
24. The maximum attenuation is programmable by using
the three MGS bits (pins 21, 22, and 23). Figure 2
illustrates this dual-adjust characteristic.
VCA Attenuation (dB)
0
Minimum Attenuation
−41
Maximum Attenuation
−52.3
0
3.0V
Control Voltage
Figure 2. Swept Attenuator Characteristic.
RS
Input
Output
Q1A
Q1B
Q2A
Q2B
Q3A
Q3B
Q4A
Q4B
Q5A
VCM
A1
A2
A3
A4
B1
B2
Figure 3. Simplified Attenuator Diagram.
10
A5
Q5B
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Attenuator
Input
RS
A1 to A10 Attenuator Stages
Attenuator
Output
QS
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Q9
Q10
VCM
A1
A2
A3
C1
A4
C2
V1
A5
C3
V2
V3
A6
C4
V4
C5
A8
C6
V5
Control
Input
A7
A9
C7
V6
A10
C8
V7
C9
V8
C10
V9
V10
C1 to C10 Clipping Amplifiers
0dB
−5.2dB
Attenuation Characteristic of Individual FETs
VCM − VT
0
V1
V2
V3
V4
V5
V6
V7
V8
V9
V10
Characteristic of Attenuator Control Stage Output
OVERALL CONTROL CHARACTERISTICS OF ATTENUATOR
0dB
−52.3dB
0.2V
Control Signal
3V
Figure 4. Piecewise Approximation to Logarithmic Control Characteristics.
11
"
#$%&
www.ti.com
SBOS276A − AUGUST 2003 − REVISED AUGUST 2003
Table 1. MGS Settings.
PGA POST-AMPLIFIER
Figure 5 shows a simplified circuit diagram of the PGA
block. As stated before, the input to the PGA is ac coupled
with an internal capacitor. Provisions are made so that an
external capacitor can be placed in parallel with the internal capacitor, thus lowering the usable low-frequency
bandwidth. The low-frequency bandwidth is set by the following equation:
1
(2 @ p @ 500kW @ (220pF ) C EXTERNAL))
MGS
SETTING
ATTENUATOR GAIN
VCACNTL = 0.2V TO 3V
ATTENUATOR +
DIFFERENTIAL PGA
GAIN
000
Not Valid
Not Valid
001
Not Valid
Not Valid
010
−41.0dB to 0dB
−12dB to 29dB
−11.5dB to 31.8dB
(1)
011
−43.3dB to 0dB
100
−46.4dB to 0dB
−11.5dB to 34.9dB
101
−48.2dB to 0dB
−10.6dB to 37.6dB
110
−50.2dB to 0dB
−9.8dB to 40.4dB
111
−52.3dB to 0dB
−9.3dB to 43.3dB
where CEXTERNAL is the external capacitor value in farads.
The PGA architecture converts the single−ended signal
from the VCA into a differential signal. Low input noise was
also a requirement of the PGA design due to the large
amount of signal attenuation that can be asserted before
the PGA. At minimum VCA attenuation (used for small input signals), the input buffer noise dominates; at maximum
VCA attenuation (large input signals), the PGA noise dominates. Note that if the PGA output is single−ended, the apparent gain will be 6dB lower.
Care should be taken to avoid using too large a value of
capacitor, as this can increase the power-on delay time.
The PGA gain is programmed with the same MGS bits that
control the VCA maximum attenuation factor. For VCACNTL = 3V (no attenuation), the VCA + PGA gain will be
controlled by the programmed PGA gain (29dB to 43dB in
approximately 3dB steps). For clarity, the gain and attenuation factors are detailed in Table I.
VDD
To Bias
Circuitry
Q1
RL
VCAOUTP
Q11
Q12
Q3
VCM
Q9
RL
VCAOUTN
Q8
RS1
VCM
Q13
RS2
+In
Q4
Q7
Q14
Q2
Q5
Q10
Q6
To Bias
Circuitry
Figure 5. Simplified Block Diagram of PGA.
12
−In
"
#$%&
www.ti.com
SBOS276A − AUGUST 2003 − REVISED AUGUST 2003
LAYOUT CONSIDERATIONS
Adequate power−supply decoupling must be used in order
to achieve the best possible performance. Decoupling capacitors on the VCACNTL voltage should also be used to
help minimize noise. Recommended values can be obtained from the layout diagram of Figure 6.
The VCA2619 is an analog amplifier capable of high gain.
When working on a PCB layout for the VCA2619, it is recommended to utilize a solid ground plane that is connected
to analog ground. This helps to maximize the noise performance of the VCA2619.
+5V
0.1µF
1µF
+5V
0.01µF
INA
1
0.1µF
0.1µF
1µF
1µF
INA
28 3
5
VDDA VDDR VCM
−OUTA
+OUTA
25
26
0.01µF
−OUTA
0.01µF
+OUTA
VCA2619
−OUTB
0.01µF
INB
8
INB
+OUTB
16
15
0.01µF
−OUTB
0.01µF
+OUTB
VDDB VBIAS VCNTL
13
4
24
1µF
0.1µF
0.1µF
+5V
1µF
0.1µF
VCACNTL
Figure 6. VCA2619 Layout.
13
PACKAGE OPTION ADDENDUM
www.ti.com
9-Dec-2004
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
VCA2619YR
ACTIVE
TQFP
PBS
32
2000
None
Call TI
Call TI
VCA2619YT
ACTIVE
TQFP
PBS
32
250
None
Call TI
Call TI
Lead/Ball Finish
MSL Peak Temp (3)
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional
product content details.
None: Not yet available Lead (Pb-Free).
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,
including bromine (Br) or antimony (Sb) above 0.1% of total product weight.
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
MECHANICAL DATA
MPQF027 – NOVEMBER 1995
PBS (S-PQFP-G32)
PLASTIC QUAD FLATPACK
0,23
0,17
0,50
24
0,08 M
17
25
16
32
9
0,13 NOM
1
8
3,50 TYP
Gage Plane
5,05
SQ
4,95
7,10
SQ
6,90
0,25
0,10 MIN
0°– 7°
0,70
0,40
1,05
0,95
Seating Plane
0,08
1,20 MAX
4087735/A 11/95
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
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1
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