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VCA820
SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
VCA820 Wideband, > 40-dB Adjust Range, Linear in dB
Variable Gain Amplifier
1 Features
•
•
•
•
•
•
•
1
150-MHz Small-Signal Bandwidth
137-MHz, 5-VPP Bandwidth (G = +10 V/V)
0.1-dB Gain Flatness to 28 MHz
1700-V/μs Slew Rate
> 40-dB Gain Adjust Range
High Gain Accuracy: 20 dB ±0.4dB
High Output Current: 160 mA
2 Applications
•
•
•
•
AGC Receivers With RSSI
Differential Line Receivers
Pulse Amplitude Compensation
Variable Attenuators
The VCA820 internal architecture consists of two
input buffers and an output current feedback amplifier
stage, integrated with a multiplier core to provide a
complete variable gain amplifier (VGA) system that
does not require external buffering. The maximum
gain is set externally with two resistors, providing
flexibility in designs. The maximum gain is intended
to be set between +2 V/V and +100 V/V. Operating
from ±5-V supplies, the gain control voltage for the
VCA820 adjusts the gain linearly in dB as the control
voltage varies from 0 V to +2 V. For example, set for
a maximum gain of +10 V/V, the VCA820 provides 20
dB, at +2-V input, to –20 dB at 0-V input of gain
control range. The VCA820 offers excellent gain
linearity. For a 20-dB maximum gain, and a gaincontrol input voltage varying between 1 V and 2 V,
the gain does not deviate by more than ±0.4dB
(maximum at +25°C).
Device Information(1)
3 Description
The VCA820 is a dc-coupled, wideband, linear in dB,
continuously
variable,
voltage-controlled
gain
amplifier. The VCA820 provides a differential input to
single-ended conversion with a high-impedance gain
control input, used to vary the gain down 40 dB from
the nominal maximum gain set by the gain resistor
(RG) and feedback resistor (RF).
PART NUMBER
VCA820
PACKAGE
BODY SIZE (NOM)
SOIC (14)
8.65 mm × 3.91 mm
VSSOP (10)
3.00 mm × 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
space
space
space
Wideband Differential to Single-Ended Amplifier
Common-Mode Rejection Ratio
1 kΩ
95
+VIN
RG+
RS
200Ω
FB
VCA820
RG-V IN
VIN-
20Ω
RS
Av = 20 dB
Common-Mode Rejection Ratio (dB)
VIN+
90
85
80
75
70
65
60
55
50
45
Input-Referred
40
100k
1M
10M
100M
Frequency (Hz)
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
VCA820
SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Device Options.......................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
3
4
7.1
7.2
7.3
7.4
7.5
7.6
7.7
Absolute Maximum Ratings ...................................... 4
ESD Ratings.............................................................. 4
Recommended Operating Conditions....................... 4
Thermal Information .................................................. 4
Electrical Characteristics: VS = ±5 V......................... 5
Typical Characteristics: VS = ±5 V, DC Parameters . 9
Typical Characteristics: VS = ±5 V, DC and PowerSupply Parameters .................................................. 10
7.8 Typical Characteristics: VS = ±5 V, AVMAX = 6 dB .. 11
7.9 Typical Characteristics: VS = ±5 V, AVMAX = 20 dB 15
7.10 Typical Characteristics: VS = ±5 V, AVMAX = 40
dB............................................................................. 19
8
Detailed Description ............................................ 23
8.2 Functional Block Diagram ....................................... 23
8.3 Feature Description................................................. 23
8.4 Device Functional Modes........................................ 24
9
Application and Implementation ........................ 27
9.1 Application Information............................................ 27
9.2 Typical Applications ................................................ 29
9.3 System Examples ................................................... 35
10 Power Supply Recommendations ..................... 37
11 Layout................................................................... 37
11.1 Layout Guidelines ................................................. 37
11.2 Layout Example .................................................... 38
11.3 Thermal Considerations ........................................ 38
12 Device and Documentation Support ................. 39
12.1
12.2
12.3
12.4
12.5
Device Support......................................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
39
39
39
39
39
13 Mechanical, Packaging, and Orderable
Information ........................................................... 39
8.1 Overview ................................................................. 23
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision C (October 2009) to Revision D
•
Page
Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation
section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and
Mechanical, Packaging, and Orderable Information section .................................................................................................. 1
Changes from Revision B (December 2008) to Revision C
Page
•
Deleted lead temperature specification from Absolute Maximum Ratings table ................................................................... 4
•
Changed Figure 13; corrected y-axis units from VIN (mV) to VOUT (mV) .............................................................................. 11
•
Changed Figure 14; corrected y-axis units from VIN (mV) to VOUT (V) ................................................................................. 11
•
Changed Figure 33; corrected y-axis units from VIN (mV) to VOUT (mV) .............................................................................. 15
•
Changed Figure 34; corrected y-axis units from VIN (mV) to VOUT (V) ................................................................................. 15
•
Changed Figure 54; corrected y-axis units from VIN (mV) to VOUT (mV) .............................................................................. 19
•
Changed Figure 55; corrected y-axis units from VIN (mV) to VOUT (V), corrected VIN value in graph .................................. 19
Changes from Revision A (August 2008) to Revision B
•
2
Page
Revised second paragraph of the Wideband Variable Gain Amplifier Operation section describing pin 9 ......................... 29
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
5 Device Options
Table 1. Wideband Variable Gain Amplifiers - VGAs
SINGLES
DUALS
GAIN ADJUST RANGE
(dB)
INPUT NOISE
(nV/√Hz)
SIGNAL BANDWIDTH (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
6 Pin Configuration and Functions
D Package
14-Pin SOIC
Top View
DGS Package
10-Pin VSSOP
Top View
V+
1
14 V+
VG
2
13 NC
+VIN
3
12 I-
+RG
4
11 GND
-RG
5
10 VOUT
-VIN
6
9
VREF
V-
7
8
V-
I-
1
10 GND
+V
2
9
VOUT
VG
3
8
-V
+VIN
4
7
-VIN
+RG
5
6
-RG
Pin Functions
PIN
NAME
I/O
DESCRIPTION
SOIC
VSSOP
GND
11
10
—
I–
12
1
I
Feedback Resistor Input
–RG
5
6
I
Gain Set Resistor
+RG
4
5
I
Gain Set Resistor
V–
7, 8
—
P
Negative Supply
V+
1, 14
—
P
Positive Supply
–V
—
8
P
Negative Supply
+V
—
2
P
Positive Supply
VG
2
3
I
Gain Control
–VIN
6
7
I
Inverting Input
+VIN
3
4
I
Noninverting Input
VOUT
10
9
O
Output
VREF
9
—
I
Output Voltage Reference
Ground
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
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7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
Power supply
Internal power dissipation
MAX
UNIT
±6.3
V
See Thermal Information
Input voltage
±VS
V
Junction temperature (TJ)
150
°C
140
°C
125
°C
Junction temperature (TJ), maximum continuous operation
Storage temperature
(1)
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
7.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2000
Charged device model (CDM), per JEDEC specification JESD22C101 (2)
±500
Machine model (MM)
±200
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
Operating voltage
Operating temperature
MIN
NOM
MAX
7
10
12
UNIT
V
–40
25
85
°C
7.4 Thermal Information
VCA820
THERMAL METRIC
(1)
D [SOIC]
DGS [VSSOP]
14 PINS
10 PINS
UNIT
80
130
°C/W
RθJA
Junction-to-ambient thermal resistance
RθJC(top)
Junction-to-case (top) thermal resistance
49.8
46.6
°C/W
RθJB
Junction-to-board thermal resistance
44.9
94.3
°C/W
ψJT
Junction-to-top characterization parameter
13.8
2.2
°C/W
ψJB
Junction-to-board characterization parameter
44.6
92.7
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
n/a
n/a
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
7.5 Electrical Characteristics: VS = ±5 V
At AVMAX = 20 dB, RF = 1 kΩ, RG = 200 Ω, and RL = 100 Ω, unless otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
TEST
LEVEL (1)
MHz
C
MHz
C
MHz
B
MHz
C
V/μs
B
ns
B
ns
C
dBc
B
dBc
B
C
AC PERFORMANCE
Small-signal bandwidth (SO-14
package)
Large-signal bandwidth
AVMAX = 6 dB, VO = 1
VPP, VG = +2 V
TJ = 25°C
168
AVMAX = 20 dB, VO = 1
VPP, VG = +2 V
TJ = 25°C
150
AVMAX = 40 dB, VO = 1
VPP, VG = +2 V
TJ = 25°C
118
AVMAX = 20 dB, VO = 5
VPP, VG = +2 V
TJ = 25°C
137
TJ = 25°C
Gain control bandwidth
VG = 1 VDC + 10 mVPP
TJ = 0°C to 70°C
170
(2)
TJ = –40°C to
85°C (2)
Bandwidth for 0.1dB flatness
AVMAX = 20 dB, VO = 1
VPP, VG = +2 V
Slew rate
AVMAX = 20 dB, VO = 5-V
step, VG = +2 V
170
165
TJ = 25°C
28
TJ = 25°C
1500
TJ = 0°C to 70°C (2)
1500
TJ = –40°C to
85°C (2)
1450
TJ = 25°C
Rise-and-fall time
Settling time to 0.01%
AVMAX = 20 dB, VO = 5-V
step, VG = +2 V
AVMAX = 20 dB, VO = 5-V
step, VG = +2 V
200
1700
2.5
3.1
TJ = 0°C to 70°C (2)
3.2
TJ = –40°C to
85°C (2)
3.2
TJ = 25°C
11
Harmonic distortion
2nd-harmonic
VO = 2 VPP, f = 20 MHz
TJ = 25°C
–60
TJ = 0°C to 70°C (2)
–60
TJ = –40°C to
85°C (2)
–60
TJ = 25°C
3rd-harmonic
VO = 2 VPP, f = 20 MHz
TJ = 0°C to 70°C
–66
(2)
TJ = –40°C to
85°C (2)
–62
–68
–66
–66
Input voltage noise
f > 100 kHz
TJ = 25°C
8.2
nV/√Hz
Input current noise
f > 100 kHz
TJ = 25°C
2.6
pA/√Hz
GAIN CONTROL
TJ = 25°C
Absolute gain error
AVMAX = 20 dB, VG = 2 V
TJ = 0°C to 70°C
±0.1
(2)
±0.5
TJ = –40°C to
85°C (2)
TJ = 25°C
0.85
VSLOPE
TJ = 25°C
0.09
TJ = 25°C
±0.3
(1)
(2)
AVMAX = 20 dB, VG = 1 V,
(G = 18.06 dB)
dB
A
V
C
V
C
dB
A
±0.6
VCTRL0
Absolute gain error
±0.4
±0.4
TJ = 0°C to 70°C (2)
±0.5
TJ = –40°C to
85°C (2)
±0.6
Test levels: (A) 100% tested at +25°C. Over temperature limits set by characterization and simulation. (B) Limits set by characterization
and simulation. (C) Typical value only for information.
Junction temperature = ambient at low temperature limit; junction temperature = ambient +23°C at high temperature limit for over
temperature specifications.
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Electrical Characteristics: VS = ±5 V (continued)
At AVMAX = 20 dB, RF = 1 kΩ, RG = 200 Ω, and RL = 100 Ω, unless otherwise noted.
PARAMETER
TEST CONDITIONS
TJ = 25°C
Gain at VG = 0.2V
Relative to maximum gain
Relative to maximum gain
Average gain control
bias current drift
Gain control input impedance
MAX
–26
–24
–24
TJ = –40°C to
85°C (2)
–23
–26
–24
TJ = –40°C to
85°C (2)
–23
10
16.6
TJ = –40°C to
85°C (2)
16.7
TJ = 0°C to 70°C (2)
±12
TJ = –40°C to
85°C (2)
±12
70 || 1
TJ = 25°C
±4
TEST
LEVEL (1)
dB
A
dB
A
μA
A
nA/°C
B
kΩ || pF
C
mV
A
μV/°C
B
μA
A
nA/°C
B
μA
A
nA/°C
B
mA
B
16
TJ = 0°C to 70°C (2)
TJ = 25°C
UNIT
–24
TJ = 0°C to 70°C (2)
TJ = 25°C
Gain control bias current
TYP
TJ = 0°C to 70°C (2)
TJ = 25°C
Gain at VG = 0.2V
MIN
DC PERFORMANCE
Input offset voltage
Average input offset
voltage drift
AVMAX = 20 dB, VCM = 0
V, VG = 1 V
AVMAX = 20 dB, VCM = 0
V, VG = 1 V
TJ = 0°C to 70°C (2)
TJ = –40°C to
85°C (2)
Input bias current
Average input bias
current drift
AVMAX = 20 dB, VCM = 0
V, VG = 1 V
30
TJ = –40°C to
85°C (2)
30
Input offset current
Average input offset
current drift
AVMAX = 20 dB, VCM = 0
V, VG = 1 V
6
25
29
TJ = –40°C to
85°C (2)
31
TJ = 0°C to 70°C (2)
90
TJ = –40°C to
85°C (2)
90
±0.5
±2.5
TJ = 0°C to 70°C (2)
±3.2
TJ = –40°C to
85°C (2)
±3.5
TJ = 0°C to 70°C (2)
±16
TJ = –40°C to
85°C (2)
±16
TJ = 25°C
Maximum current through gain
resistance
19
TJ = 0°C to 70°C (2)
TJ = 25°C
AVMAX = 20 dB, VCM = 0
V, VG = 1 V
±19
TJ = 0°C to 70°C (2)
TJ = 25°C
AVMAX = 20 dB, VCM = 0
V, VG = 1 V
±17
±17.8
TJ = 0°C to 70°C (2)
TJ = –40°C to
85°C (2)
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±2.6
±2.55
±2.55
±2.5
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Electrical Characteristics: VS = ±5 V (continued)
At AVMAX = 20 dB, RF = 1 kΩ, RG = 200 Ω, and RL = 100 Ω, unless otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
TJ = 25°C
+1.6
+1.6
TJ = 0°C to 70°C (2)
+1.6
TJ = –40°C to
85°C (2)
+1.6
MAX
UNIT
TEST
LEVEL (1)
V
A
V
A
dB
A
INPUT
Most positive common-mode
input voltage
RL = 100 Ω
TJ = 25°C
Most negative common-mode
input voltage
TJ = 0°C to 70°C
RL = 100 Ω
–2.1
(2)
–2.1
TJ = –40°C to
85°C (2)
–2.1
TJ = 25°C
Common-mode rejection ratio
TJ = 0°C to 70°C
VCM = ±0.5 V
–2.1
65
(2)
TJ = –40°C to
85°C (2)
80
60
60
Input impedance
Differential
TJ = 25°C
0.5 || 1
MΩ || pF
C
Common-mode
TJ = 25°C
0.5 || 2
MΩ || pF
C
V
A
V
A
mA
A
0.01
Ω
C
OUTPUT
TJ = 25°C
TJ = 0°C to 70°C (2)
RL = 1 kΩ
Output voltage swing
RL = 100 Ω
Output current
Output impedance
VO = 0 V, RL = 5 Ω
AVMAX = 20 dB, f > 100
kHz, VG = +2 V
±3.8
TJ = –40°C to
85°C (2)
±3.7
TJ = 25°C
±3.7
TJ = 0°C to 70°C (2)
±3.6
TJ = –40°C to
85°C (2)
±3.5
TJ = 25°C
±140
TJ = 0°C to 70°C (2)
±130
TJ = –40°C to
85°C (2)
±130
TJ = 25°C
±4.0
±3.75
±3.9
±160
POWER SUPPLY
Specified operating voltage
TJ = 25°C
±5
V
C
Minimum operating voltage
TJ = 25°C
±3.5
V
C
V
A
mA
A
mA
A
Maximum operating voltage
TJ = 25°C
±6
TJ = 0°C to 70°C (2)
±6
TJ = –40°C to
85°C (2)
±6
TJ = 25°C
Maximum quiescent current
VG = 1 V
34
TJ = 0°C to 70°C (2)
TJ = –40°C to
85°C (2)
TJ = 25°C
Minimum quiescent current
VG = 1 V
TJ = 0°C to 70°C (2)
TJ = –40°C to
85°C (2)
35
35.5
36
34
32.5
32
31.5
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Electrical Characteristics: VS = ±5 V (continued)
At AVMAX = 20 dB, RF = 1 kΩ, RG = 200 Ω, and RL = 100 Ω, unless otherwise noted.
PARAMETER
Power-supply rejection ratio
(–PSRR)
8
TEST CONDITIONS
MIN
TYP
TJ = 25°C
–61
–68
TJ = 0°C to 70°C (2)
–59
TJ = –40°C to
85°C (2)
–58
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MAX
UNIT
TEST
LEVEL (1)
dB
A
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7.6 Typical Characteristics: VS = ±5 V, DC Parameters
At TA = +25°C, RL = 100 Ω, VG = +1 V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
40
IRG MAX = 2.6mA
VIN MAX(VPP) = 2 ´ RG ´ IRG MAX (AP)
Maximum Gain Adjust Range (dB)
Differential Input Voltage (VPP)
10
1
0.1
100
25
VO = 1VPP
20
VO = 2VPP
15
VO = 4VPP
10
VO = 3VPP
5
1k
100
1k
10k
Gain Resistor (W)
Feedback Resistor (W)
Figure 1. Maximum Differential Input Voltage vs Gain
Resistor
Figure 2. Maximum Gain Adjust Range vs Feedback
Resistor
12
60
IRG = 2.6mA
AVMAX(V/V) = 2 ´ [RF/VIN(VPP)] ´ 2 ´ IRG (AP)
50
Absolute
Error
10
RF = 3kW
40
Absolute
Error
8
RF = 4kW
Gain (V/V)
Maximum Gain Adjust Range (dB)
30
0
10
RF = 5kW
30
RF = 500W
6
Relative Error to
Maximum Gain
4
20
RF = 1kW
10
RF = 1.5kW
2
RF = 2kW
0
0
0.1
1
10
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Output Voltage (VPP)
Control Voltage (V)
Figure 3. Maximum Gain Adjust Range vs Peak-to-Peak
Output Voltage
Figure 4. Gain Error Band vs Gain Control Voltage
1500
20
1400
Feedback Resistor (W)
40
0
Gain (V/V)
IRG = 2.6mA
AVMAX(V/V) = 2 ´ [RF/VIN(VPP)] ´ 2 ´ IRG (AP)
35
-20
Equation
A(V/V) = K ´
-40
RF
´
RG
1
( VV
G0
1+e
- VG
SLOPE
)
-60
Data
VCTRL0 = 0.85V
VSLOPE = 90mV
-80
1300
1200
1100
1000
900
NOTE: -3dB bandwidth will vary with the package.
See the Application section for more details.
800
700
-100
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
1
10
100
AVMAX (V/V)
Control Voltage (V)
Figure 5. Nominal Gain vs Calculated Gain
Figure 6. Recommended RF and RG vs AVMAX
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7.7 Typical Characteristics: VS = ±5 V, DC and Power-Supply Parameters
At TA = +25°C, RL = 100 Ω, VG = +1 V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
36
35
35
Quiescent Current (mA/div)
Quiescent Current (mA/div)
36
-IQ
34
+IQ
33
32
31
-IQ
34
33
32
+IQ
31
31
31
29
29
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Gain Control Voltage (V)
Figure 7. Supply Current vs Control Voltage (AVMAX = 6 dB)
Figure 8. Supply Current vs Control Voltage (AVMAX = 20 dB)
36
0
25
Input Offset Voltage (mV)
Quiescent Current (mA/div)
35
-IQ
34
33
32
+IQ
31
-0.5
-1.0
15
-1.5
10
Input Offset Voltage
5
-2.0
-2.5
31
0
Input Offset Current
29
-3.0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
-5
-50
-25
0
25
50
75
100
125
Temperature (°C)
Gain Control Voltage (V)
Figure 9. Supply Current vs Control Voltage (AVMAX = 40 dB)
10
20
Input Bias Current
Input Bias and Offset Current (mA)
VG = +1V
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Figure 10. Typical DC Drift vs Temperature
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
7.8 Typical Characteristics: VS = ±5 V, AVMAX = 6 dB
3
3
0
0
Normalized Gain (dB)
Normalized Gain (dB)
At TA = +25°C, RL = 100 Ω, RF = 1.33 kΩ, RG = 1.33 kΩ, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
-3
VG = +2V
-6
-9
-12
AVMAX = 6dB
VIN = 1VPP
RL = 100W
-15
-18
VO = 1VPP
-3
-6
VO = 2VPP
-9
VO = 5VPP
-12
VO = 7VPP
VG = +1V
-15
AVMAX = 6dB
-18
1M
10M
100M
1G
1M
10M
Frequency (Hz)
Figure 11. Small-Signal Frequency Response
2
100
1
VOUT (V)
200
VOUT (mV)
3
0
-100
0
-1
-2
VIN = 250mVPP
f = 20MHz
-300
VIN = 2.5VPP
f = 20MHz
-3
Time (10ns/div)
Time (10ns/div)
Figure 13. Small-Signal Pulse Response
0
0
-0.04
-dG, VG = +2V
-0.06
-dG, VG = +1V
-0.20
-0.08
-0.25
-0.10
-0.30
-0.12
1
2
3
4
Magnitude (dB)
-0.10
Differential Phase (°)
-dP, VG = +2V
-0.05
-0.10
-0.10
-0.15
-0.15
-0.20
-0.20
-0.25
-0.25
-0.30
-0.30
-0.35
-0.35
-0.40
-0.40
-0.45
-0.45
-0.50
0
10
20
30
40
50
Deviation from Linear Phase (°)
-0.02
0
AVMAX = 6dB
VG = +2V
-0.05
-0.05
Differential Gain (%)
Figure 14. Large-Signal Pulse Response
0
-dP, VG = +1V
-0.15
1G
Figure 12. Large-Signal Frequency Response
300
-200
100M
Frequency (Hz)
-0.50
Frequency (MHz)
Video Loads
Figure 15. Video Differential Gain and Differential Phase
Figure 16. Gain Flatness, Deviation From Linear Phase
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Typical Characteristics: VS = ±5 V, AVMAX = 6 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 1.33 kΩ, RG = 1.33 kΩ, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
-45
-60
VG = +2V
AVMAX = 6dB
VO = 2VPP
RL = 100W
-55
-60
2nd-Harmonic
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
-50
2nd-Harmonic
-65
-70
3rd-Harmonic
-75
-80
-85
-65
-70
-75
-90
-95
3rd-Harmonic
VG = +2V
AVMAX = 6dB
VO = 2VPP
f = 20MHz
-80
-85
0.1
1
10
100
100
1k
Frequency (MHz)
Resistance (W)
Figure 17. Harmonic Distortion vs Frequency
Figure 18. Harmonic Distortion vs Load Resistance
-40
VG = +2V
AVMAX = 6dB
RL = 100W
f = 20MHz
-55
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
-50
-60
-65
3rd-Harmonic
2nd-Harmonic
-70
-75
VO = 2VPP
AVMAX = 6dB
RL = 100W
f = 20MHz
-45
-50
Maximum Current Through RG Limited
-55
-60
2nd-Harmonic
-65
3rd-Harmonic
-80
-70
0.1
1
10
0.8
1.0
Output Voltage Swing (VPP)
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Figure 19. Harmonic Distortion vs Output Voltage
Figure 20. 20-MHz Harmonic Distortion vs Gain Control
Voltage
40
45
Constant Output Voltage
40
Intercept Point (+dBm)
Intercept Point (+dBm)
38
35
30
36
34
Constant Input Voltage
32
30
28
26
24
25
f = 20MHz
At 50W Matched Load
22
At 50Ω Matched Load
20
20
0
10
20
30
40
50
60
70
0.8
Frequency (MHz)
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Figure 21. 2-Tone, 3rd-Order Intermodulation Intercept
12
1.0
Figure 22. 2-Tone, 3rd-Order Intermodulation Intercept vs
Gain Control Voltage
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Typical Characteristics: VS = ±5 V, AVMAX = 6 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 1.33 kΩ, RG = 1.33 kΩ, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
3
0
Normalized Gain (dB)
Gain (V/V)
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
-3
-6
-9
0.2
0
VG = 1VDC + 10mVPP
-12
-0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
1M
2.0
10M
Gain Control Voltage (V)
Figure 23. Gain vs Gain Control Voltage
1G
Figure 24. Frequency Response
2.5
10
2.0
0.5
0
2.5
-0.5
2.0
1.5
1.0
VG = 2V
-10
Normalized Gain (dB)
1.0
0
VOUT (V)
1.5
VIN (V)
100M
Frequency (Hz)
0.5
-20
-30
-40
VG = 0V
-50
-60
-70
-80
0
-90
-0.5
-100
Time (10ns/div)
VO = 2VPP
1M
10M
100M
1G
Frequency (Hz)
Figure 25. Gain Control Pulse Response
Figure 26. Fully-Attenuated Response
12
2.5
1MHz
2.0
Group Delay (ns)
Group Delay (ns)
10
8
10MHz
6
4
1.5
1.0
0.5
2
VG = +2V
VO = 1VPP
20MHz
0
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
20
40
60
80
Gain Control Voltage (V)
Frequency (MHz)
Figure 27. Group Delay vs Gain Control Voltage
Figure 28. Group Delay vs Frequency
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Typical Characteristics: VS = ±5 V, AVMAX = 6 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 1.33 kΩ, RG = 1.33 kΩ, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
Normalized Gain to Capacitive Load (dB)
RS (W)
100
10
0.1dB Flatness Targeted
0
1
10
100
9
CL = 47pF
0
CL = 100pF
-3
RF
-6
VIN
+VIN
RS
1.33kW
VOUT
VCA820
20W
-9
(1)
1kW
-VIN
NOTE: (1) 1kW is optional.
-12
1M
1k
10M
100M
1G
Frequency (Hz)
Figure 29. Recommended RS vs Capacitive Load
Figure 30. Frequency Response vs Capacitive Load
10
1000
Input Current Noise Density (pA/√Hz
Output Voltage Noise Density (nV/ÖHz)
CL = 10pF
3
Capacitive Load (pF)
VG = +2V
VG = +1V
100
VG = 0V
1
10
100
1k
10k
100k
1M
10M
100
1k
10k
100k
1M
10M
Frequency (Hz)
Frequency (Hz)
Figure 31. Output Voltage Noise Density
14
CL = 22pF
VO = 0.5VPP
6
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Figure 32. Input Current Noise Density
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
7.9 Typical Characteristics: VS = ±5 V, AVMAX = 20 dB
At TA = +25°C, RL = 100 Ω, RF = 1 kΩ, RG = 200 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
300
3
VIN = 50mVPP
f = 20MHz
200
2
1
VOUT (V)
100
VOUT (mV)
VIN = 0.5VPP
f = 20MHz
0
0
-100
-1
-200
-2
-300
-3
Time (10ns/div)
Time (10ns/div)
0
0.06
-0.05
0.04
-0.10
0.02
-0.15
0
-0.20
-0.2
-0.25
-0.4
VG = +2V
AVMAX = 20dB
-0.30
-0.6
-0.35
-0.8
0
10
20
30
40
Output Voltage Noise Density (nV/ÖHz)
Figure 34. Large-Signal Pulse Response
0.08
Deviation From Linear Phase (°)
Magnitude (dB)
Figure 33. Small-Signal Pulse Response
0.05
1000
VG = +2V
100
VG = +1V
VG = 0V
10
50
100
1k
10k
Frequency (MHz)
Figure 35. Gain Flatness, Deviation From Linear Phase
-50
Gain (dB)
-55
1M
10M
Figure 36. Output Voltage Noise Density
-60
VG = +2V
AVMAX = 20dB
VO = 2VPP
RL = 100W
2nd-Harmonic
-60
2nd-Harmonic
-65
-70
3rd-Harmonic
-75
-80
Harmonic Distortion (dBc)
-45
100k
Frequency (Hz)
-65
-70
3rd-Harmonic
-75
-80
-85
VG = +2V
AVMAX = 20dB
VO = 2VPP
f = 20MHz
-90
-85
0.1
1
10
100
100
Frequency (MHz)
1k
Resistance (W)
Figure 37. Harmonic Distortion vs Frequency
Figure 38. Harmonic Distortion vs Load Resistance
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Typical Characteristics: VS = ±5 V, AVMAX = 20 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 1 kΩ, RG = 200 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
-40
-60
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
-55
2nd-Harmonic
-65
-70
3rd-Harmonic
VG = +2V
AVMAX = 20dB
RL = 100W
f = 20MHz
-75
VO = 2VPP
AVMAX = 20dB
RL = 100W
f = 20MHz
-45
-50
Maximum Current Through RG Limited
-55
-60
2nd-Harmonic
-65
3rd-Harmonic
-70
-80
0.1
1
10
0.8
1.0
Output Voltage Swing (VPP)
Figure 39. Harmonic Distortion vs Output Voltage
40
Intercept Point (+dBm)
Intercept Point (+dBm)
1.6
1.8
2.0
40
38
35
30
25
Constant
Output Voltage
36
34
32
30
Constant Input Voltage
28
26
24
f = 20MHz
At 50W Matched Load
22
At 50W Matched Load
20
20
5
10 15 20 25 30 35 40 45
50 55
60 65
0.8
70
1.0
1.2
1.4
1.6
1.8
2.0
Frequency (MHz)
Gain Control Voltage (V)
Figure 41. 2-Tone, 3rd-Order Intermodulation Intercept
(GMAX = +10 V/V)
Figure 42. 2-Tone, 3rd-Order Intermodulation Intercept vs
Gain Control Voltage (fIN = 20 MHz)
3
11
10
9
8
7
0
Normalized Gain (dB)
Gain (V/V)
1.4
Figure 40. 20-MHz Harmonic Distortion vs Gain Control
Voltage
45
6
5
4
3
2
-3
-6
-9
1
0
VG = 1VDC + 10mVPP
-12
-1
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
1M
10M
100M
1G
Frequency (Hz)
Gain Control Voltage (V)
Figure 43. Gain vs Gain Control Voltage
16
1.2
Gain Control Voltage (V)
Figure 44. Gain Control Frequency Response
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
Typical Characteristics: VS = ±5 V, AVMAX = 20 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 1 kΩ, RG = 200 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
2.5
5
2.0
4
0.5
3
Output Voltage (V)
1.0
VOUT (V)
1.5
0
2.5
-0.5
VG (V)
2.0
1.5
100W
Load Line
1W Internal
Power Dissipation
2
25W
Load Line
1
0
50W
Load Line
-1
1W Internal
Power Dissipation
-2
1.0
0.5
-3
0
-4
-0.5
-5
-300
Time (10ns/div)
-200
0
-100
100
200
300
Output Current (mA)
Figure 46. Output Voltage and Current Limitations
Figure 45. Gain Control Pulse Response
30
2.0
20
VO = 2VPP
VIN (V)
-10
-20
-30
-40
1.0
4
0.5
2
0
0
-2
-0.5
Output Voltage
Right Scale
-1.0
VG = 0V
-50
-4
-6
-1.5
-60
-8
-2.0
-70
1M
10M
100M
6
VOUT (V)
Normalized Gain (dB)
0
1.5
VG = +2V
10
8
AVMAX = 20dB
VG = - 0.3V
Input Voltage
Left Scale
1G
Time (40ns/div)
Frequency (Hz)
Figure 47. Fully-Attenuated Response
AVMAX = 20dB
VG = +1V
Output Voltage
Right Scale
1.0
4
0.5
2
0
0
-0.5
Input Voltage
Left Scale
1MHz
6
-2
-1.0
-4
-1.5
-6
-2.0
-8
10
VOUT (V)
Input Voltage (V)
1.5
Figure 48. IRG Limited Overdrive Recovery
12
8
Group Delay (ns)
2.0
8
10MHz
6
4
2
20MHz
0
0
Time (40ns/div)
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Figure 49. Output Limited Overdrive Recovery
Figure 50. Group Delay vs Gain Control Voltage
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Typical Characteristics: VS = ±5 V, AVMAX = 20 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 1 kΩ, RG = 200 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
3.0
Group Delay (ns)
2.5
2.0
1.5
1.0
0.5
VG = +2V
VO = 1VPP
0
0
20
40
60
80
100
Frequency (MHz)
Figure 51. Group Delay vs Frequency
18
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7.10 Typical Characteristics: VS = ±5 V, AVMAX = 40 dB
At TA = +25°C, RL = 100 Ω, RF = 845 Ω, RG = 16.9 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
3
3
0
0
-3
-3
VO = 2VPP
VG = +1V
Gain (dB)
Normalized Gain (dB)
VG = +2V
-6
-9
-6
VO = 5VPP
-9
VO = 7VPP
-12
-12
VIN = 20mVPP
AVMAX = 40dB
RL = 100W
-15
-15
-18
-18
1M
10M
100M
500M
0
50
100
Frequency (Hz)
Figure 52. Small-Signal Frequency Response
300
200
VIN = 5mVPP
f = 20MHz
2
VOUT (V)
VOUT (mV)
250
300
VIN = 50mVPP
f = 20MHz
1
0
0
-100
-1
-200
-2
-300
-3
Time (10ns/div)
Time (10ns/div)
Figure 55. Large-Signal Pulse Response
0.1
0
0
-0.1
-0.05
-0.2
-0.10
-0.3
-0.15
-0.4
-0.20
-0.5
-0.25
-0.6
-0.30
-0.7
10
20
30
40
50
Deviation from Linear Phase (°)
VG = +1V
AVMAX = 40dB
0.05
Output Voltage Noise Density (nV/ÖHz)
Figure 54. Small-Signal Pulse Response
0.10
Magnitude (dB)
200
Figure 53. Large-Signal Frequency Response
3
100
0
150
Frequency (MHz)
1000
VG = +2V
VG = +1V
100
VG = 0V
10
100
1k
10k
100k
1M
10M
Frequency (Hz)
Frequency (MHz)
Figure 56. Gain Flatness
Figure 57. Output Voltage Noise Density
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Typical Characteristics: VS = ±5 V, AVMAX = 40 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 845 Ω, RG = 16.9 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
-35
-45
-50
-55
2nd-Harmonic
-45
Harmonic Distortion (dBc)
-40
Harmonic Distortion (dBc)
-40
VG = +2V
AVMAX = 40dB
VO = 2VPP
RL = 100W
2nd-Harmonic
-60
-65
-70
3rd-Harmonic
-75
-50
-55
3rd-Harmonic
-60
-65
-70
-75
VG = +2V
AVMAX = 40dB
VO = 2VPP
f = 20MHz
-80
-85
-80
-90
0.1
1
10
100
100
1k
Frequency (MHz)
Resistance (W)
Figure 58. Harmonic Distortion vs Frequency
Figure 59. Harmonic Distortion vs Load Resistance
-40
-35
2nd-Harmonic
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
2nd-Harmonic
-45
-50
3rd-Harmonic
-55
VG = +2V
AVMAX = 40dB
RL = 100W
f = 20MHz
-60
-40
-45
-50
Maximum Current Through RG Limited
-55
VO = 2VPP
AVMAX = 40dB
RL = 100W
f = 20MHz
-60
-65
-65
0.1
1
10
0.8
1.0
Output Voltage Swing (VPP)
1.4
1.6
1.8
2.0
Figure 61. 20-MHz Harmonic Distortion vs Gain Control
Voltage
33
35
31
30
29
Intercept Point (+dBm)
Intercept Point (+dBm)
1.2
Gain Control Voltage (V)
Figure 60. Harmonic Distortion vs Output Voltage
27
25
23
21
19
Constant Input Voltage
25
20
Constant Output Voltage
15
10
5
17
f = 20MHz
At 50W Matched Load
At 50W Matched Load
0
15
5
20
3rd-Harmonic
10 15 20 25 30 35 40 45 50 55 60 65 70
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Frequency (MHz)
Gain Control Voltage (V)
Figure 62. 2-Tone, 3rd-Order Intermodulation Intercept
Figure 63. 2-Tone, 3rd-Order Intermodulation Intercept vs
Gain Control Voltage (fIN = 20 MHz)
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SBOS395D – OCTOBER 2007 – REVISED SEPTEMBER 2015
Typical Characteristics: VS = ±5 V, AVMAX = 40 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 845 Ω, RG = 16.9 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
110
100
3
0
Normalized Gain (dB)
Gain (V/V)
90
80
70
60
50
40
30
20
-3
-6
-9
10
VIN = 10mVDC
VG = 1VDC + 10mVPP
0
-12
-10
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
1M
2.0
10M
Gain Control Voltage (V)
Figure 64. Gain vs Gain Control Voltage
1G
Figure 65. Gain Control Frequency
2.5
50
2.0
40
0.5
Normalized Gain (dB)
1.0
VOUT (V)
1.5
0
2.5
-0.5
2.0
VIN (V)
100M
Frequency (Hz)
1.5
1.0
VG = +2V
30
20
10
0
-10
-20
0.5
-30
0
-40
Input-Referred
VO = 2VPP
VG = 0V
-50
-0.5
Time (10ns/div)
1M
10M
100M
1G
Frequency (Hz)
Figure 66. Gain Control Pulse Response
Input Voltage
Left Scale
Output Voltage
Right Scale
2
0
0
-0.1
-2
8
AVMAX = 40dB
VG = 0.85V
6
0.10
4
0.05
2
0
0
-0.05
-8
Input Voltage
Left Scale
-0.10
-0.2
AVMAX = 40dB
VG = +2V
Output Voltage
Right Scale
Output Voltage (V)
0.1
0.15
4
Output Voltage (V)
Input Voltage (V)
0.2
Figure 67. Fully-Attenuated Response
0.20
6
Input Voltage (mV)
0.3
-6
-4
-0.15
-0.3
-6
-4
-0.20
-2
Time (40ns/div)
Time (40ns/div)
Figure 68. Input Limited Overdrive Recovery
Figure 69. Output Limited Overdrive Recovery
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Typical Characteristics: VS = ±5 V, AVMAX = 40 dB (continued)
14
4.0
12
3.5
1MHz
10
3.0
Group Delay (ns)
Group Delay (ns)
At TA = +25°C, RL = 100 Ω, RF = 845 Ω, RG = 16.9 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SO-14 package, unless otherwise noted.
8
10MHz
6
4
2.0
1.5
1.0
2
VG = +2V
VO = 1VPP
0.5
20MHz
0
0
0
22
2.5
0.2
0.4
0.6
0.8
1.0
0
20
40
60
80
Gain Control Voltage (V)
Frequency (MHz)
Figure 70. Group Delay vs Gain Control Voltage
Figure 71. Group Delay vs Frequency
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8 Detailed Description
8.1 Overview
The VCA820 is a voltage controlled variable gain amplifier with differential inputs and a single ended output. The
maximum gain is set by external resistors while the gain range is controlled by an external analog voltage. The
maximum gain is designed for gains of 2 V/V up to 100 V/V and the analog control allows a gain range of over
40 dB. The VCA820 Input consists of two buffers which, together create a fully symmetrical, high impedance
differential input with a typical common mode rejection of 80 dB. The gain set resistor is connected between the
two input buffer output pins, so that the input impedance is independent of the gain settings. The bipolar inputs
have a input voltage range of +1.6 and –2.1 V on ±5-V supplies. The amplifier maximum gain is set by external
resistors, but the internal gain control circuit is controlled by a continuously variable, analog voltage. The gain
control is a multiplier stage which is linear in dB. The gain control input pin operates over a voltage range of 0 V
to 2 V. The VCA820 contains a high-speed, high-current output buffer. The output stage can typically swing ±3.9
V and source and sink ±160 mA. The VCA820 can be operated over a voltage range of ±3.5 V to ±6 V.
8.2 Functional Block Diagram
VG
+VIN
VIN
20
x1
RG+
RG
200
FB
IRG
RF
1k
x2
RG-
VOUT
VOUT
x1
20
-VIN
VREF
VCA820
20
8.3 Feature Description
The VCA820 can be operated with both single ended or differential input signals. The inputs present consistently
high impedance across all gain configurations. By using an analog control signal the amplifier gain is
continuously variable for smooth, glitch-free gain changes. With a large signal bandwidth of 137 MHz and a slew
rate of 1700 V/µs the VCA820 offers linear performance over a wide range of signal amplitudes and gain
settings. The low-impedance/high-current output buffer can drive loads ranging from low impedance transmission
lines to high-impedance, switched-capacitor analog to digital converters. By using closely matched internal
components the VCA820 offers gain accuracy of ±0.4 dB.
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8.4 Device Functional Modes
The VCA820 functions as a differential input, single-ended output variable gain amplifier. This functional mode is
enabled by applying power to the amplifier supply pins and is disabled by turning the power off.
The gain is continuously variable through the analog gain control input. While the gain range is fixed the
maximum gain is set by two external components, Rf and Rg as shown in the Functional Block Diagram. The
maximum gain is equal to 2x (Rf / Rg). This gain is achieved with a 2-V voltage on the gain adjust pin VG. As the
voltage decreases on the VG pin, the gain decreases in a linear in dB fashion with over 40 dB of gain range from
2-V to 0-V control voltage.
As with most other differential input amplifiers, inputs can be applied to either one or both of the amplifier inputs.
The amplifier gain is controlled through the gain control pin.
8.4.1 Maximum Gain of Operation
This section describes the use of the VCA820 in a fixed-gain application in which the VG control pin is set at VG =
+2 V. The tradeoffs described here are with bandwidth, gain, and output voltage range.
In the case of an application that does not make use of the VGAIN, but requires some other characteristic of the
VCA820, the RG resistor must be set such that the maximum current flowing through the resistance IRG is less
than ±2.6-mA typical, or 5.2 mAPP as defined in the Electrical Characteristics: VS = ±5 V table, and must follow
Equation 1.
VOUT
IRG =
AVMAX ´ RG
(1)
As illustrated in Equation 1, once the output dynamic range and maximum gain are defined, the gain resistor is
set. This gain setting in turn affects the bandwidth, because in order to achieve the gain (and with a set gain
element), the feedback element of the output stage amplifier is set as well. Keeping in mind that the output
amplifier of the VCA820 is a current-feedback amplifier, the larger the feedback element, the lower the bandwidth
as the feedback resistor is the compensation element.
Limiting the discussion to the input voltage only and ignoring the output voltage and gain, Figure 1 illustrates the
tradeoff between the input voltage and the current flowing through the gain resistor.
8.4.2 Output Current and Voltage
The VCA820 provides output voltage and current capabilities that are unsurpassed in a low-cost monolithic VCA.
Under no-load conditions at +25°C, the output voltage typically swings closer than 1 V to either supply rails; the
+25°C swing limit is within 1.2 V of either rails. Into a 15-Ω load (the minimum tested load), it is tested to deliver
more than ±160 mA.
The specifications described above, though familiar in the industry, consider voltage and current limits
separately. In many applications, it is the voltage × current, or V-I product, that is more relevant to circuit
operation. Refer to the Output Voltage and Current Limitations plot (Figure 46) in the Typical Characteristics. The
X- and Y-axes of this graph show the zero-voltage output current limit and the zero-current output voltage limit,
respectively. The four quadrants give a more detailed view of the VCA820 output drive capabilities, noting that
the graph is bounded by a Safe Operating Area of 1W maximum internal power dissipation. Superimposing
resistor load lines onto the plot shows that the VCA820 can drive ±2.5 V into 25 Ω or ±3.5 V into 50 Ω without
exceeding the output capabilities or the 1-W dissipation limit. A 100-Ω load line (the standard test circuit load)
shows the full ±3.9-V output swing capability, as shown in the Typical Characteristics.
The minimum specified output voltage and current over-temperature are set by worst-case simulations at the
cold temperature extreme. Only at cold startup do the output current and voltage decrease to the numbers shown
in the Electrical Characteristics tables. As the output transistors deliver power, the respective junction
temperatures increase, increasing the available output voltage swing, and increasing the available output current.
In steady-state operation, the available output voltage and current is always greater than that temperature shown
in the over-temperature specifications because the output stage junction temperatures are higher than the
specified operating ambient.
24
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Device Functional Modes (continued)
8.4.3 Input Voltage Dynamic Range
The VCA820 has a input dynamic range limited to +1.6 V and –2.1 V. Increasing the input voltage dynamic range
can be done by using an attenuator network on the input. If the VCA820 is trying to regulate the amplitude at the
output, such as in an AGC application, the input voltage dynamic range is directly proportional to Equation 2.
VIN(PP) = RG ´ IRG(PP)
(2)
As such, for unity-gain or under-attenuated conditions, the input voltage must be limited to the CMIR of ±1.6 V
(3.2 VPP) and the current (IRQ) must flow through the gain resistor, ±2.6 mA (5.2 mAPP). This configuration sets a
minimum value for RE such that the gain resistor has to be greater than Equation 3.
3.2VPP
RGMIN =
= 615.4W
5.2mAPP
(3)
Values lower than 615.4Ω are gain elements that result in reduced input range, as the dynamic input range is
limited by the current flowing through the gain resistor RG (IRG). If the IRG current is limiting the performance of
the circuit, the input stage of the VCA820 goes into overdrive, resulting in limited output voltage range. Such IRGlimited overdrive conditions are shown in Figure 48 for the gain of 20 dB and Figure 68 for the 40-dB gain.
8.4.4 Output Voltage Dynamic Range
With its large output current capability and its wide output voltage swing of ±3.9-V typical on 100-Ω load, it is
easy to forget other types of limitations that the VCA820 can encounter. For these limitations, careful analysis
must be done to avoid input stage limitation, either voltage or IRG current; also, consider the gain limitation, as
the control pin VG varies, affecting other aspects of the circuit.
8.4.5 Bandwidth
The output stage of the VCA820 is a wideband current-feedback amplifier. As such, the external feedback
resistance is the compensation of the last stage. Reducing the feedback element and maintaining the gain
constant limits the useful range of IRG, and therefore reducing the gain adjust range. For a given gain, reducing
the gain element limits the maximum achievable output voltage swing.
8.4.6 Offset Adjustment
As a result of the internal architecture used on the VCA820, the output offset voltage originates from the output
stage and from the input stage and multiplier core. Figure 87 illustrates how to compensate both sources of the
output offset voltage. Use this procedure to compensate the output offset voltage: starting with the output stage
compensation, set VG = 0 V to eliminate all offset contribution of the input stage and multiplier core. Adjust the
output stage offset compensation potentiometer. Finally, set VG = +1 V to the maximum gain and adjust the input
stage and multiplier core potentiometer. This procedure effectively eliminates all offset contribution at the
maximum gain. Because adjusting the gain modifies the contribution of the input stage and the multiplier core,
some residual output offset voltage remains.
8.4.7 Noise
The VCA820 offers 8.2-nV/√Hz input-referred voltage noise density at a gain of 20 dB and 1.8-pA/√Hz inputreferred current noise density. The input-referred voltage noise density considers that all noise terms, except the
input current noise on each of the two input pins but including the thermal noise of both the feedback resistor and
the gain resistor, are expressed as one term.
This model is formulated in Equation 4 and Figure 86.
eO = AVMAX ´
2 ´ (RS ´ in)2 + en2 + 2 ´ 4kTRS
(4)
A more complete model is illustrated in Figure 88. For additional information on this model and the actual
modeled noise terms, please contact the High-Speed Product Application Support team at www.ti.com.
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Device Functional Modes (continued)
8.4.8 Input and ESD Protection
The VCA820 is built using a very high-speed complementary bipolar process. The internal junction breakdown
voltages are relatively low for these very small geometry devices. These breakdowns are reflected in the table.
All pins on the VCA820 are internally protected from ESD by means of a pair of back-to-back reverse-biased
diodes to either power supply, as shown in Figure 72. These diodes begin to conduct when the pin voltage
exceeds either power supply by approximately 0.7 V. This situation can occur with loss of the amplifier power
supplies while a signal source is still present. The diodes can typically withstand a continuous current of 30 mA
without destruction. To ensure long-term reliability, however, diode current should be externally limited to 10 mA
whenever possible.
+VS
ESD Protection diodes internally
connected to all pins.
External
Pin
Internal
Circuitry
-VS
Figure 72. Internal ESD Protection
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9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
The VCA820 has flexible maximum gain which is set by the Rf and Rg resistors shown in Functional Block
Diagram. The maximum gain is equal to 2x (Rf / Rg). This gain is achieved with a 2-V voltage on the gain adjust
pin VG. As the voltage decreases on the VG pin, the gain decreases in a linear in dB fashion with over 40 dB of
gain range from 2-V to 0-V control voltage.
9.1.1 Design-In Tools
9.1.1.1 Demonstration Boards
Two printed circuit boards (PCBs) are available to assist in the initial evaluation of circuit performance using the
VCA820 in its two package options. Both of these are offered free of charge as unpopulated PCBs, delivered
with a user's guide. The summary information for these fixtures is shown in Table 2.
Table 2. EVM Ordering Information
PRODUCT
PACKAGE
BOARD PART NUMBER
LITERATURE REQUEST NUMBER
VCA820ID
SO-14
DEM-VCA-SO-1B
SBOU050
VCA820IDGS
MSOP-10
DEM-VCA-MSOP-1A
SBOU051
The demonstration fixtures can be requested at the Texas Instruments web site (www.ti.com) through the
VCA820 product folder.
9.1.1.2 Macromodels and Applications Support
Computer simulation of circuit performance using SPICE is often useful when analyzing the performance of
analog circuits and systems. This principle is particularly true for video and RF amplifier circuits where parasitic
capacitance and inductance can play a major role in circuit performance. A SPICE model for the VCA820 is
available through the TI web page. The applications group is also available for design assistance. The models
available from TI predict typical small-signal ac performance, transient steps, dc performance, and noise under a
wide variety of operating conditions. The models include the noise terms found in the electrical specifications of
the relevant product data sheet.
9.1.2 Operating Suggestions
Operating the VCA820 optimally for a specific application requires trade-offs between bandwidth, input dynamic
range and the maximum input voltage, the maximum gain of operation and gain, output dynamic range and the
maximum input voltage, the package used, loading, and layout and bypass recommendations. The Typical
Characteristics have been defined to cover a wide range of external and operating conditions to describe the
VCA820 operation. There are four sections in the Typical Characteristics:
• VS = ±5 V DC Parameters and VS = ±5 V DC and Power-Supply Parameters, which include DC operation and
the intrinsic limitation of a VCA820 design
• VS = ±5 V, AVMAX = 6 dB Gain of 6-dB Operation
• VS = ±5 V, AVMAX = 20 dB Gain of 20-dB Operation
• VS = ±5 V, AVMAX = 40 dB Gain of 40-dB Operation
Where the Typical Characteristics describe the actual performance that can be achieved by using the amplifier
properly, the following sections describe in detail the trade-offs needed to achieve this level of performance.
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Application Information (continued)
9.1.2.1 Package Considerations
The VCA820 is available in both SO-14 and MSOP-10 packages. Each package has, for the different gains used
in the typical characteristics, different values of RF and RG in order to achieve the same performance detailed in
the Electrical Characteristics table.
Figure 73 shows a test gain circuit for the VCA820. Table 3 lists the recommended configuration for the SO-14
and MSOP-10 package.
+VIN
VIN
R1
RF
RG+
50W
Source
50W
RG
VOUT
RG-
50W
Load
R3
-VIN
R2
50W
VG
Figure 73. Test Circuit
Table 3. SO-14 and MSOP-10 RF and RG Configurations
G=2
G = 10
RF
1.33 kΩ
1 kΩ
G = 100
845 Ω
RG
1.33 kΩ
200 Ω
16.9 Ω
There are no differences between the packages in the recommended values for the gain and feedback resistors.
However, the bandwidth for the VCA820IDGS (MSOP-10 package) is lower than the bandwidth for the
VCA820ID (SO-14 package). This difference is true for all gains, but especially true for gains greater than 5 V/V,
as can be seen in Figure 74 and Figure 75. The scale must be changed to a linear scale to view the details.
3
0
AVMAX = 6dB
-3
AVMAX = 14dB
-6
AVMAX = 20dB
AVMAX = 26dB
-9
Normalized Gain (dB)
Normalized Gain (dB)
3
0
AVMAX = 20dB
AVMAX = 6dB
-3
AVMAX = 26dB
-6
AVMAX = 34dB
-9
AVMAX = 34dB
AVMAX = 40dB
AVMAX = 14dB
AVMAX = 40dB
-12
-12
0
28
50
100
150
200
0
50
100
150
200
Frequency (MHz)
Frequency (MHz)
Figure 74. SO-14 Recommended RF and RG vs AVMAX
Figure 75. MSOP-10 Recommended RF and RG vs AVMAX
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9.2 Typical Applications
9.2.1 Wideband Variable Gain Amplifier Operation
0.1µF
+5V
X2Y
@
Cap
-5V
+
2.2µF
+ 2.2µF
VG
+VIN
VIN
50W
x1
RG+
RG
200W
FB
IRG
RF
1kW
x2
RG-
VOUT
VOUT
x1
50W
-VIN
VREF
VCA820
50W
Figure 76. DC-Coupled, AVMAX = 20 dB, Bipolar Supply Specification and Test Circuit
9.2.1.1 Design Requirements
The design shown in Figure 76 supports a single-ended input, continuously variable gain control and a singleended output. This configuration is used to achieve the best performance with a bipolar supply. This circuit also
requires a maximum gain of 10 V/V and low noise.
9.2.1.2 Detailed Design Procedure
The VCA820 provides an exceptional combination of high output power capability with a wideband, greater than
40-dB gain adjust range, linear in dB variable gain amplifier. The VCA820 input stage places the
transconductance element between two input buffers, using the output currents as the forward signal. As the
differential input voltage rises, a signal current is generated through the gain element. This current is then
mirrored and gained by a factor of two before reaching the multiplier. The other input of the multiplier is the
voltage gain control pin, VG. Depending on the voltage present on VG, up to two times the gain current is
provided to the transimpedance output stage. The transimpedance output stage is a current-feedback amplifier
providing high output current capability and high slew rate, 1700 V/μs. This exceptional full-power performance
comes at the price of a relatively high quiescent current (34mA), but a low input voltage noise for this type of
architecture (8.2 nV/√Hz).
Figure 76 shows the dc-coupled, gain of 20 dB, dual power-supply circuit used as the basis of the ±5 V and . For
test purposes, the input impedance is set to 50 Ω with a resistor to ground and the output impedance is set to 50
Ω with a series output resistor. Voltage swings reported in the table are taken directly at the input and output
pins, while output power (dBm) is at the matched 50-Ω load. For the circuit in Figure 76, the total effective load is
100 Ω ∥ 1 kΩ. Note that for the SO-14 package, there is a voltage reference pin, VREF (pin 9). For the SO-14
package, this pin must be connected to ground through a 20-Ω resistor in order to avoid possible oscillations of
the output stage. In the MSOP-10 package, this pin is internally connected to ground and does not require such
precaution. An X2Y® capacitor has been used for power-supply bypassing. The combination of low inductance,
high resonance frequency, and integration of three capacitors in one package (two capacitors to ground and one
across the supplies) of this capacitor contributes to the low second-harmonic distortion reported in the Electrical
Characteristics table. More information on how the VCA820 operates can be found in the section.
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9.2.1.3 Application Curves
3
3
0
VG = +2V
Normalized Gain (dB)
Normalized Gain (dB)
0
-3
-6
-9
-12
-15
AVMAX = 20dB
VIN = 0.2VPP
RL = 100W
-3
VO = 2VPP
-6
-9
VO = 5VPP
-12
VO = 7VPP
-15
VG = +1V
-18
-18
1M
10M
100M
1G
0
50
Figure 77. Small-Signal Frequency Response
30
100
150
200
250
300
350
400
Frequency (MHz)
Frequency (Hz)
Figure 78. Large-Signal Frequency Response
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9.2.2 Difference Amplifier
RF
VIN+
+VIN
RG+
RS
RG
FB
VCA820
RG-VIN
VIN-
20W
RS
Figure 79. Wideband Differential to Single-Ended Amplifier
9.2.2.1 Design Requirements
For a difference amplifier, the design requirements are differential voltage gain, common mode rejection, and
load drive capability. This circuit delivers differential gain of 2* (Rf/Rg), and CMRR as shown in Figure 80.
9.2.2.2 Detailed Design Procedure
Because both inputs of the VCA820 are high-impedance, a difference amplifier can be implemented without any
major problem. This implementation is shown in Figure 79. This circuit provides excellent common-mode
rejection ratio (CMRR) as long as the input is within the CMRR range of –2.1 V to +1.6 V. Note that this circuit
does not make use of the gain control pin, VG. Also, it is recommended to choose RS such that the pole formed
by RS and the parasitic input capacitance does not limit the bandwidth of the circuit. The common-mode rejection
ratio for this circuit implemented in a gain of 20 dB for VG = +2 V is shown in Figure 80. Note that because the
gain control voltage is fixed and is normally set to +2 V, the feedback element can be reduced in order to
increase the bandwidth. When reducing the feedback element make sure that the VCA820 is not limited by
common-mode input voltage, the current flowing through RG, or any other limitation described in this data sheet.
9.2.2.3 Application Curve
Common-Mode Rejection Ratio (dB)
95
90
85
80
75
70
65
60
55
50
45
Input-Referred
40
100k
1M
10M
100M
Frequency (Hz)
Figure 80. Common-Mode Rejection Ratio
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9.2.3 Differential Equalizer
VIN1
RF
+VIN
RG+
RS
R1
FB
RG
VCA820
C1
RGVIN2
-VIN
20W
RS
Figure 81. Differential Equalizer
9.2.3.1 Design Requirements
Signals that travel over a length of cable experience an attenuation that is proportional to the square root of the
frequency. For this reason, a flat response amplifier will not restore the original signal. To replicate the original
signal, the higher frequency signal components require more gain. The circuit in Figure 81 has one stage of
frequency shaping to help restore a signal transmitted along a cable. If needed, additional frequency shaping
stages can be added as shown in Figure 82.
9.2.3.2 Detailed Design Procedure
If the application requires frequency shaping (the transition from one gain to another), the VCA820 can be used
advantageously because its architecture allows the application to isolate the input from the gain setting elements.
Figure 81 shows an implementation of such a configuration. The transfer function is shown in Equation 5.
RF
1 + sRGC1
´
G=2´
RG
1 + sR1C1
(5)
This transfer function has one pole, P1 (located at RGC1), and one zero, Z1 (located at R1C1). When equalizing an
RC load, RL and CL, compensate the pole added by the load located at RLCL with the zero Z1. Knowing RL, CL,
and RG allows the user to select C1 as a first step and then calculate R1. Using RL = 75 Ω, CL = 100 pF and
wanting the VCA820 to operate at a gain of +2 V/V, which gives RF = RG = 1.33 kΩ, allows the user to select C1
= 5 pF to ensure a positive value for the resistor R1. With all these values known, R1 can be calculated to be 170
Ω. The frequency response for both the initial, unequalized frequency response and the resulting equalized
frequency response are illustrated in Figure 82.
9.2.3.3 Application Curve
9
Equalized Frequency
Response
6
3
Gain (dB)
0
-3
-6
Initial Frequency Response
of VCA820 with RC Load
-9
-12
-15
-18
-21
-24
1M
10M
100M
1G
Frequency (Hz)
Figure 82. Differential Equalization of an RC Load
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9.2.4 Differential Cable Equalizer
VIN
R2
1.33kW
+VIN
R8
50W
RG+
R18
40kW
R17
17.5kW
R21
8.7kW
R9
1.27kW
R3
1.33kW
C7
100nF
VCA820
RG-VIN
C6
120nF
VOUT
FB
VREF
GND
VG
R1
20W
R10
75W
VOUT
75W Load
R5
50W
C5
1.42pF
VG = +2VDC
C9
10µF
Figure 83. Differential Cable Equalizer
9.2.4.1 Design Requirements
Signals that travel over a length of cable experience an attenuation that is proportional to the square root of the
frequency. For this reason, a fixed bandwidth amplifier will not restore the original signal. To replicate the original
signal, the higher frequency signal components require more gain. The circuit in Figure 83 has multiple stages of
frequency shaping to help restore a signal transmitted along a cable. This circuit is similar to the one shown in
Figure 81, but is much more accurate in replicating the 1/(sqrt(f)) frequency response shape.
9.2.4.2 Detailed Design Procedure
A differential cable equalizer can easily be implemented using the VCA820. An example of a cable equalization
for 100 feet of Belden Cable 1694F is illustrated in Figure 83, with the result for this implementation shown in
Figure 84. This implementation has a maximum error of 0.2 dB from dc to 40 MHz.
Note that this implementation shows the cable attenuation side-by-side with the equalization in the same plot. For
a given frequency, the equalization function realized with the VCA820 matches the cable attenuation. The circuit
in Figure 83 is a driver circuit. To implement a receiver circuit, the signal is received differentially between the
+VIN and –VIN inputs.
For a detailed design procedure, refer to to SBOA124.
9.2.4.3 Application Curve
2.0
1694F Cable Attenuation (dB)
Equalizer Gain (dB)
Cable Attenuations
1.5
1.0
VCA820 with
Equalization
0.5
0
-0.5
-1.0
1
10
100
Frequency (MHz)
Figure 84. Cable Attenuation versus Equalizer Gain
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9.2.5 AGC Loop
1kW
VIN
+VIN
RG+ FB
50W
200W
50W
VCA820 Out
RG- VG
-VIN
50W
OPA695
50W
VOUT
950W
100W
50W
0.1mF
1kW
1N4150
OPA820
VREF
Figure 85. AGC Loop
9.2.5.1 Design Requirements
When dynamic signal amplitude correction is required, an AGC loop will provide real-time gain control. The
requirements for this circuit are fast gain control response and linear in dB gain control. The time constant of the
loop is set with the 0.1-µF capacitor and the 1-kΩ resistor. The OPA695 provides additional load driving
capability.
9.2.5.2 Detailed Design Procedure
In the typical AGC loop shown in Figure 85, the OPA695 follows the VCA820 to provide 40 dB of overall gain.
The output of the OPA695 is rectified and integrated by an OPA820 to control the gain of the VCA820. When the
output level exceeds the reference voltage (VREF), the integrator ramps down reducing the gain of the AGC loop.
Conversely, if the output is too small, the integrator ramps up increasing the net gain and the output voltage.
34
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9.3 System Examples
RF
in
RS
+VIN
RG+
ei
RG
∗
FB
eO
VCA820
RG-V IN
4kTRS
in
RS
∗
4kTRS
NOTE: RF and RG are noiseless.
Figure 86. Simple Noise Model
+5V
Output Stage Offset
Compensation Circuit
10kW
4kW
0.1mF
-5V
RF
VIN
+VIN
RG+
50W
RG
FB
VOUT
VCA820
RG-VIN
+5V
1kW
50W
10kW
0.1mF
-5V
Input Stage and Multiplexer Core
Offset Compensation Circuit
Figure 87. Adjusting the Input and Output Voltage Sources
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VG
inINPUT
VG
+VIN
V+
RS1
*
*
enINPUT
4kTRS1
FB
x1
RF
+RG
*
inINPUT
VOUT
RG
(Noiseless)
ICORE
eO
iinOUTPUT
-RG
VREF
x1
RF
enOUTPUT
-VIN
V-
4kTRF
*
*
RS2
enINPUT
iniOUTPUT
*
4kTRF
inINPUT
GND
*
4kTRS2
Figure 88. Full Noise Model
36
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10 Power Supply Recommendations
High-speed amplifiers require low inductance power supply traces and low ESR bypass capacitors. The power
supply voltage should be centered on the desired amplifier output voltage, so for ground referenced output
signals, split supplies are required. The power supply voltage should be from 7 V to 12 V.
11 Layout
11.1 Layout Guidelines
Achieving optimum performance with a high-frequency amplifier such as the VCA820 requires careful attention to
printed circuit board (PCB) layout parasitics and external component types. Recommendations to optimize
performance include:
• Minimize parasitic capacitance to any ac ground for all of the signal I/O pins. This recommendation includes
the ground pin (pin 2). Parasitic capacitance on the output can cause instability: on both the inverting input
and the noninverting input, it can react with the source impedance to cause unintentional band limiting. To
reduce unwanted capacitance, a window around the signal I/O pins should be opened in all of the ground and
power planes around those pins. Otherwise, ground and power planes should be unbroken elsewhere on the
board. Place a small series resistance (greater than 25 Ω) with the input pin connected to ground to help
decouple package parasitics.
• Minimize the distance (less than 0.25”) from the power-supply pins to high-frequency 0.1-μF decoupling
capacitors. At the device pins, the ground and power plane layout should not be in close proximity to the
signal I/O pins. Avoid narrow power and ground traces to minimize inductance between the pins and the
decoupling capacitors. The power-supply connections should always be decoupled with these capacitors.
Larger (2.2 μF to 6.8 μF) decoupling capacitors, effective at lower frequencies, should also be used on the
main supply pins. These capacitors may be placed somewhat farther from the device and may be shared
among several devices in the same area of the PCB.
• Careful selection and placement of external components preserve the high-frequency performance of the
VCA820. Resistors should be a very low reactance type. Surface-mount resistors work best and allow a
tighter overall layout. Metal-film and carbon composition, axially-leaded resistors can also provide good highfrequency performance. Again, keep the leads and PCB trace length as short as possible. Never use wirewound type resistors in a high-frequency application. Because the output pin is the most sensitive to parasitic
capacitance, always position the series output resistor, if any, as close as possible to the output pin. Other
network components, such as inverting or non-inverting input termination resistors, should also be placed
close to the package.
• Connections to other wideband devices on the board may be made with short direct traces or through
onboard transmission lines. For short connections, consider the trace and the input to the next device as a
lumped capacitive load. Relatively wide traces (50 mils to 100 mils, or 1.27 mm to 2.54 mm) should be used,
preferably with ground and power planes opened up around them.
• Socketing a high-speed part like the VCA820 is not recommended. The additional lead length and pin-to-pin
capacitance introduced by the socket can create an extremely troublesome parasitic network, which can
make it almost impossible to achieve a smooth, stable frequency response. Best results are obtained by
soldering the VCA820 onto the board.
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11.2 Layout Example
Figure 89. VCA820 Recommended Layout
11.3 Thermal Considerations
The VCA820 does not require heatsinking or airflow in most applications. The maximum desired junction
temperature sets the maximum allowed internal power dissipation as described in this section. In no case should
the maximum junction temperature be allowed to exceed +150°C.
Operating junction temperature (TJ) is given by Equation 6:
TJ = TA + PD ´ qJA
(6)
The total internal power dissipation (PD) is the sum of quiescent power (PDQ) and additional power dissipated in
the output stage (PDL) to deliver load power. Quiescent power is simply the specified no-load supply current
times the total supply voltage across the part. PDL depends on the required output signal and load; for a
grounded resistive load, however, it is at a maximum when the output is fixed at a voltage equal to one-half of
either supply voltage (for equal bipolar supplies). Under this worst-case condition, PDL = VS2/(4 × RL), where RL is
the resistive load.
Note that it is the power in the output stage and not in the load that determines internal power dissipation. As a
worst-case example, compute the maximum TJ using a VCA820ID (SO-14 package) in the circuit of Figure 76
operating at maximum gain and at the maximum specified ambient temperature of +85°C with a DC output
voltage at half the supply into a 100-ohm load.
2
PD = 10V(38mA) + 5 /(4 ´ 100W) = 442.5mW
(7)
Maximum TJ = +85°C + (0.449W ´ 80°C/W) = 120.5°C
(8)
This maximum operating junction temperature is well below most system level targets. Most applications should
be lower because an absolute worst-case output stage power was assumed in this calculation of VCC/2, which is
beyond the output voltage range for the VCA820.
38
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12 Device and Documentation Support
12.1 Device Support
12.1.1 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT
CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES
OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER
ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
12.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
12.3 Trademarks
E2E is a trademark of Texas Instruments.
X2Y is a registered trademark of X2Y Attenuators LLC.
All other trademarks are the property of their respective owners.
12.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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PACKAGE OPTION ADDENDUM
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10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
VCA820ID
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
VCA820ID
VCA820IDGSR
ACTIVE
VSSOP
DGS
10
2500
RoHS & Green
NIPDAUAG
Level-2-260C-1 YEAR
-40 to 85
BOQ
VCA820IDGST
ACTIVE
VSSOP
DGS
10
250
RoHS & Green
NIPDAUAG
Level-2-260C-1 YEAR
-40 to 85
BOQ
VCA820IDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
VCA820ID
(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)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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