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VCA821
SBOS407D – DECEMBER 2007 – REVISED MAY 2016
VCA821 Ultra-Wideband, > 40-dB Gain Adjust Range, Linear in dB
Variable Gain Amplifier
1 Features
3 Description
•
The VCA821 device is a DC-coupled, wideband,
linear in dB, continuously variable, voltage-controlled
gain amplifier. It provides a differential input to singleended 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).
1
•
•
•
•
•
•
710-MHz Small-Signal Bandwidth
(G = +2 V/V)
320 MHz, 4 VPP Bandwidth (G = +10 V/V)
0.1-dB Gain Flatness to 135 MHz
2500 V/μs Slew Rate
> 40-dB Gain Adjust Range
High Gain Accuracy: 20 dB ±0.3 dB
High Output Current: ±90 mA
The VCA821 device 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 6 dB and 32 dB.
Operating from ±5-V supplies, the gain control
voltage for the VCA821 device adjusts the gain
linearly in dB as the control voltage varies from 0V to
+2 V. For example, set at a maximum gain of 20 dB,
the VCA821 device provides 20 dB, at VG = +2 V, to
less than –20 dB at VG = 0 V. The VCA821 device
offers excellent gain linearity. For a 20-dB maximum
gain, and a gain-control input voltage varying
between +1 V and +2 V, the gain does not deviate by
more than ±0.3 dB (maximum at +25°C).
2 Applications
•
•
•
•
•
AGC Receivers With RSSI
Differential Line Receivers
Pulse Amplitude Compensation
Variable Attenuators
Voltage-Tunable Active Filters
Device Information(1)
PART NUMBER
VCA821
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.
Differential Equalizer
VIN1
Differential Equalization of an RC Load
9
RF
+VIN
RG+
R1
3
RL
FB
RG
0
VOUT
VCA821
C1
CL
RG–
VIN2
–VIN
20W
RS
Gain (dB)
RS
Equalized Frequency Response
6
Initial Frequency Response
of the VCA821 with RC Load
-3
-6
-9
-12
-15
-18
Copyright © 2016, Texas Instruments Incorporated
-21
-24
1M
10M
100M
1G
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.
VCA821
SBOS407D – DECEMBER 2007 – REVISED MAY 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Device Comparison Table.....................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
5
7.1
7.2
7.3
7.4
7.5
7.6
7.7
Absolute Maximum Ratings ...................................... 5
ESD Ratings ............................................................ 5
Recommended Operating Conditions....................... 5
Thermal Information .................................................. 5
Electrical Characteristics: VS = ±5 V......................... 6
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 = 32
dB............................................................................. 19
8
9
Parameter Measurement Information ................ 22
Detailed Description ............................................ 23
9.1 Overview ................................................................. 23
9.2 Feature Description................................................. 23
9.3 Device Functional Modes........................................ 23
10 Application and Implementation........................ 27
10.1 Application Information.......................................... 27
10.2 Typical Applications .............................................. 29
10.3 System Examples ................................................ 34
11 Power Supply Recommendations ..................... 35
12 Layout................................................................... 36
12.1 Layout Guidelines ................................................. 36
12.2 Layout Example .................................................... 37
12.3 Thermal Considerations ........................................ 37
13 Device and Documentation Support ................. 38
13.1
13.2
13.3
13.4
13.5
Device Support......................................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
38
38
38
38
38
14 Mechanical, Packaging, and Orderable
Information ........................................................... 38
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision C (October 2015) to Revision D
Page
•
Changed Output voltage swing values ................................................................................................................................... 8
•
Changed Output current values ............................................................................................................................................. 8
Changes from Revision B (December 2008) to Revision C
Page
•
Added Pin Configuration and Functions section, ESD Ratings table, Recommended Operating Conditions 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
•
Deleted Ordering Information table ........................................................................................................................................ 1
Changes from Revision A (August 2008) to Revision B
•
Revised second paragraph in Wideband Variable Gain Amplifier Operation section describing pin 9................................ 29
Changes from Original (December 2007) to Revision A
•
2
Page
Page
Changed storage temperature range rating in Absolute Maximum Ratings table from –40°C to +125°C to –65°C to
+125°C.................................................................................................................................................................................... 5
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
5 Device Comparison Table
VCA821 Related Products
DUALS
GAIN ADJUST RANGE
(dB)
INPUT NOISE
(nV/√Hz)
SIGNAL BANDWIDTH (MHz)
VCA810
—
—
VCA2612
80
2.4
35
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
6.0
420
VCA822
—
40
8.2
150
VCA824
—
40
6.0
420
SINGLES
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VCA821
SBOS407D – DECEMBER 2007 – REVISED MAY 2016
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6 Pin Configuration and Functions
D Package
14-Pin SOIC
Top View
DGS Package
10-Pin VSSOP
Top View
+VCC
1
14 +VCC
VG
2
13 NC
+VIN
3
12 FB
+RG
4
11 GND
-RG
5
10 VOUT
-VIN
6
9
VREF
-VCC
7
8
-VCC
FB
1
10 GND
+VCC
2
9
VOUT
VG
3
8
-VCC
+VIN
4
7
-VIN
+RG
5
6
-RG
NC = No Connection
Pin Functions
PIN
NAME
SOIC
VSSOP
I/O
DESCRIPTION
FB
12
1
I
GND
11
10
—
Ground
NC
13
—
—
No Connection
+RG
4
5
I
Gain Set Resistor
–RG
5
6
I
Gain Set Resistor
+VCC
1, 14
2
P
Positive Supply
–VCC
7, 8
8
P
Negative Supply
+VIN
3
4
I
Gain Control
–VIN
6
7
I
Inverting Input
VG
2
3
I
Noninverting Input
VOUT
10
9
O
Output
VREF
9
—
I
Output Voltage Reference
4
Feedback Resistor Input
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
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
±6.5
V
See Thermal Information
Input Voltage
±VS
V
Lead Temperature (soldering, 10 s)
260
°C
Junction Temperature (TJ)
150
°C
Junction Temperature (TJ) Maximum Continuous Operation
140
°C
125
°C
Storage Temperature (Tstg)
(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 JESD22-C101 (2)
±1000
Machine Model
±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
VCA821
THERMAL METRIC
(1)
D [SOIC]
DGS [VSSOP]
14 PINS
10 PINS
UNIT
RθJA
Junction-to-ambient thermal resistance
90.3
173.1
°C/W
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)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
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VCA821
SBOS407D – DECEMBER 2007 – REVISED MAY 2016
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7.5 Electrical Characteristics: VS = ±5 V
At AVMAX = 20 dB, RF = 402 Ω, RG = 80 Ω, RL = 100 Ω, unless otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
UNIT
TEST
LEVEL (1)
710
MHz
C
420
MHz
C
170
MHz
C
320
MHz
C
MHz
B
MHz
C
V/μs
B
ns
B
ns
C
dBc
B
dBc
B
TYP
MAX
AC PERFORMANCE
Small-signal bandwidth
Large-signal bandwidth
G = 6dB, VO = 500mVPP G = 20dB, VO = 500mVPP G
= 40dB, VO = 500mVPP
G = 20dB, VO = 4VPP
+25° C
Gain control bandwidth
VO = 200mVPP
(2)
0° C to 70° C
240
(3)
–40° C to +85° C
Bandwidth for 0.1dB flatness
G = 20dB, VO = 5V Step
0° C to 70° C
+25° C
1800
(3)
G = 20dB, VO = 5V Step
0° C to 70° C
1.5
(3)
VO = 2VPP, f = 20MHz
1.9
11
0° C to 70° C
+25° C
VO = 2VPP, f = 20MHz
1.8
1.9
(3)
(2)
–64
(3)
–40° C to +85° C
Harmonic distortion, 3rd -harmonic
1700
G = 20dB, VO = 5V Step
+25° C
Harmonic distortion, 2nd-harmonic
2500
1700
(3)
(2)
–40° C to +85° C
Settling time to 0.01%
235
135
(2)
–40° C to +85° C
Rise-and-fall time
235
(3)
G = 20dB, VO = 200mVPP
+25° C
Slew rate
330
–64
(3)
(2)
0° C to 70° C
–64
–61
(3)
–40° C to +85° C
–66
–63
–61
(3)
–61
Input voltage noise
f > 100kHz
6.0
nV/√Hz
C
Input current noise
f > 100kHz
2.6
pA/√Hz
C
dB
A
GAIN CONTROL
+25° C
Absolute gain error
GMAX = 20dB, VG = 2V
(2)
0° C to 70° C
±0.1
(3)
–40° C to +85° C
±0.4
±0.5
(3)
±0.6
Vctrl0
0.85
V
C
VSlope
0.09
V
C
dB
A
dB
A
μA
A
nA/°C
B
MΩ || pF
C
mV
A
μV/°C
B
+25° C
Absolute gain error
GMAX = 20dB, VG = 1V,
(G = 18.06 dB)
(2)
0° C to 70° C
±0.3
(3)
–40° C to +85° C
+25° C
Gain at VG = 0.2V
Relative to max gain
Gain control bias current
–26
0° C to 70° C
–23
10
(3)
–40° C to +85° C
–40° C to +85° C
16
16.6
(3)
16.7
(3)
Average gain control bias current drift
–24
–24
(3)
(2)
0° C to 70° C
±0.6
(3)
–40° C to +85° C
+25° C
±0.5
(3)
(2)
0° C to 70° C
±0.4
±12
(3)
±12
Gain control input impedance
1.5 || 0.6
DC PERFORMANCE
+25° C
Input offset voltage
G = 20dB, VCM = 0V, VG
= 1V
(2)
0° C to 70° C
±4
(3)
–40° C to +85° C
Average input offset voltage drift
(1)
(2)
(3)
6
G = 20dB, VCM = 0V, VG
= 1V
0° C to 70° C
(3)
(3)
–40° C to +85° C
±17
±17.8
±19
30
(3)
30
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 for +25°C tested specifications.
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 = 402 Ω, RG = 80 Ω, RL = 100 Ω, unless otherwise noted.
PARAMETER
TEST CONDITIONS
+25° C
Input bias current
G = 20dB, VCM = 0V, VG
= 1V
MIN
(2)
0° C to 70° C
G = 20dB, VCM = 0V, VG
= 1V
0° C to 70° C
G = 20dB, VCM = 0V, VG
= 1V
G = 20dB, VCM = 0V, VG
= 1V
+25° C
lRG
MAX
Max current through gain resistance
0° C to 70° C
B
μA
A
nA/°C
B
mA
B
V
A
V
A
dB
A
0.9 || 0.6
MΩ || pF
C
1 || 2
MΩ || pF
C
31
90
(3)
90
±0.5
±3.5
(3)
–40° C to +85° C
±16
(3)
±16
±2.6
(3)
–40° C to +85° C
±2.5
±3.2
(3)
(2)
0° C to 70° C
nA/°C
29
(3)
–40° C to +85° C
Average input offset current drift
A
25
(3)
(2)
0° C to 70° C
μA
19
(3)
–40° C to +85° C
+25° C
Input offset current
TEST
LEVEL (1)
MAX
(3)
–40° C to +85° C
Average input bias current drift
UNIT
TYP
±2.55
±2.55
(3)
±2.5
INPUT
+25° C
Most positive common mode input voltage
RL = 100Ω
(2)
0° C to 70° C
+1.6
(3)
–40° C to +85° C
+25° C
Most negative common mode input voltage
RL = 100Ω
+25° C
VCM = ±0.5V
+1.6
–2.1
(3)
–40° C to +85° C
Common-mode rejection ratio
(3)
(2)
0° C to 70° C
(3)
–2.1
65
(3)
–40° C to +85° C
-2.1
–2.1
(2)
0° C to 70° C
+1.6
+1.6
80
60
(3)
Input impedance, differential
Input impedance, common-mode
60
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Electrical Characteristics: VS = ±5 V (continued)
At AVMAX = 20 dB, RF = 402 Ω, RG = 80 Ω, RL = 100 Ω, unless otherwise noted.
UNIT
TEST
LEVEL (1)
V
A
V
A
mA
A
0.01
Ω
C
Specified operating voltage
±5
V
C
Minimum operating voltage
±3.5
V
C
V
A
mA
A
mA
A
dB
A
PARAMETER
TEST CONDITIONS
MIN
TYP
±3.6
±3.9
MAX
OUTPUT
+25° C
RL = 1kΩ
(2)
0° C to 70° C
(3)
–40° C to +85° C
Output voltage swing
+25° C
RL = 100Ω
VO = 0V, RL = 10Ω
(3)
–3.3/+3.6
–3.2
+3.3
–3.0
+3.2
–2.9
+60
(3)
–40° C to +85° C
Output impedance
(3)
(2)
0° C to 70° C
±3.3
±3.5
(3)
–40° C to +85° C
Output current
(3)
(2)
0° C to 70° C
+25° C
±3.4
–55/+90
–50
+50
–42
+45
–38
G = +10V/V, f > 100kHz
POWER SUPPLY
+25° C
Maximum operating voltage
(2)
0° C to 70° C
±6
(3)
–40° C to +85° C
±6
(3)
±6
+25° C
Maximum quiescent current
VG = 1V
(2)
0° C to 70° C
34
(3)
–40° C to +85° C
+25° C
Minimum quiescent current
VG = 1V
+25° C
Power-supply rejection ratio
34
31.5
–61
(3)
–40° C to +85° C
32.5
32
(3)
(2)
0° C to 70° C
36
(3)
–40° C to +85° C
–PSR
R
(3)
(2)
0° C to 70° C
35
35.5
–68
–59
(3)
–58
THERMAL CHARACTERISTICS
Specified operating range, D package
θ JA
8
–40 to +85
VSSOP-10 (DGS)
°C
C
130
°C/W
C
80
°C/W
C
Junction-to-ambient thermal resistance
SOIC-14 (D)
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
7.6 Typical Characteristics: VS = ±5 V, DC Parameters
At TA = +25°C, RL = 100 Ω, VG = +2 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
IRG = 2.6mA
AVMAX(V/V) = 2 ´ [RF/VIN(VPP)] ´ 2 ´ IRG (AP)
35
30
25
VO = 1VPP
20
VO = 2VPP
15
VO = 4VPP
10
VO = 3VPP
5
0
0.1
10
100
1k
100
1k
Gain Resistor (W)
Figure 1. Maximum Differential Input Voltage
vs RG
IRG = 2.6mA
AVMAX(V/V) = 2 ´ [RF/VIN(VPP)] ´ 2 ´ IRG (AP)
50
10
40
Absolute
Error
8
RF = 4kW
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
0.6
0.8
1.0
1.2
1.4
Figure 3. Maximum Gain Adjust Range
vs Peak-to-Peak Output Voltage
Figure 4. Gain Error Band
vs Gain Control Voltage
20
450
Feedback Resistor (W)
460
Equation
A(V/V) = K ´
-40
RF
´
RG
1
( VV
G0
1+e
- VG
SLOPE
)
-60
Data
VCTRL0 = 0.85V
VSLOPE = 90mV
-80
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
1.6
1.8
2.0
For > 40dB Gain Adjust Range
440
430
420
410
400
NOTE: -3dB bandwidth varies with package type.
See the Applications Information section for more details.
390
-100
0
0.4
Control Voltage (V)
40
-20
0.2
Output Voltage (VPP)
0
Gain (dB)
Absolute
Error
RF = 3kW
Gain (V/V)
Maximum Gain Adjust Range (dB)
Figure 2. Maximum Gain Adjust Range vs RF
12
60
10k
Feedback Resistor (W)
1
Control Voltage (V)
10
100
AVMAX (V/V)
Figure 5. Gain Error Band
vs Gain Control Voltage
Figure 6. Recommended RF 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 = +2 V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
36
36
+IQ
+IQ
35
-IQ
-IQ
Quiescent Current (mA)
Quiescent Current (mA)
35
34
33
32
31
34
33
32
31
30
30
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
0.6
0.4
Gain Control Voltage (V)
Figure 7. Supply Current vs Control Voltage
(AVMAX = 6 dB)
1.2
1.4
1.6
1.8
0
30
25
-0.5
Input Offset Voltage (mV)
35
+IQ
34
33
32
31
30
29
Input Bias Current (IB)
Right Scale
-1.0
15
-2.0
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
10
Input Offset Voltage (VOS)
Left Scale
-2.5
5
0
-3.0
-3.5
-5
Right Scale
10 x Input Offset Current (IOS)
-10
-4.5
0.2
20
-1.5
-4.0
0
2.0
-50
Gain Control Voltage (V)
-25
0
25
50
75
100
Input Bias and Offset Current (mA)
-IQ
36
Quiescent Current (mA)
1.0
Figure 8. Supply Current vs Control voltage
(AVMAX = 20 dB)
37
-15
125
Temperature (°C)
Figure 9. Supply Current vs Control Voltage
(AVMAX = 32 dB)
10
0.8
Gain Control Voltage (V)
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Figure 10. Typical DC Drift vs Temperature
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
7.8 Typical Characteristics: VS = ±5 V, AVMAX = 6 dB
At TA = 25°C, RL = 100 Ω, RF = 453 Ω, RG = 453 Ω, VG = 2 V, VIN = single-ended input on +VIN with –VIN at ground, and SOIC
package, unless otherwise noted.
3
300
VG = +1V
200
Output Voltage (mV)
Normalized Gain (dB)
0
-3
VG = +2V
-6
-9
-12
AVMAX = 6dB
VIN = 1VPP
RL = 100W
-15
-18
1M
100
0
-100
-200
VIN = 250mVPP
f = 20MHz
10M
100M
1G
2G
-300
Time (10ns/div)
Frequency (Hz)
Figure 12. Small-Signal Pulse Response
Figure 11. Small-Signal Frequency Response
-0.1
2.0
1.0
0
-0.005
-dG, VG = 0V
-0.2
-0.010
-0.015
-0.3
-0.4
-0.020
-dP, VG = 0V
-0.025
-0.5
-0.6
-1.0
-0.7
-2.0
-0.8
-0.030
-dP, VG = +1V
-0.035
-0.040
-dG, VG = +1V
-0.045
-0.9
1
-3.0
Differential Phase (°)
Output Voltage (V)
3.0
0
0
VIN = 2VPP
f = 20MHz
Differential Gain (%)
4.0
2
Time (10ns/div)
3
4
Number of Video Loads
Figure 13. Large-Signal Pulse Response
0.2
Figure 14. Composite Video dG/dP
0.15
-60
0.10
0
0.05
0
-0.1
Right Scale
-0.2
-0.05
-0.3
-0.10
-0.4
-0.15
AVMAX = 6dB
VG = +2V
-0.5
0
50
-0.20
100
150
200
Harmonic Distortion (dBc)
0.1
Deviation from Linear Phase (°)
Magnitude (dB)
Left Scale
-65
-70
3rd Harmonic
-75
-80
AVMAX = 6dB
VG = +2V
VO = 2VPP
RL = 100W
2nd Harmonic
-85
-90
0.1
Frequency (MHz)
1
10
100
Frequency (MHz)
Figure 15. Gain Flatness, Deviation From Linear Phase
Figure 16. Harmonic Distortion vs Frequency
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Typical Characteristics: VS = ±5 V, AVMAX = 6 dB (continued)
At TA = 25°C, RL = 100 Ω, RF = 453 Ω, RG = 453 Ω, VG = 2 V, VIN = single-ended input on +VIN with –VIN at ground, and SOIC
package, unless otherwise noted.
-30
AVMAX = 6dB
VG = +2V
VO = 2VPP
f = 20MHz
-65
-70
2nd Harmonic
-75
-80
AVMAX = 6dB
VG = +2V
RL = 100W
f = 20MHz
-35
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
-60
3rd Harmonic
-85
-40
-45
Maximum Current
Through RG Limited
-50
-55
-60
-65
2nd Harmonic
-70
-75
3rd Harmonic
-80
-85
-90
100
0.1
1k
1
Figure 17. Harmonic Distortion vs Load Resistance
-10
AVMAX = 6dB
VO = 2VPP
RL = 100W
f = 20MHz
-30
36
Intercept Point (+dBm)
Harmonic Distortion (dBc)
Figure 18. Harmonic Distortion vs Output Voltage
38
-20
-40
Maximum Current Through RG Limited
-50
-60
2nd Harmonic
-70
34
32
30
28
3rd Harmonic
-80
26
-90
24
At 50W Matched Load
0.8
1.0
1.2
1.4
1.6
1.8
0
2.0
10
20
30
50
60
70
80
90
100
1.8
2.0
Figure 20. Two-Tone, Third-Order
Intermodulation Intercept
Figure 19. Harmonic Distortion vs Gain Control Voltage
40
2.2
2.0
1.8
1.6
1.4
Constant Input Voltage
35
30
Gain (V/V)
Intercept Point (+dBm)
40
Frequency (MHz)
Gain Control Voltage (V)
Constant Output Voltage
25
20
1.2
1.0
0.8
0.6
0.4
15
10
0.2
f = 20MHz
At 50W Matched Load
0
-0.2
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
Gain Control Voltage (V)
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Gain Control Voltage (V)
Figure 21. Two-Tone, Third-Order Intermodulation Intercept
vs Gain Control Voltage
12
10
Output Voltage Swing (VPP)
Resistance (W)
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Figure 22. Gain 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 = 453 Ω, RG = 453 Ω, VG = 2 V, VIN = single-ended input on +VIN with –VIN at ground, and SOIC
package, unless otherwise noted.
4
VIN = 1VDC
3
2
1
-3
Input Voltage (V)
Normalized Gain (dB)
0
-6
-9
VG = 1VDC + 10mVPP
VIN =0.5VDC
2.5
0
2.0
-1
Output Voltage (V)
3
1.5
1.0
0.5
0
-12
10M
1M
100M
1G
-0.5
Time (10ns/div)
Frequency (Hz)
Figure 24. Gain Control Pulse Response
Figure 23. Gain Control Frequency Response
20
2.0
10
1.8
VG = +2V
-10
VO = 2VPP
-20
-30
-40
-50
-60
Input Referred
10MHz
1.6
Group Delay (ns)
Normalized Gain (dB)
0
VG = 0V
1.4
1.2
1.0
1MHz
0.8
20MHz
0.6
-70
0.4
-80
0.2
0
-90
1M
10M
0
1G
100M
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Frequency (Hz)
Figure 26. Group Delay vs Gain Control Voltage
Figure 25. Fully-Attenuated Response
1.6
100
1.2
1.0
RS (W)
Group Delay (ns)
1.4
0.8
10
0.6
0.4
VG = +2V
VO = 1VPP
0.2
0.1dB Flatness Targeted
0
1
0
20
40
60
80
100
1
10
100
1k
Frequency (MHz)
Capacitive Load (pF)
Figure 27. Group Delay vs Frequency
Figure 28. Recommended RS vs Capacitive Load
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Typical Characteristics: VS = ±5 V, AVMAX = 6 dB (continued)
9
VO = 0.5VPP
Output Voltage Noise Density (nV/ÖHz)
At TA = 25°C, RL = 100 Ω, RF = 453 Ω, RG = 453 Ω, VG = 2 V, VIN = single-ended input on +VIN with –VIN at ground, and SOIC
package, unless otherwise noted.
CL = 10pF
6
CL = 22pF
CL = 100pF
RS (W)
3
CL = 47pF
0
RF
-3
VIN
+
RS
VCA821
-6
VOUT
CL
-
(1)
1kW
NOTE: (1) 1kW is optional.
200
VG = +1V
100
VG = +2V
VG = 0V
10
-9
1
10
100
100
1k
1k
10k
100k
1M
Capacitive Load (pF)
Frequency (Hz)
Figure 29. Frequency Response vs Capacitive Load
Figure 30. Output Voltage Noise Density
10M
Input Voltage Noise Density (pA/ÖHz)
10
1
100
1k
10k
100k
1M
10M
Frequency (Hz)
Figure 31. Input Current Noise Density
14
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
7.9 Typical Characteristics: VS = ±5 V, AVMAX = 20 dB
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 80 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
3
3
0
VG = +1V
Normalized Gain (dB)
Normalized Gain (dB)
0
-3
-6
VG = +2V
-9
-12
AVMAX = 20dB
VIN = 200mVPP
RL = 100W
-15
-18
VO = 1VPP
-3
VO = 2VPP
-6
-9
VO = 4VPP
-12
VO = 5VPP
-15
-18
1M
10M
100M
1G
1M
10M
Frequency (Hz)
200
2
100
0
-100
1
0
-1
-2
VIN = 50mVPP
VIN = 400mVPP
f = 20MHz
f = 20MHz
-3
-300
Time (10ns/div)
Time (10ns/div)
Figure 35. Large-Signal Pulse Response
0.20
0.1
Magnitude (dB)
Left Scale
-0.1
0.10
-0.2
0.05
0
-0.3
Right Scale
-0.05
-0.4
-0.10
AVMAX = 20dB
VG = +2V
-0.6
0
50
-0.15
100
150
200
Deviation from Linear Phase (°)
0.15
0
Output Voltage Noise Density (nV/ÖHz)
Figure 34. Small-Signal Pulse Response
-0.5
1G
Figure 33. Large-Signal Frequency Response
3
Output Voltage (V)
Output Voltage (mV)
Figure 32. Small-Signal Frequency Response
300
-200
100M
Frequency (Hz)
200
VG = +2V
100
VG = 0V
VG = +1V
10
100
1k
10k
100k
1M
10M
Frequency (Hz)
Frequency (MHz)
Figure 36. Gain Flatness, Deviation From Linear Phase
Figure 37. Output Voltage Noise Density
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Typical Characteristics: VS = ±5 V, AVMAX = 20 dB (continued)
-50
-66
-55
-68
Harmonic Distortion (dBc)
Harmonic Distortion (dBc)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 80 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
-60
3rd Harmonic
-65
-70
-75
AVMAX = 20dB
VG = +2V
VO = 2VPP
RL = 100W
2nd Harmonic
-80
-85
0.1
1
10
-70
AVMAX = 20dB
VG = +2V
VO = 1VPP
f = 20MHz
-72
3rd Harmonic
-74
-76
-78
2nd Harmonic
-80
100
100
1k
Frequency (MHz)
Resistance (W)
Figure 38. Harmonic Distortion vs Frequency
AVMAX = +10V/V
VG = +2V
RL = 100W
f = 20MHz
Harmonic Distortion (dBc)
-30
-40
Figure 39. Harmonic Distortion vs Load Resistance
-10
Maximum Current
Through RG Limited
-50
-60
2nd Harmonic
-70
3rd Harmonic
-80
AVMAX = 20dB
VO = 2VPP
RL = 100W
f = 20MHz
-20
Harmonic Distortion (dBc)
-20
-30
-40
Maximum Current through
RG Limited.
-50
-60
2nd Harmonic
-70
3rd Harmonic
-80
-90
-90
0.1
1
0.6
10
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Output Voltage Swing (VPP)
Figure 41. Harmonic Distortion vs Gain Control Voltage
Figure 40. Harmonic Distortion vs Output Voltage
37
40
35
35
Intercept Point (+dBm)
Intercept Point (+dBm)
Constant Input Voltage
33
31
29
VG = +2V
At 50W Matched Load
30
25
20
15
27
0
10
20
30
40
50
60
70
80
90
100
Constant Output Voltage
f = 20MHz
At 50W Matched Load
0.8
Frequency (MHz)
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Figure 42. Two-Tone, Third-Order
Intermodulation Intercept
16
1.0
Figure 43. Two-Tone, Third-Order Intermodulation Intercept
vs Gain Control Voltage
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Typical Characteristics: VS = ±5 V, AVMAX = 20 dB (continued)
11
10
3
9
8
7
0
Normalized Gain (dB)
Gain (V/V)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 80 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
6
5
4
3
2
1
-3
-6
-9
-12
0
-1
VG = 1VDC + 10mVPP
VIN = 0.1VDC
-15
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
1M
2.0
10M
Figure 44. Gain vs Gain Control Voltage
Figure 45. Gain Control Frequency Response
3
2
Input Voltage (V)
1
2.5
0
2.0
-1
4
3
Output Voltage (V)
VIN = 0.2VDC
5
Output Voltage (V)
4
1.5
1.0
1W Internal
Power
Dissipation
2
1
50W
Load
0
25W
Load
-1
-2
1W Internal
Power
Dissipation
-4
0
-5
-150
-0.5
Time (10ns/div)
-100
-50
0
VG = +2V
0.3
VO = 2VPP
-20
-30
-40
-50
-60
Input Referred
-70
150
AVMAX = +10V/V
VG = 0.7V
Input Voltage
Left Scale
2.0
1.5
0.2
1.0
0.1
0.5
0
-0.1
0
Output Voltage
Right Scale
-0.5
-0.2
-1.0
-0.3
-1.5
Output Voltage (V)
Input Voltage (V)
0
-10
100
Figure 47. Output Voltage and Current Limitations
0.4
30
10
50
Output Current (mA)
Figure 46. Gain Control Pulse Response
Normalized Gain (dB)
100W
Load
-3
0.5
20
1G
100M
Frequency (Hz)
Gain Control Voltage (V)
VG = 0V
-80
-90
1M
10M
1G
100M
-0.4
-2.0
Time (40ns/div)
Frequency (Hz)
Figure 48. Fully-Attenuated Response
Figure 49. IRG Limited Overdrive Recovery
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Typical Characteristics: VS = ±5 V, AVMAX = 20 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 80 Ω, VG = +2 V, and VIN = single-ended input on +VIN with –VIN at ground,
unless otherwise noted.
Output Voltage
Right Scale
6
1.65
4
1.60
10MHz
0.2
2
0
0
-0.2
-2
Output Voltage (V)
Input Voltage (V)
0.4
AVMAX = +10V/V
VG = +2V
Group Delay (ns)
0.6
1.55
1MHz
1.50
20MHz
1.45
-0.4
Input Voltage
Left Scale
-4
1.40
-0.6
0
-6
0.2
0.4
Time (40ns/div)
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Figure 50. Output Limited Overdrive Recovery
Figure 51. Group Delay vs Gain Control Voltage
1.8
1.6
Group Delay (ns)
1.4
1.2
1.0
0.8
0.6
0.4
VG = +2V
VO = 1VPP
0.2
0
0
20
40
60
80
100
Frequency (MHz)
Figure 52. Group Delay vs Frequency
18
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
7.10 Typical Characteristics: VS = ±5 V, AVMAX = 32 dB
3
3
0
0
Normalized Gain (dB)
Normalized Gain (dB)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 18 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SOIC package, unless otherwise noted.
-3
VG = +1V
-6
VG = +2V
-9
-12
AVMAX = 32dB
VIN = 50mVPP
RL = 100W
-15
-18
VO = 1VPP, 2VPP, 4VPP, 5VPP
-3
-6
-9
-12
-15
-18
1M
10M
100M
0
1G
100
200
300
400
500
Frequency (MHz)
Frequency (Hz)
Figure 53. Small-Signal Frequency Response
Figure 54. Large-Signal Frequency Response
400
2.5
2.0
300
Output Voltage (V)
Output Voltage (V)
1.5
200
100
0
-100
1.0
0.5
0
-0.5
-1.0
-1.5
-200
VIN = 12.5mVPP
-2.0
f = 20MHz
-300
VIN = 100mVPP
f = 20MHz
-2.5
Time (10ns/div)
Time (10ns/div)
0.15
0.2
0.10
0.05
0
0
-0.1
-0.2
-0.05
-0.3
-0.10
-0.4
-0.15
-0.20
-0.5
0
20
40
60
200
Deviation from Linear Phase (°)
AVMAX = 32dB
VG = +2V
0.1
Magnitude (dB)
Figure 56. Large-Signal Pulse response
Output Voltage Noise Density (nV/ÖHz)
Figure 55. Small-Signal Pulse Response
1000
VG = +2V
VG = +1V
100
VG = 0V
10
100
1k
10k
100k
1M
10M
Frequency (Hz)
Frequency (MHz)
Figure 57. Gain Flatness, Deviation From Linear Phase
Figure 58. Output Voltage Noise Density
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Typical Characteristics: VS = ±5 V, AVMAX = 32 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 18 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SOIC package, unless otherwise noted.
-35
-45
-55
Harmonic Distortion (dBc)
-40
Harmonic Distortion (dBc)
-50
AVMAX = 32dB
VG = +2V
VO = 2VPP
RL = 100W
-50
-55
-60
2nd Harmonic
-65
-60
-70
-75
-80
3rd Harmonic
-70
-85
0.1
1
10
3rd Harmonic
-65
100
AVMAX = 32dB
VG = +2V
VO = 1VPP
f = 20MHz
2nd Harmonic
100
1k
Frequency (MHz)
Resistance (W)
Figure 59. Harmonic Distortion vs Frequency
AVMAX = 32dB
VG = +2V
RL = 100W
f = 20MHz
Harmonic Distortion (dBc)
-20
-30
Figure 60. Harmonic Distortion vs Load Resistance
-10
Maximum Current
Through RG Limited
-40
-50
AVMAX = 32dB
VO = 2VPP
RL = 100W
f = 20MHz
-15
Harmonic Distortion (dBc)
-10
2nd Harmonic
-60
3rd Harmonic
-70
-20
-25
-30
Maximum Current Through RG Limited
-35
-40
-45
3rd Harmonic
-50
-55
2nd Harmonic
-60
-80
0.1
1
0.6
10
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Output Voltage Swing (VPP)
Figure 62. Harmonic Distortion vs Gain Control Voltage
Figure 61. Harmonic Distortion Output Voltage
35
34
Constant Output Voltage
Intercept Point (+dBm)
Intercept Point (+dBm)
32
30
28
26
24
VG = +2V
At 50W Matched Load
22
0
10
20
30
40
30
Constant Input Voltage
25
20
15
10
50
60
70
80
90
100
f = 20MHz
At 50W Matched Load
0.8
Frequency (MHz)
1.2
1.4
1.6
1.8
2.0
Gain Control Voltage (V)
Figure 63. Two-Tone, Third-Order
Intermodulation Intercept
20
1.0
Figure 64. Two-Tone, Third-Order Intermodulation Intercept
vs Gain Control Voltage
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SBOS407D – DECEMBER 2007 – REVISED MAY 2016
Typical Characteristics: VS = ±5 V, AVMAX = 32 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 18 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SOIC package, unless otherwise noted.
3
45
40
0
Normalized Gain (dB)
35
Gain (V/V)
30
25
20
15
10
-3
-6
-9
-12
5
-15
0
VG = 1VDC + 10mVPP
VIN = 10mVDC
-18
-5
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
10M
1M
Gain Control Voltage (V)
Figure 65. Gain vs Gain Control Voltage
Figure 66. Gain Control Frequency Response
Output Voltage (V)
3
2
Input Voltage (V)
1
2.5
0
2.0
-1
20
VG = +2V
10
Normalized Gain (dB)
VIN = 50mVDC
1.5
1.0
0
-10
VO = 2VPP
-20
-30
-40
-50
-60
Input Referred
-70
0.5
VG = 0V
-80
0
-90
1M
-0.5
Time (10ns/div)
0.4
1G
0.3
1.2
0.1
0.4
0
0
-0.1
-0.4
-0.2
-0.8
Output Voltage
Right Scale
-1.2
-0.4
-1.6
Output Voltage
Right Scale
0.2
Input Voltage (V)
0.8
6
AVMAX = 32dB
VG = +2V
4
0.1
2
0
0
-0.1
-2
Input Voltage
Left Scale
-0.2
-0.3
Output Voltage (V)
0.2
Output Voltage (V)
Input Voltage (V)
100M
Figure 68. Fully Attenuated Response
1.6
AVMAX = 32dB
VG = 0.7V
Input Voltage
Left Scale
10M
Frequency (Hz)
Figure 67. Gain Control Pulse Response
-0.3
1G
30
4
0.3
100M
Frequency (Hz)
-4
-6
Time (40ns/div)
Time (40ns/div)
Figure 69. IRG Limited Overdrive Recovery
Figure 70. Output Limited Overdrive Recovery
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Typical Characteristics: VS = ±5 V, AVMAX = 32 dB (continued)
At TA = +25°C, RL = 100 Ω, RF = 402 Ω, RG = 18 Ω, VG = +2 V, VIN = single-ended input on +VIN with –VIN at ground, and
SOIC package, unless otherwise noted.
2.5
2.15
10MHz
2.10
2.0
Group Delay (ns)
Group Delay (ns)
20MHz
2.05
2.00
1MHz
1.95
1.90
1.5
1.0
0.5
VG = +2V
VO = 1VPP
1.85
0
1.80
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0
2.0
20
40
60
80
100
Frequency (MHz)
Gain Control Voltage (V)
Figure 72. Group Delay vs Frequency
Figure 71. Group Delay vs
Gain Control Voltage
8 Parameter Measurement Information
+VIN
VIN
R1
50W
Source
RF
RG+
50W
RG
VOUT
RGR3
R2
50W
Load
-VIN
50W
VG
Figure 73. Test Circuit
22
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9 Detailed Description
9.1 Overview
The VCA821 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 VCA821 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 V 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 VCA821 contains a high speed, high current output buffer. The output stage can typically swing ±3.9
V and source/sink ±90 mA. The VCA821 can be operated over a voltage range of ±3.5 V to ±6 V.
9.2 Feature Description
The VCA821 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 320 MHz and a slew
rate of 2500 V/us the VCA821 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 VCA821 offers gain accuracy of ±0.3 dB.
9.3 Device Functional Modes
The VCA821 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 Figure 73. 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.
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Device Functional Modes (continued)
9.3.1 Maximum Gain of Operation
This section describes the use of the VCA821 device in a fixed-gain application in which the VG control pin is set
at VG = +1 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
VCA821 device, the RG resistor must be set so 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 table and must follow
Equation 1.
VOUT
IRG =
AVMAX ´ RG
(1)
As Equation 1 illustrates, when the output dynamic range and maximum gain are defined, the gain resistor is set.
This gain setting in turn affects the bandwidth because 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
VCA821 device is a current-feedback amplifier, the larger the feedback element, the lower the bandwidth
because 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.
9.3.2 Output Current and Voltage
The VCA821 device 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 ±90 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 47) in the Typical Characteristics: VS
= ±5 V, AVMAX = 20 dB. The X- and Y-axes of this graph show the zero-voltage output current limit and the zerocurrent output voltage limit, respectively. The four quadrants give a more detailed view of the VCA821 device
output drive capabilities, noting that the graph is bounded by a aafe operating area of 1-W maximum internal
power dissipation. Superimposing resistor load lines onto the plot shows that the VCA821 device 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 table. As the output transistors deliver power, the respective junction
temperatures increase, thereby increasing the available output voltage swing and output current.
In steady-state operation, the available output voltage and current are always greater than the temperature
shown in the over-temperature specifications because the output stage junction temperatures are higher than the
specified operating ambient.
9.3.3 Input Voltage Dynamic Range
The VCA821 device 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 VCA821 device 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
(3.2VPP) and the current (IRQ) must flow through the gain resistor, ±2.6 mA (5.2mAPP). This configuration sets a
minimum value for RE such that the gain resistor must be greater than Equation 3.
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Device Functional Modes (continued)
RGMIN =
3.2VPP
= 615.4W
5.2mAPP
(3)
Values lower than 615.4 Ω 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 limits the performance of the
circuit, the input stage of the VCA821 device goes into overdrive, resulting in limited output voltage range. Such
IRG-limited overdrive conditions are shown in Figure 49 for the gain of 20 dB and Figure 69 for the 32-dB gain.
9.3.4 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 VCA821 device can encounter. For these limitations, careful
analysis must be done to avoid input stage limitation: either voltage or IRG current.
NOTE
If control pin VG varies, the gain limitation may affect other aspects of the circuit.
9.3.5 Bandwidth
The output stage of the VCA821 device is a wideband current-feedback amplifier. As such, the 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, reduces the gain adjust range. For a given gain, reducing
the gain element limits the maximum achievable output voltage swing.
9.3.6 Offset Adjustment
As a result of the internal architecture used on the VCA821 device, the output offset voltage originates from the
output stage and from the input stage and multiplier core. Figure 74 shows 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 = –1 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.
+5V
Output Stage Offset
Compensation Circuit
10kW
4kW
0.1mF
-5V
RF
VIN
+VIN
RG+
50W
RG
FB
VOUT
VCA821
RG-VIN
+5V
1kW
50W
10kW
0.1mF
-5V
Input Stage and Multiplexer Core
Offset Compensation Circuit
Figure 74. Adjusting the Input and Output Voltage Sources
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Device Functional Modes (continued)
9.3.7 Noise
The VCA821 device offers 6 nV/√Hz input-referred voltage noise density at a gain of 20 dB and 2.6 pA/√Hz
input-referred current noise density. The input-referred voltage noise density considers that all noise terms
(except the input current noise 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 88.
eO = AVMAX ´
2 ´ (RS ´ in)2 + en2 + 2 ´ 4kTRS
(4)
A more complete model is shown in Figure 89. 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.
9.3.7.1 Input and ESD Protection
The VCA821 device 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 Absolute Maximum Ratings table.
All pins on the VCA821 device are internally protected from ESD by means of a pair of back-to-back reversebiased diodes to either power supply, as shown in Figure 75. These diodes begin to conduct when the pin
voltage exceeds either power supply by about 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 75. Internal ESD Protection
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10 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.
10.1 Application Information
The VCA821 has flexible maximum gain which is set by the Rf and Rg resistors shown in Figure 73. 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.
10.1.1 Design-In Tools
10.1.1.1 Demonstration Boards
Two printed circuit boards (PCBs) are available to assist in the initial evaluation of circuit performance using the
VCA821 device in the two package options. Both of these are offered free of charge as unpopulated PCBs that
are delivered with a user's guide. The summary information for these fixtures is shown in Table 1.
Table 1. EVM Ordering Information
PRODUCT
PACKAGE
BOARD PART NUMBER
LITERATURE NUMBER
VCA821ID
SOIC-14
DEM-VCA-SO-1B
SBOU050
VCA821IDGS
VSSOP-10
DEM-VCA-VSSOP-1A
SBOU051
The demonstration fixtures can be requested at the Texas Instruments web site (www.ti.com) through the
VCA821 device product folder.
10.1.1.2 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 VCA821 device
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.
10.1.1.3 Operating Suggestions
Operating the VCA821 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 as much ground as possible to describe the VCA821 operation.
There are four sections in the Typical Characteristics:
• VS = ±5 V DC Parameters and VS = ±5V DC and Power-Supply Parameters, which include DC operation and
the intrinsic limitation of a VCA821 device design
• VS = ±5 V, AVMAX = 6 dB Gain of 6dB Operation
• VS = ±5 V, AVMAX = 20 dB Gain of 20dB Operation
• VS = ±5 V, AVMAX = 32 dB Gain of 32dB 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)
10.1.1.4 Package Considerations
The VCA821 device is available in both SOIC-14 and VSSOP-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 76 shows a test gain circuit for the VCA821 device. Table 2 lists the recommended configuration for the
SOIC-14 and VSSOP-10 packages.
+VIN
VIN
R1
RF
RG+
50W
Source
50W
RG
VOUT
RG-
50W
Load
R3
-VIN
R2
50W
VG
Figure 76. Test Circuit
Table 2. SOIC-14 and VSSOP-10 RF and RG Configurations
G=2
G = 10
G = 40
RF
453 Ω
402 Ω
402 Ω
RG
453 Ω
80 Ω
18 Ω
There are no differences between the packages in the recommended values for the gain and feedback resistors.
However, the bandwidth for the VCA821IDGS (VSSOP-10 package) is lower than the bandwidth for the
VCA821ID (SOIC-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 77 and Figure 78.
NOTE
The scale must be changed to a linear scale to view the details.
3
3
AVMAX = 2V/V
AVMAX = 2V/V
0
AVMAX = 5V/V
Normalized Gain (dB)
Normalized Gain (dB)
0
-3
-6
-9
AVMAX = 10V/V
-12
AVMAX = 5V/V
-3
-6
-9
AVMAX = 10V/V
-12
AVMAX = 20V/V
AVMAX = 20V/V
-15
-15
AVMAX = 40V/V
AVMAX = 40V/V
-18
-18
0
28
200
400
600
800
1000
0
200
400
600
800
1000
Frequency (MHz)
Frequency (MHz)
Figure 77. SOIC-14 Recommended RF and RG vs AVMAX
Figure 78. VSSOP-10 Recommended RF and RG vs AVMAX
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10.2 Typical Applications
10.2.1 Wideband Variable-Gain Amplifier Operation Application
®
0.1mF
X2Y Capacitor Detail
®
+5V
X2Y
Capacitor
(see detail)
+VS
–5V
A
G1
+
2.2mF
VG
B
–VS
+VIN
VIN
20W
x1
FB
IRG
RG+
RG
200W
G2
+ 2.2mF
RF
1kW
x2
RG–
VOUT
VOUT
x1
20W
–VIN
VREF
SO-14
VCA821
20W
Copyright © 2016, Texas Instruments Incorporated
Figure 79. DC-Coupled, AVMAX = 20 dB, Bipolar Supply Specification and Test Circuit
10.2.1.1 Design Requirements
The design shown in Figure 79 requires 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.
10.2.1.2 Detailed Design Procedure
The VCA821 device 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 VCA821 device 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, 2500 V/μs. This exceptional full-power performance
comes at the price of relatively high quiescent current (34 mA), but low input voltage noise for this type of
architecture (6 nV/√Hz).
Figure 79 shows the DC-coupled, gain of +10 V/V, dual power-supply circuit used as the basis of the ±5-V
Electrical Characteristics and Typical Characteristics. 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 Electrical Characteristics 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 79, the total effective load is 100 Ω ∥ 1 kΩ.
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Typical Applications (continued)
NOTE
For the SOIC-14 package, there is a voltage reference pin, VREF (pin 9). For the SOIC-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 VSSOP-10 package, this pin is internally
connected 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) enables the VCA821 device to achieve the low second-harmonic distortion reported in the
Electrical Characteristics table. More information on how the VCA821 device operates can be found in the
Operating Suggestions section.
10.2.1.3 Application Curve
3
VO = 1VPP
Normalized Gain (dB)
0
VO = 2VPP
-3
-6
VO = 4VPP
-9
-12
VO = 5VPP
-15
-18
1M
10M
100M
1G
2G
Frequency (Hz)
Figure 80. Large-Signal Frequency Response
10.2.2 Difference Amplifier Application
RF
VIN+
+VIN
RG+
RS
RG
FB
VCA821
RG–
–VIN
VIN–
RS
20W
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Figure 81. Difference Amplifier
10.2.2.1 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 82.
10.2.2.2 Detailed Design Procedure
Because both inputs of the VCA821 device are high-impedance, a difference amplifier can be implemented
without any major problem. Figure 81 shows this implementation. 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.
30
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Typical Applications (continued)
NOTE
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.
Figure 82 shows the common-mode rejection ratio for this circuit implemented in a gain of 20 dB for VG = +2 V.
NOTE
Because the gain control voltage is fixed and is normally set to +2 V, the feedback
element can be reduced to increase the bandwidth. When reducing the feedback element,
make sure that the VCA821 device is not limited by common-mode input voltage, the
current flowing through RG, or any other limitation described in this data sheet.
10.2.2.3 Application Curve
Common-Mode Rejection Ratio (dB)
85
80
Input Referred
75
70
65
60
55
50
45
40
10k
100k
1M
10M
100M
Frequency (Hz)
Figure 82. Common-Mode Rejection Ratio
10.2.3 Differential Equalizer Application
VIN1
RF
+VIN
RG+
RS
R1
FB
RG
VCA821
C1
RG–
VIN2
–VIN
20W
RS
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Figure 83. Differential Equalizer
10.2.3.1 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 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 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 84.
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Typical Applications (continued)
10.2.3.2 Detailed Design Procedure
If the application requires frequency shaping (the transition from one gain to another), the VCA821 device can be
used advantageously because its architecture allows the application to isolate the input from the gain setting
elements. Figure 83 shows an implementation of such a configuration. The transfer function is shown in
Equation 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 VCA821 device to operate at a gain of +2 V/V (which gives RF = RG = 453 Ω) allows the user to
select C1 = 15.5 pF to ensure a positive value for the resistor R1. With all these values known, to achieve greater
than 300-MHz bandwidth, R1 can be calculated to be 20 Ω. Figure 84 shows the frequency response for both the
initial, unequalized frequency response and the resulting equalized frequency response.
RF
1 + sRGC1
´
G=2´
RG
1 + sR1C1
(5)
10.2.3.3 Application Curve
9
Equalized Frequency Response
6
3
Gain (dB)
0
Initial Frequency Response
of the VCA821 with RC Load
-3
-6
-9
-12
-15
-18
-21
-24
1M
10M
100M
1G
Frequency (Hz)
Figure 84. Differential Equalization of an RC Load
10.2.4 Differential Cable Equalizer Application
VIN
R2
1.33kW
+VIN
R8
50W
RG+
R18
40kW
R17
17.5kW
R21
8.7kW
R9
1.27kW
R9
1.27kW
C7
100nF
VCA821
RG–
–VIN
C6
120nF
FB
VREF
GND
VG
R1
20W
VOUT
R10
75W
VOUT
75W Load
R5
50W
C5
1.42pF
VG = +1VDC
C9
10mF
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Figure 85. Differential Cable Equalizer
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Typical Applications (continued)
10.2.4.1 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 85 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 83, but is much more accurate in replicating the 1/(sqrt(f)) frequency response shape.
10.2.4.2 Detailed Design Procedure
A differential cable equalizer can easily be implemented using the VCA821 device. An example of a cable
equalization for 100 feet of Belden cable 1694F is illustrated in Figure 84, with Figure 86 showing the result for
this implementation. This implementation has a maximum error of 0.2 dB from DC to 70 MHz.
NOTE
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 VCA821 device matches the cable attenuation.
The circuit in Figure 85 is a driver circuit. To implement a receiver circuit, the signal is received differentially
between the +VIN and –VIN inputs.
10.2.4.3 Application Curve
1694F Cable Attenuation (dB)
Equalizer Gain (dB)
2.0
1.5
1.0
Cable Attenuation
0.5
VCA821 Equalization
0
-0.5
-1.0
1
10
100
Frequency (MHz)
Figure 86. Cable Attenuation vs Equalizer Gain
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Typical Applications (continued)
10.2.5 AGC Loop Application
1kW
VIN
+VIN
RG+ FB
50W
200W
50W
VCA821 Out
RG– VG
–VIN
50W
VOUT
OPA695
50W
950W
100W
50W
0.1mF
1kW
1N4150
OPA820
VREF
Copyright © 2016, Texas Instruments Incorporated
Figure 87. AGC Loop
10.2.5.1 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.
10.2.5.2 Detailed Design Procedure
In the typical AGC loop shown in Figure 87, the OPA695 device follows the VCA821 device to provide 40 dB of
overall gain. The output of the OPA695 device is rectified and integrated by an OPA820 device to control the
gain of the VCA821 device. 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.
10.3 System Examples
RF
in
RS
+VIN
RG+
eO
RG
*
FB
VCA821
eO
RG–
–VIN
4kTRS
in
RS
*
4kTRS
NOTE: RF and RG are noiseless.
Copyright © 2016, Texas Instruments Incorporated
Figure 88. Simple Noise Model
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System Examples (continued)
VG
VG
inINPUT
+VIN
V+
RS1
*
*
enINPUT
4kTRS1
FB
x1
RF
+RG
*
inINPUT
VOUT
RG
(Noiseless)
ICORE
eO
iinOUTPUT
–RG
VREF
x1
RF
enOUTPUT
–VIN
V–
RS2
4kTRF
*
*
iniOUTPUT
enINPUT
*
4kTRF
inINPUT
GND
*
4kTRS2
Copyright © 2016, Texas Instruments Incorporated
Figure 89. Full Noise Model
11 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.
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12 Layout
12.1 Layout Guidelines
Achieving optimum performance with a high-frequency amplifier such as the VCA821 device requires careful
attention to printed circuit board (PCB) layout parasitics and external component types. Recommendations to
optimize performance include the following:
1. Minimize parasitic capacitance to any AC ground for all of the signal I/O pins. This recommendation
includes GND (pin 2). Parasitic capacitance on the output can cause instability on both the inverting input
and the noninverting input, and it can react with the source impedance to cause unintentional band limiting.
To reduce unwanted capacitance, a window around the signal I/O pins must be opened in all of the ground
and power planes around those pins. Otherwise, ground and power planes must 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.
2. Minimize the distance (less than 0.25 inches, or 6.3 mm) from the power-supply pins to high-frequency 0.1μF decoupling capacitors. At the device pins, the ground and power plane layout must 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 must always be decoupled with these
capacitors. Larger decoupling capacitors (2.2 μF to 6.8 μF), effective at lower frequencies, must also be used
on the main supply pins. These capacitors can be placed somewhat farther from the device and may be
shared among several devices in the same area of the PCB.
3. Careful selection and placement of external components preserves the high-frequency performance of the
VCA821 device. Resistors must 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 noninverting input termination resistors, must also be placed close
to the package.
4. 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) must be used,
preferably with ground and power planes opened up around them.
5. Socketing a high-speed part like the VCA821 device 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 VCA821 device onto the board.
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12.2 Layout Example
Figure 90. Layout Recommendations
12.3 Thermal Considerations
The VCA821 device does not require heat sinking or airflow in most applications. The maximum desired junction
temperature sets the maximum allowed internal power dissipation as described in this section. The maximum
junction temperature must not 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 = VS 2 / (4 × RL), where RL
is the resistive load.
NOTE
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 VCA821ID (SOIC-14 package) in the circuit of
Figure 79 operating at maximum gain and at the maximum specified ambient temperature of 85°C.
2
PD = 10V(36mA) + 5 /(4 ´ 100W) = 422.5mW
(7)
Maximum TJ = +85°C + (0.443W ´ 80°C/W) = 120.5°C
(8)
This maximum operating junction temperature is well below most system level targets. Most applications must 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 VCA821 device.
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13 Device and Documentation Support
13.1 Device Support
13.1.1 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.
13.2 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.
13.3 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.
13.4 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.
13.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
14 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)
VCA821ID
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
VCA821ID
VCA821IDGST
ACTIVE
VSSOP
DGS
10
250
RoHS & Green
NIPDAUAG
Level-2-260C-1 YEAR
-40 to 85
BOR
VCA821IDR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
VCA821ID
(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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