VCA810
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SBOS275F –JUNE 2003–REVISED DECEMBER 2010
High Gain Adjust Range, Wideband,
VARIABLE GAIN AMPLIFIER
Check for Samples: VCA810
Operating from ±5V supplies, the gain control voltage
1
FEATURES
for the VCA810 will adjust the gain from –40dB at 0V
input to +40dB at –2V input. Increasing the control
voltage above ground will attenuate the signal path to
greater than 80dB. Signal bandwidth and slew rate
remain constant over the entire gain adjust range.
This 40dB/V gain control is accurate within ±1.5dB
(±0.9dB for high grade), allowing the gain control
voltage in an AGC application to be used as a
Received Signal Strength Indicator (RSSI) with
±1.5dB accuracy.
2
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HIGH GAIN ADJUST RANGE: ±40dB
DIFFERENTIAL IN/SINGLE-ENDED OUT
LOW INPUT NOISE VOLTAGE: 2.4nV/√Hz
CONSTANT BANDWIDTH vs GAIN: 35MHz
HIGH dB/V GAIN LINEARITY: ±0.3dB
GAIN CONTROL BANDWIDTH: 25MHz
LOW OUTPUT DC ERROR: < ±40mV
HIGH OUTPUT CURRENT: ±60mA
Excellent
common-mode
common-mode
input range
rejection
at the
and
two
LOW SUPPLY CURRENT: 24.8mA
(max for −40°C to +85°C temperature range)
high-impedance inputs allow the VCA810 to provide a
differential receiver operation with gain adjust. The
output signal is referenced to ground. Zero differential
input voltage gives a 0V output with a small dc offset
error. Low input noise voltage ensures good output
SNR at the highest gain settings.
APPLICATIONS
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OPTICAL RECEIVER TIME GAIN CONTROL
SONAR SYSTEMS
VOLTAGE-TUNABLE ACTIVE FILTERS
LOG AMPLIFIERS
PULSE AMPLITUDE COMPENSATION
AGC RECEIVERS WITH RSSI
In applications where pulse edge information is
critical, and the VCA810 is being used to equalize
varying channel loss, minimal change in group delay
over gain setting will retain excellent pulse edge
information.
IMPROVED REPLACEMENT FOR VCA610
+5V
6
An improved output stage provides adequate output
current to drive the most demanding loads. While
principally intended to drive analog-to-digital
converters (ADCs) or second-stage amplifiers, the
VCA810
1
V+
8
V-
±60mA
output
current
will
easily
drive
Gain
doubly-terminated 50Ω lines or a passive post-filter
Adjust
stage over the ±1.7V output voltage range.
+
VOUT
X1
5
VCA810 RELATED PRODUCTS
2
GAIN
ADJUST
RANGE
(dB)
INPUT
NOISE
(nV/√Hz)
SIGNAL
BANDWIDTH
(MHz)
3
VC
SINGLES
DUALS
—
0 ® -2V
VCA811
80
45
45
45
45
45
2.4
1.25
1
80
80
80
40
40
30
7
-40dB ® +40dB Gain
—
—
—
—
VCA2612
VCA2613
VCA2614
VCA2616
VCA2618
-5V
3.6
3.3
5.5
DESCRIPTION
The VCA810 is a dc-coupled, wideband, continuously
variable, voltage-controlled gain amplifier. It provides
a differential input to single-ended output conversion
with a high-impedance gain control input used to vary
the gain over a –40dB to +40dB range linear in dB/V.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2003–2010, Texas Instruments Incorporated