VCA810_12 Datasheet, PDF (1/30 Pages) Texas Instruments – High Gain Adjust Range, Wideband, VARIABLE GAIN AMPLIFIER

VCA810
VCA810
www.ti.com
SBOS275F – JUNE 2003 – REVISED DECEMBER 2010
High Gain Adjust Range, Wideband,
VARIABLE GAIN AMPLIFIER
Check for Samples: VCA810
FEATURES
1
•2 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
• LOW SUPPLY CURRENT: 24.8mA
(max for −40°C to +85°C temperature range)
APPLICATIONS
• OPTICAL RECEIVER TIME GAIN CONTROL
• SONAR SYSTEMS
• VOLTAGE-TUNABLE ACTIVE FILTERS
• LOG AMPLIFIERS
• PULSE AMPLITUDE COMPENSATION
• AGC RECEIVERS WITH RSSI
• IMPROVED REPLACEMENT FOR VCA610
1
V+
8
V-
+5V
6
VCA810
Gain
Adjust
+
X1
5 ^VOUT
2
3
V_C
0 ® -2V
-40dB ® +40dB Gain
7
-5V
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.
Operating from ±5V supplies, the gain control voltage
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.
Excellent
common-mode
rejection
and
common-mode input range at the two
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.
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.
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
±60mA output current will easily drive
doubly-terminated 50Ω lines or a passive post-filter
stage over the ±1.7V output voltage range.
VCA810 RELATED PRODUCTS
SINGLES
DUALS
GAIN
ADJUST
RANGE
(dB)
INPUT
NOISE
(nV/√Hz)
SIGNAL
BANDWIDTH
(MHz)
VCA811
—
80
2.4
80
—
VCA2612
45
1.25
80
—
VCA2613
45
1
80
—
VCA2614
45
3.6
40
—
VCA2616
45
3.3
40
VCA2618
45
5.5
30
1
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Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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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.
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