VCA810 Datasheet, PDF (1/25 Pages) Burr-Brown (TI) – High Gain Adjust Range, Wideband, Voltage-Controlled Amplifier

VCA810
SBOS275C − JUNE 2003 − REVISED OCTOBER 2004
High Gain Adjust Range, Wideband,
Voltage-Controlled Amplifier
FEATURES
D HIGH GAIN ADJUST RANGE: +40dB
D DIFFERENTIAL IN/SINGLE-ENDED OUT
D LOW INPUT NOISE VOLTAGE: 2.4nV//Hz
D CONSTANT BANDWIDTH vs GAIN: 35MHz
D HIGH dB/V GAIN LINEARITY: +0.3dB
D GAIN CONTROL BANDWIDTH: 25MHz
D LOW OUTPUT DC ERROR: < +40mV
D HIGH OUTPUT CURRENT: +60mA
D LOW SUPPLY CURRENT: 24.8mA (max for
−405C to +855C temperature range)
APPLICATIONS
D OPTICAL RECEIVER TIME GAIN CONTROL
D SONAR SYSTEMS
D VOLTAGE-TUNABLE ACTIVE FILTERS
D LOG AMPLIFIER
D PULSE AMPLITUDE COMPENSATION
D AGC RECEIVER WITH RSSI
D IMPROVED REPLACEMENT FOR THE
VCA610
1
V+
8
V−
2
+5V
6
VCA810
G a in
Adjust
+
X1
5 ^VOUT
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 > 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 2nd-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)
VCA811
—
80
2.4
—
VCA2612
45
1.25
—
VCA2613
45
1
—
VCA2614
45
3.6
—
VCA2616
45
3.3
—
VCA2618
45
5.5
SIGNAL
BANDWIDTH
(MHz)
80
80
80
40
40
30
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.
PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright  2003−2004, Texas Instruments Incorporated
www.ti.com