VCA810_16 Datasheet, PDF (1/40 Pages) Texas Instruments – VCA810 High Gain Adjust Range, Wideband and Variable Gain Amplifier

Product
Folder
Sample &
Buy
Technical
Documents
Tools &
Software
Support &
Community
VCA810
SBOS275G – JUNE 2003 – REVISED DECEMBER 2015
VCA810 High Gain Adjust Range, Wideband and Variable Gain Amplifier
1 Features
•1 High Gain Adjust Range: ±40 dB
• Differential In, Single-Ended Out
• Low Input Noise Voltage: 2.4 nV/√Hz
• Constant Bandwidth vs Gain: 35 MHz
• High dB/V Gain Linearity: ±0.3 dB
• Gain Control Bandwidth: 25 MHz
• Low Output DC Error: < ±40 mV
• High Output Current: ±60 mA
• Low Supply Current: 24.8 mA
(Maximum for –40°C to 85°C Temperature Range)
2 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
3 Description
The VCA810 is a DC-coupled, wideband,
continuously variable, voltage-controlled gain
amplifier. The device provides a differential input to
single-ended output conversion with a high-
impedance gain control input used to vary the gain
over a –40-dB to 40-dB range linear in dB/V.
Operating from ±5-V supplies, the device gain control
voltage adjusts the gain from –40 dB at a 0-V input to
40 dB at a –2-V input. Increasing the control voltage
above ground attenuates the signal path to greater
than 80 dB. Signal bandwidth and slew rate remain
constant over the entire gain adjust range. This 40-
dB/V gain control is accurate within ±1.5 dB (±0.9 dB
for high grade), allowing the gain control voltage in an
AGC application to be used as a received signal
strength indicator (RSSI) with ±1.5-dB accuracy.
Excellent common-mode rejection and common-
mode input range at the two high-impedance inputs
allow the device to provide a differential receiver
operation with gain adjust. The output signal is
referenced to ground. Zero differential input voltage
gives a 0-V 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 device is being used to equalize
varying channel loss, minimal change in group delay
over gain setting retains excellent pulse edge
information.
An improved output stage provides adequate output
current to drive the most demanding loads. Although
principally intended to drive analog-to-digital
converters (ADCs) or second-stage amplifiers, the
±60-mA output current easily drives doubly-
terminated 50-Ω lines or a passive post-filter stage
over the ±1.7-V output voltage range.
PART NUMBER
VCA810
Device Information
PACKAGE
BODY SIZE (NOM)
SOIC (8)
4.90 mm × 3.91 mm
Functional Block Diagram
+5V
6
1
V+
VCA810
8
V-
Gain
Adjust
+
X1
5 ^VOUT
2
3
V_C
0 ® -2V
-40dB ® +40dB Gain
7
-5V
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.