VCA
261
4
VCA2614
SBOS185D 鈥?JANUARY 2001 鈥?REVISED MARCH 2003
Dual, VARIABLE GAIN AMPLIFIER
with Input Buffer
FEATURES
q
GAIN RANGE: 40dB
q
40MHz BANDWIDTH
q
LOW CROSSTALK: 70dB at Max Gain, 5MHz
q
HIGH-SPEED VARIABLE GAIN ADJUST
q
POWER SHUTDOWN MODE
q
HIGH IMPEDANCE INPUT BUFFER
DESCRIPTION
The VCA2614 is a highly integrated, dual receive channel,
Variable Gain Amplifier (VGA) with analog gain control.
The VCA2614鈥檚 VGA section consists of two parts: the Volt-
age Controlled Attenuator (VCA) and the Programmable Gain
Amplifier (PGA). The gain and gain range of the PGA can be
digitally programmed. The combination of these two program-
mable elements results in a variable gain ranging from 0dB up
to a maximum gain as defined by the user through external
connections. The single-ended unity gain input buffer provides
predictable high input impedance. The output of the VGA can
be used in either a single-ended or differential mode to drive
high-performance Analog-to-Digital Converters (ADCs). A sepa-
rate power-down pin reduces power consumption.
The VCA2614 also features low crosstalk and outstanding
distortion performance. The combination of low noise and gain
range programmability makes the VCA2614 a versatile build-
ing block in a number of applications where noise perfor-
mance is critical. The VCA2614 is available in a TQFP-32
package.
APPLICATIONS
q
ULTRASOUND SYSTEMS
q
GAMMA CAMERAS
q
WIRELESS RECEIVERS
q
TEST EQUIPMENT
C
P2A
C
P1A
VCA2614
(1 of 2 Channels)
N
OUTA
Voltage
Control
Attenuator
Programmable
Gain Amplifier
IN
A
Buffer
P
OUTA
MGS
1
VCA
CNTL
Analog
Control
Maximum Gain
Select
MGS
2
MGS
3
Maximum
Gain Select
N
OUTB
Voltage
Control
Attenuator
Programmable
Gain Amplifier
IN
B
Buffer
P
OUTB
C
P2B
C
P1B
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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.
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