Document
VCA 261 4
VCA2614
SBOS185D – JANUARY 2001 – REVISED MARCH 2003
Dual, VARIABLE GAIN AMPLIFIER with Input Buffer
FEATURES
q q q q q q GAIN RANGE: 40dB 40MHz BANDWIDTH LOW CROSSTALK: 70dB at Max Gain, 5MHz HIGH-SPEED VARIABLE GAIN ADJUST POWER SHUTDOWN MODE HIGH IMPEDANCE INPUT BUFFER
DESCRIPTION
The VCA2614 is a highly integrated, dual receive channel, Variable Gain Amplifier (VGA) with analog gain control. The VCA2614’s VGA section consists of two parts: the Voltage 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 programmable 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 separate 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 building block in a number of applications where noise performance is critical. The VCA2614 is available in a TQFP-32 package.
APPLICATIONS
q q q q ULTRASOUND SYSTEMS GAMMA CAMERAS WIRELESS RECEIVERS TEST EQUIPMENT
CP2A
CP1A
VCA2614 (1 of 2 Channels) NOUTA Voltage Control Attenuator Programmable Gain Amplifier
INA
Buffer
POUTA
MGS1 VCACNTL Analog Control Maximum Gain Select MGS2 MGS3
Maximum Gain Select
NOUTB Voltage Control Attenuator Programmable Gain Amplifier
INB
Buffer
POUTB
CP2B
CP1B
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.
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 © 2001-2003, Texas Instruments Incorporated
www.ti.com
ABSOLUTE MAXIMUM RATINGS(1)
Power Supply (+VS) ............................................................................. +6V Analog Input ............................................................. –0.3V to (+VS + 0.3V) Logic Input ............................................................... –0.3V to (+VS + 0.3V) Case Temperature ......................................................................... +100°C Junction Temperature .................................................................... +150°C Storage Temperature ...................................................... –40°C to +150°C NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. Exposure to absolute maximum conditions for extended periods may affect device reliability.
ELECTROSTATIC DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
PACKAGE/ORDERING INFORMATION
PACKAGE DESIGNATOR(1) PBS SPECIFIED TEMPERATURE RANGE –40°C to +85°C PACKAGE MARKING VCA2614Y ORDERING NUMBER VCA2614Y/250 VCA2614Y/2K TRANSPORT MEDIA, QUANTITY Tape and Reel, 250 Tape and Reel, 2000
PRODUCT VCA2614Y
PACKAGE-LEAD TQFP-32 Surface-Mount
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NOTE: (1) For the most current specifications and package information, refer to our web site at www.ti.com.
ELECTRICAL CHARACTERISTICS
At TA = +25°C, VDD = 5V, load resistance = 500Ω on each output to ground differential output (2Vp-p), MGS = 011, and fIN = 5MHz, unless otherwise noted. VCA2614Y PARAMETER BUFFER Input Resistance Input Capacitance Input Bias Current Maximum Input Voltage Input Voltage Noise Input Current Noise Noise Figure Bandwidth CONDITIONS MIN TYP 600 5 1 1 4.8 350 13 100 1 40 300 2.5 ±1 1 ±40 –60 –50 –40 to –45 5 –59 70 13 10.5 ±2(1) ±50 0.2 to 3.0 1 0.2 4.75 Operating, Each Channel 5.0 120 9.2 5.25 150 MAX UNITS kΩ pF nA Vp-p nV/ √Hz fA/ √Hz dB MHz Vp-p MHz V/µs V Ω mA dBc dBc dB ns dBc dB ns dB/V dB mV V MΩ µs V mW mW
MGS = 111, PGA Gain = 44.2dB, RS = 50Ω Independent of Gain RF = 550Ω, PGA Gain = 44.2dB, RS = 75Ω
PROGRAMMABLE VARIABLE GAIN AMPLIFIER Peak Input Voltage –3dB Bandwidth Slew Rate Output Signal Range RL ≥ 500Ω Each Side to Ground Output Impedance f = 5MHz Output Short-Circuit Current 3rd-Harmonic Distortion f = 5MHz, VOUT = 2Vp-p, VCACNTL = 3.0V 2nd-Ha.