VCA821 VC A8 21 VC A821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 Ultra-Wideband, > 40dB Gain Adjust Range, Linear in dB VARIABLE GAIN AMPLIFIER FEATURES 1 DESCRIPTION • 710MHz SMALL-SIGNAL BANDWIDTH (G = +2V/V) • 320MHz, 4VPP BANDWIDTH (G = +10V/V) • 0.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com 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.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ELECTRICAL CHARACTERISTICS: VS = ±5V At AVMAX = 20dB, RF = 402Ω, RG = 80Ω, RL = 100Ω, unless otherwise noted.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com ELECTRICAL CHARACTERISTICS: VS = ±5V (continued) At AVMAX = 20dB, RF = 402Ω, RG = 80Ω, RL = 100Ω, unless otherwise noted.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, DC Parameters At TA = +25°C, RL = 100Ω, VG = +2V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted. MAXIMUM DIFFERENTIAL INPUT VOLTAGE vs RG MAXIMUM GAIN ADJUST RANGE vs RF 40 IRG MAX = 2.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, DC and Power-Supply Parameters At TA = +25°C, RL = 100Ω, VG = +2V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 6dB At TA = +25°C, RL = 100Ω, RF = 453Ω, RG = 453Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 6dB (continued) At TA = +25°C, RL = 100Ω, RF = 453Ω, RG = 453Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 6dB (continued) At TA = +25°C, RL = 100Ω, RF = 453Ω, RG = 453Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted. GAIN vs GAIN CONTROL VOLTAGE GAIN CONTROL FREQUENCY RESPONSE 2.2 3 2.0 1.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 6dB (continued) At TA = +25°C, RL = 100Ω, RF = 453Ω, RG = 453Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted. RECOMMENDED RS vs CAPACITIVE LOAD FREQUENCY RESPONSE vs CAPACITIVE LOAD 9 100 VO = 0.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 20dB At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 80Ω, VG = +2V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 20dB (continued) At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 80Ω, VG = +2V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 20dB (continued) At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 80Ω, VG = +2V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 20dB (continued) At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 80Ω, VG = +2V, and VIN = single-ended input on +VIN with –VIN at ground, unless otherwise noted. OUTPUT LIMITED OVERDRIVE RECOVERY Output Voltage Right Scale 2 0 0 -0.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 32dB At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 18Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 32dB (continued) At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 18Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 32dB (continued) At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 18Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS: VS = ±5V, AVMAX = 32dB (continued) At TA = +25°C, RL = 100Ω, RF = 402Ω, RG = 18Ω, VG = +2V, VIN = single-ended input on +VIN with –VIN at ground, and SO-14 package, unless otherwise noted. GROUP DELAY vs GAIN CONTROL VOLTAGE GROUP DELAY vs FREQUENCY 2.5 2.15 10MHz 2.10 2.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 APPLICATION INFORMATION WIDEBAND VARIABLE GAIN AMPLIFIER OPERATION For test purposes, the input impedance is set to 50Ω with a resistor to ground and the output impedance is set to 50Ω with a series output resistor.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com DIFFERENCE AMPLIFIER Because both inputs of the VCA821 are high-impedance, a difference amplifier can be implemented without any major problem. Figure 75 shows this implementation. This circuit provides excellent common-mode rejection ratio (CMRR) as long as the input is within the CMRR range of –2.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 DIFFERENTIAL CABLE EQUALIZER AGC LOOP A differential cable equalizer can easily be implemented using the VCA821. An example of a cable equalization for 100 feet of Belden cable 1694F is illustrated in Figure 78, with Figure 79 showing the result for this implementation.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com 1kW VIN +VIN RG+ FB 50W 200W 50W VCA821 Out RG- VG -VIN 50W OPA695 50W VOUT 950W 100W 50W 0.1mF 1kW 1N4150 OPA820 VREF Figure 81. AGC Loop predict typical small-signal ac performance, transient steps, dc performance, and noise under a wide variety of operating conditions.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 PACKAGE CONSIDERATIONS The VCA821 is available in both SO-14 and MSOP-10 packages. Each package has, for the different gains used in the typical characteristics, different values of RF and RG in order to achieve the same performance detailed in the Electrical Characteristics table.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com MAXIMUM GAIN OF OPERATION This section describes the use of the VCA821 in a fixed-gain application in which the VG control pin is set at VG = +1V. The tradeoffs described here are with bandwidth, gain, and output voltage range.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 OUTPUT VOLTAGE DYNAMIC RANGE OFFSET ADJUSTMENT With its large output current capability and its wide output voltage swing of ±3.9V typical on 100Ω load, it is easy to forget other types of limitations that the VCA821 can encounter.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com NOISE This model is formulated in Equation 5 and Figure 86. The VCA821 offers 6nV/√Hz input-referred voltage noise density at a gain of 20dB and 2.6pA/√Hz input-referred current noise density.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 THERMAL ANALYSIS The VCA821 does not require heatsinking or airflow in most applications. The maximum desired junction temperature sets the maximum allowed internal power dissipation as described in this section. In no case should the maximum junction temperature be allowed to exceed +150°C.
VCA821 SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 ....................................................................................................................................... www.ti.com INPUT AND ESD PROTECTION The VCA821 is built using a very high-speed complementary bipolar process. The internal junction breakdown voltages are relatively low for these very small geometry devices. These breakdowns are reflected in the Section 2 table.
VCA821 www.ti.com ....................................................................................................................................... SBOS407B – DECEMBER 2007 – REVISED DECEMBER 2008 Revision History Changes from Revision A (August 2008) to Revision B ................................................................................................ Page • Revised second paragraph in Wideband Variable Gain Amplifier Operation section describing pin 9 ...............................
PACKAGE OPTION ADDENDUM www.ti.
PACKAGE OPTION ADDENDUM www.ti.com (4) 18-Oct-2013 There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device.
PACKAGE MATERIALS INFORMATION www.ti.com 19-Nov-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing VCA821IDGSR VSSOP DGS 10 VCA821IDGST VSSOP DGS VCA821IDR SOIC D SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 10 250 180.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 14 2500 330.0 16.4 6.5 9.0 2.1 8.0 16.
PACKAGE MATERIALS INFORMATION www.ti.com 19-Nov-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) VCA821IDGSR VSSOP DGS 10 2500 367.0 367.0 35.0 VCA821IDGST VSSOP DGS 10 250 210.0 185.0 35.0 VCA821IDR SOIC D 14 2500 367.0 367.0 38.
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