Electronic Components Datasheet Search

Delete All
ON OFF
 ALLDATASHEET.COM Part No.DescriptionMarking X

## VCA824IDG4 Datasheet(PDF) 29 Page - Texas Instruments

 Part No. VCA824IDG4 Description Ultra-Wideband, > 40-dB Gain Adjust Range, Linear in V/V Variable Gain Amplifier Download 41 Pages Scroll/Zoom 100% Maker TI1 [Texas Instruments] Homepage http://www.ti.com Logo

## VCA824IDG4 Datasheet(HTML) 29 Page - Texas Instruments

 29 / 41 page 1.51.0-1.5Time( s)m011020.5-1.0-0.509876543VOUTVINVGf=1MHzf=0.1MHzINVGRF+VINRG+RG--VINFBRGR2R320WVINVGRSSourceImpedanceR1VCA824VCA824www.ti.comSBOS394D – NOVEMBER 2007 – REVISED JANUARY 2016Typical Application (continued)Figure 76. Four-Quadrant Multiplier CircuitFigure 77 illustrates the behavior of this circuit. Keeping the input amplitude of a 1-MHz signal constant andvarying the VG voltage (100 kHz, 2 VPP) gives the modulated output voltage shown in Figure 77.9.2.1 Design RequirementsA multiplier requires two inputs, one for the X input and one for the Y input. The output of the multiplier circuit isin the form of Vout = aVin1 × bVin2 : where a and b are real numbers and should not be negative. For fourquadrant operation both positive and negative inputs must be supported on the X and Y inputs.A four-quadrant multiplier can easily be implemented using the VCA824. By placing a resistor between FB andVIN, the transfer function depends upon both VIN and VG, as shown in Equation 109.2.2 Detailed Design ProcedureSetting R1 to equal RG, the term that depends only on VIN drops out of the equation, leaving only the term thatdepends on both VG and VIN. VOUT then follows Equation 11.The behavior of this circuit is illustrated in Figure 77. Keeping the input amplitude of a 1MHz signal constant andvarying the VG voltage (100 kHz, 2 VPP) gives the modulated output voltage shown in Figure 77.9.2.3 Application CurveFigure 77. Modulated Output Signal of the 4-Quadrant Multiplexer CircuitCopyright © 2007–2016, Texas Instruments IncorporatedSubmit Documentation Feedback29Product Folder Links: VCA824