link to page 9 link to page 13 link to page 9 link to page 9 link to page 13 link to page 9 Data SheetAD633APPLICATIONS INFORMATION The AD633 is well suited for such applications as modulation +15V and demodulation, automatic gain control, power measurement, 0.1µF voltage-controlled amplifiers, and frequency doublers. These E1X1+VS 8 applications show the pin connections for the AD633JN (8-lead RE22X2W7W =R110V PDIP), which differs from the AD633JR (8-lead SOIC). AD633JN1kΩ3Y1Z6CR2MULTIPLIER CONNECTIONS3kΩ4Y2–VS 5 Figure 12 shows the basic connections for multiplication. The X 0.1µF 013 and Y inputs normally have their negative nodes grounded, but –15V 00786- they are ful y differential, and in many applications, the grounded Figure 14. Bounceless Frequency Doubler (See the Model Results Section) inputs may be reversed (to facilitate interfacing with signals of a particular polarity while achieving some desired output polarity), At ωo = 1/CR, the X input leads the input signal by 45° (and is or both may be driven. attenuated by √2), and the Y input lags the X input by 45° (and is also attenuated by √2). Because the X and Y inputs are 90° out of +15V phase, the response of the circuit is (satisfying Equation 3) 0.1µF+1X1+VS 8 1 E E X W = sin ω t + 0 45° sin ω t + 0 45° INPUT(X1 – X2)(Y1 – Y2) (10 V) ( ) ( ) –2X2W7W =+ Z 2 2 AD633JN10V 2 +3Y1Z6OPTIONAL SUMMING E YINPUT, Z = sin 2 ω t (4) INPUT (40 V) ( 0 ) –4Y2–VS 50.1µF 1 1 0 which has no dc component. Resistor R1 and Resistor R2 are –15V 00786- included to restore the output amplitude to 10 V for an input Figure 12. Basic Multiplier Connections (See the Model Results Section) amplitude of 10 V. SQUARING AND FREQUENCY DOUBLING The amplitude of the output is only a weak function of frequency; As is shown in Figure 13, squaring of an input signal, E, is the output amplitude is 0.5% too low at ω = 0.9 ω0 and ω0 = 1.1 ω0. achieved simply by connecting the X and Y inputs in paral el to GENERATING INVERSE FUNCTIONS produce an output of E2/10 V. The input can have either polarity, but the output is positive. However, the output polarity can be Inverse functions of multiplication, such as division and square reversed by interchanging the X or Y inputs. The Z input can be rooting, can be implemented by placing a multiplier in the feedback used to add a further signal to the output. loop of an op amp. Figure 15 shows how to implement square rooting with the transfer function for the condition E < 0. +15V The 1N4148 diode is required to prevent latchup, which can 0.1µFE1X1+VS 8 occur in such applications if the input were to change polarity, E2 even momentarily. 2X2W7W =AD633JN10V3Y1Z6 W = − (10E)V (5) 4Y2–VS 510kΩ0.1µF 012 +15V+15V–15V0.01µF0.1µF 00786- 1X1+V Figure 13. Connections for Squaring S80.1µF10kΩ27X2W7 When the input is a sine wave E sin ωt, this squarer behaves as a E < 0V2AD633JN frequency doubler, because AD71163Y1Z6–15V ( 31N41484–V E sin ωt)2 4Y2 E2 S5 = (1− cos 2 ωt) (2) 0.1µF0.1µF 10 V 20 V 014 –15V Equation 2 shows a dc term at the output that varies strongly W = √ –(10V)E 000786- with the amplitude of the input, E. This can be avoided using Figure 15. Connections for Square Rooting the connections shown in Figure 14, where an RC network is used to generate two signals whose product has no dc term. It uses the identity cos θ θ 1 sin = (sin 2 θ) (3) 2 Rev. K | Page 9 of 20 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS FUNCTIONAL DESCRIPTION ERROR SOURCES APPLICATIONS INFORMATION MULTIPLIER CONNECTIONS SQUARING AND FREQUENCY DOUBLING GENERATING INVERSE FUNCTIONS VARIABLE SCALE FACTOR CURRENT OUTPUT LINEAR AMPLITUDE MODULATOR VOLTAGE-CONTROLLED, LOW-PASS AND HIGH-PASS FILTERS VOLTAGE-CONTROLLED QUADRATURE OSCILLATOR AUTOMATIC GAIN CONTROL (AGC) AMPLIFIERS MODEL RESULTS EXAMPLES OF DC, SIN, AND PULSE SOLUTIONS USING MULTISIM EXAMPLES OF DC, SIN, AND PULSE SOLUTIONS USING PSPICE EXAMPLES OF DC, SIN, AND PULSE SOLUTIONS USING SIMETRIX EVALUATION BOARD OUTLINE DIMENSIONS ORDERING GUIDE