Electrinica
ICL8013 Data Sheet April 1999 File Number 2863. 4 1 MHz, Four Quadrant Analog Multiplier The ICL8013 is a four quadrant analog multiplier whose output is proportional to the algebraic product of two input signals. Feedback around an internal op amp provides level shifting and can be used to generate division and square root functions. A simple arrangement of potentiometers may be used to trim gain accuracy, offset voltage and feedthrough performance. The high accuracy, wide bandwidth, and increased versatility of the ICL8013 make it ideal for all multiplier applications in p ontrol and instrume measuring equpmen and demodulators, amplifiers.
Features • Accuracy. Input Voltage Range Bandwidth.. 3 – tons include RMS alanced modulators oltage controlled . (“B” Version) • . ±IOV• • uses Standard 5V Supplies • Built- n Op Amp Provides Leve’ Shifting, Division and Square Root Functions Pinout ICL8013 (METAL CAN) TOP VIEW YOS IO YIN V+ 234 5 1 9 zosg 7 XIN GND XOS Ordering Information PART NUMBER ICL8013BCTX ICL8013CCTX MULTIPLICATION ERROR (MAX) TEMP. RANGE (oc) O to 70 0 to 70 PKG. NO. can 10 Pin TIO. B Metal can OUTPUT Functional Diagram
ZIN XIN XOS VOLTAGE TO CURRENT CONVERTER AND SIGNAL COMPRESSION BALANCED VARIABLE GAIN AMPLIFIER ZOS op AMP OUT YIN YOS VOLTAGE TO CURRENT CONVERTER CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 copynghtc Absolute Maximum Ratings Supply Voltage nput Vo tages (XIN, YIN, ZIN, Thermal Information Thermal Resistance (Typic ntersil Corporation 1999 XOS, YOS, ZOS) 2 3 .. VSUPPLY 9JC (oc,w) is measured With the component mounted on an evaluation PC board in free air. Electrical Specifications
TA = 250C, VSIJPPLY = ±15V, Gain and Offset Potentiometers Externally Trimmed, Unless Otherwise Specified TEST CONDITIONS ICL8013B MIN -10 «xe IO -10 < Y < 10 -10 X - -1 TYPXY 10 loz XO. 3 1. 5 ±0. 5 ±0. 2 1. 0 75045 75 51 1 0. 6 3 MAX 1. 0 100 100 MIN ICL8013C TYP XY 10 loz XO. 3 1. 5 1. 0 750 45 7551 1 0. 6 3 MAX 2. 0 200 150 % Full Scale % Full Scale mv mv % pull scale UNITS PARAMETER Multiplier Function Multiplication Error Divider Function Division Error Feedthrough Non-LineantyX nput Y Input Frequency Response Small Signal Bandwidth (-3dB) Full Power Bandwidth Slew Rate 1% Amplitude
Error 1 % Vector Error (0. 50 Phase Shift) Settling Time (to ±2% of Final value) VIN = ±IOV X = 20VP-P Y: ±IOVDC Y = 20VP-P X – ±IOVDC % % MHZ kHz WuS kHz kHz vs TIVRMS mVRMS MO overload Recovery (to of Final value) VIN = OV output Noise 5Hz to 10kHz 5Hz to 5MHz Input Resistance X Input Y Input Z Input Input Bias Current X or Y Input Z Input VIN = OVVIN = OV 10 636 30F ICL8013B MIN TYP MAX MIN ICL8013C TYP MAX UNITS PARAMETER Power Supply Variation Multiplication Error Output Offset Scale Factor Quiescent Current 0. 2 0. 1 3. 5 75 6. 0 100 6. 0 mV/V mA
THE FOLLOWING SPECIFICATIONS APPLY OVER THE OPERATING TEMPERATURE RANGES Multiplication Error Average Temp. Coefficients Accuracy Output Offset Scale Factor Input Bias Current X orY Input Z Input Input Voltage (X, Y, or Z) Output voltage swing RL 2kQ CL VIN = OV 5 25 10 35 V V 0. 06 0. 2 0. 04 0. 06 0. 2 0. 04 %/oc mwoc WOC -IOV < XIN < IOV, -IOV < YIN < 3 % Full Scale Schematic Diagram V+ R2 R8 R16 R23 Cl Q16Q17 R20 Ril R6 RI R21 Q18 RIO Q5 Q6 QII Q12 Q19 Q20 Q24 Q23 R29 Q27 yos XOS R22 Q26 Q22 R31 R30 Q21 Q25 R33 ZOS R27 ZIN QI Q2 Q7 Q8 Q14 YIN RI XIN Q3 Q4 R3 COMMON 40F utput voltage is not centered around ground.
The first problem relates to the method of converting the W voltage to a current to vary the gain of the VX differential paira A better method, Figure 3, uses another differential pair but with considerable emitter degeneration. In this circuit the differential input voltage appears across the common emitter resistor, producing a current which adds or subtracts from the quiescent current in either collector. This type of voltage to current converter handles signals from OV to ±IOV with excellent linearity.
V+IE Al AVOUT VIN = VIN RE 21EV- FIGURE 1 . DIFFERENTIAL AMPLIFIER The small signal differential voltage gain of this circuit is given by: = = -V IN rE 1 kT Substituting r E = RL V OUTAV –gM Eql V OUT -VINCI n=VlNx The output voltage is thus proportional to the product of the input voltage VIN and the emitter current IE. In the simple transconductance multiplier of Figure 2, a current source comprising Q3, Dl, and RY is used. IfVY is large compared with the drop across Dl, then WID- kTRY = 21 E andRYqRLV OUT- ——(VXXVY) FIGURE 3.
VOLTAGE TO CU 3 ERTER signal does not produce zero output voltage. The circuit whose peration is illustrated by Figures 4A, 4B, and 4C overcomes this problem and forms the heart of many multiplier circuits in use today. This circuit is basically two matched differential pairs with cross coupled collectors. Consider the case shown in Figure 4A of exactly equal current sources basing the two pairs. With a small positive signal at VIN, the collector current of QI and Q4 Will increase but the collector currents of Q2 and Q3 Will decrease by the same amount.
Since the collectors are cross coupled the current through the load resistors remains unchanged and independent of the VIN input voltage. In Figure 48, notice that with VIN = O any variation in the ratio of biasing current sources Will produce a common mode voltage across the load resistors. The differential output voltage Will remain zero. In Figure 4C we apply a differential input voltage with unbalanced current sources. If IEI is twice IE2 the gain of differential pair QI and Q2 is twice the gain of pair Q3 and Q4.
Therefore, the change In cross coupled conector currents Will be unequal and a differential output voltage Will resulta By replacing the separate biasing current sources with the voltage to current converter of Figure we have a balanced multiplier circuit capable of four quadrant operation (Figure 5). RL VOUT VIN 21E Q3 RL VOIJT K qRL kTRY(VXxVY) ID Dl 6 OF (VX x W) = kTRY (VXX WO FIGURE 2. TRANSCONDUCTANCE MULTIPLIER 4 1/1+A2E V+ IE RL 1/1-A2E + QI VIN Q2 Q3 Q4 independent of amplitude. Ifwe combine this circuit with the voltage to current converter of Figure 3, we have Figure 6B.
The output of the differential amplifier is now proportional to the input voltage over a large dynamic range, thereby improving linearity while minimizing drift and noise factors. The complete chematic is shown after the Electrical Specifications Table- The differential pair Q3 and Q4 form a voltage to current converter whose output is compressed in collector diodes QI and Q2. These diodes drive the balanced cross-coupled differential amplifier Q7/Q8 Q14/Q1 5. The gain of these amplifiers is modulated by the voltage to current converter Q9 and QIO.
Transistors Q5, Q6, QI 1, and Q12 are constant current sources which bias the voltage to current converter. The output amplifier comprises transistors Q16 through Q27. 21E FIGURE 4C. INPUT SIGNAL WI H UNBALANCED CURRENT SOURCES, DIFFERENTIAL OUTPUT VOLTAGE This circuit of Figure 5 still has the problem that the input voltage VIN must be small to keep the differential amplifier in the linear region. To be able to handle large signals, we need an amplitude compression circuit. XX ID 80F BLOCK DIAGRAM WIN XIN YIN IO ZIN VXIN YIN 3617109 ICL80134 OUTPUT – FIGURE 68.
VOLTAGE GAIN WITH SIGNAL COMPRESSION Definition of Terms Multiplication/Division Error: This is the basic accuracy specification. It includes terms due to linearity, gain, and offset errors, and is expressed as a percentage ofthe full scale output. Feedthrough: With either input at zero, the output of an ideal ultiplier should be zero regardless of the signal applied to the other input. The output seen in a non-ideal multiplier is known as the feedthrough. Nonlinearity: The maximum deviation from the best straight line constructed through the output data, expressed as a percentage of full scale.
One input is held constant and the other swept through it nominal range. The nonlinearity is the component of the total multiplication/division error which cannot be trimmed out. 7. 5K XOS YOS ZOS FIGURE 78. MULTIPLIER CIRCUIT CONNECTION Division Ifthe Z terminal is used as an input, and the output of the op mp connected to the Y input, the device functions as a divider. Since the input to the op amp is at virtual ground, and requires negligible bias current, the overall feedback forces the modulator output current to equal the current produced by Z.
N = V OUT, V OUT – loz IN RIOZ IN Since Y Applications Multiplication In the standard multiplier connection, the Z terminal is connected to the op amp output. All of the modulator output current thus flows through the feedback resistor R27 and produces a proportional output voltage. MULTIPLIER TRIMMING PROCEDURE 1. Set XIN YIN OV and adjust ZOS for zero Output. . Apply a ±IOV low frequency (SI OOHz) sweep (sine or triangle) to YIN with XIN = CV, and adjust XOS for minmum output. 3.
Apply the sweep signal of Step 2 to XIN with YIN = OV and adjust YOS for minimum Output. 4. Readjust ZOS as in Step 1, if necessary. 5. With XIN = IO. OVDC and the sweep signal of Step 2 applied to YIN, adjust the Gain potentiometer for Output = YIN. This is easlly accomplished with a differential scope plugin (A+B) by inverting one signal and adjusting Gain control for (Output – YIN) = Zero. Note that when connected as a divider, the X input must be a egative voltage to maintain overall negative feedback.
DIVIDER TRIMMING PROCEDURE 1 . Set trimming potentiometers at mid- scale by adjusting voltage on Pins 7, 9 and 10 (XOS, yos, ZOS) for OV. 2. With ZIN = OV, trim ZOS to hold the Output constant, as XIN is varied from -IOV through -IV. 3. With ZIN = OV and XIN = -IO. OV adjust YOS for zero Output voltage. 4. With ZIN XIN (and/or ZIN – -XIN) adjust XOS for minimum worst case variation of Output, as XIN is varied from -IOV to -IV. 5. Repeat Steps 2 and 3 If Step 4 required a large initial adjustment. 6. With ZIN = XIN (and/o 0 DF 13