MOTOROLA MC1494P Datasheet

  

The MC1494 is designed for use where the output voltage is a linear product of two input voltages. Typical applications include: multiply, divide, square root, mean square, phase detector, frequency doubler, balanced modulator/ demodulator, electronic gain control.

The MC1494 is a variable transconductance multiplier with internal level–shift circuitry and voltage regulator. Scale factor , input offsets and output offset are completely adjustable with the use of four external potentiometers. Two complementary regulated voltages are provided to simplify offset adjustment and improve power supply rejection.

• Operates with ±15 V Supplies

• Excellent Linearity: Maximum Error (X or Y) ±1.0 %

• Wide Input Voltage Range: ±10 V

• Adjustable Scale Factor, K (0.1 nominal)

• Single–Ended Output Referenced to Ground

• Simplified Offset Adjust Circuitry

• Frequency Response (3.0 dB Small–Signal): 1.0 MHz

• Power Supply Sensitivity: 30 mV/V typical

Order this document by MC1494/D



LINEAR FOUR–QUADRANT

MULTIPLIER INTEGRATED

CIRCUIT

SEMICONDUCTOR

TECHNICAL DATA

Figure 1. Multiplier Transfer Characteristic Figure 2. Linearity Error versus T emperature

8.0

6.0

4.0

2.0 0

– 2.0 – 4.0

, OUTPUT VOL TAGE (V)

– 6.0 – 8.0

–10

–10 – 8.0 – 6.0 – 4.0 – 2.0 0 2.0 4.0 6.0 8.0 10

X Y

k =

VX, INPUT VOLTAGE (V)

KXY

P SUFFIX

PLASTIC PACKAGE

CASE 648C

ORDERING INFORMATION

Tested Operating

Device

MC1494P TA = 0° to + 70°C Plastic DIP

1.00

0.75

0.50

0.25

RX RY

E or E , LINEARITY ERROR (%)

0 – 50 0 50 125

– 25 25 75 100

Temperature Range

TA, AMBIENT TEMPERATURE (°C)

Package

MOTOROLA ANALOG IC DEVICE DATA

 Motorola, Inc. 1996 Rev 0

MC1494

MAXIMUM RATINGS

Power Supply Voltages ± V ± 18 Vdc Differential Input Signal V9–V

Common Mode Input Voltage

= V9 = V

CMY

= V10 = V

CMX

Power Dissipation (Package Limitation)

TA = + 25°C

Derate above TA = + 25°C Operating Temperature Range T Storage Temperature Range T

(TA = + 25°C, unless otherwise noted.)

Rating Symbol Value Unit

±|6 + I1RY|<30

V10–V

CMY

CMX

1/θ

stg

±|6 + I1RX|<30

±11.5 ±11.5

1.25 20

0 to +70 °C

– 65 to +150 °C

mW/°C

Vdc

ELECTRICAL CHARACTERISTICS (±V = ±15 V, T

unless otherwise noted.)

Characteristics

Linearity

Output error in percent of full scale –10 V <VX < +10 V (VY = ±10 V) –10 V <VY < +10 V (VX = ±10 V) TA = +25°C TA = T

Input

Voltage Range (VX = VY = Vin) Resistance (X or Y Input) Offset Voltage (X Input) (Note 1)

(Y Input) (Note 1)

Bias Current (X or Y Input) Offset Current (X or Y Input)

Output

Voltage Swing Capability Impedance Offset Voltage (Note 1) Offset Current (Note 1)

Temperature Stability (Drift)

TA = T Output Offset (X = 0, Y = 0) Voltage

X Input Offset (Y = 0) Y Input Offset (X = 0) Scale Factor Total DC Accuracy Drift (X = 10, Y = 10)

Dynamic Response

Small Signal (3.0 dB)

Power Bandwidth (47 k) 3° Relative Phase Shift 1% Absolute Error

Common Mode

Input Swing (X or Y) Gain (X or Y)

Power Supply

Current

Quiescent Power Dissipation Sensitivity

Regulated Offset Adjust Voltages

Positive/Negative T emperature Coef ficient (VR+ or VR–) Power Supply Sensitivity (VR+ or VR–)

NOTE: 1.Offsets can be adjusted to zero with external potentiomers. T

high

or T

to T

low

(Note 1)

= + 25°C, R1 = 16 kΩ, RX = 30 kΩ, RY = 62 kΩ, RL = 47 kΩ,

Current

Figure Symbol Min Typ Max Unit

= +70°C, T

High

3 ERX or E

4, 5, 6

5, 6

–

BW BW

= 0°C

Low

iox

ioy

|Iio|

|VOO|

|IOO|

|TCVOO|

|TCIOO| |TCV

iox

|TCV

ioy

|TCK| |TCE|

3dB (X) 3dB (Y)

BW fφ

fθ

CMV A

Id+ Id– P

S+ S–

VR+, VR–

TCV

SR+, SR–

| |

– –

±10

– – – – –

±10

– – –

– – – – – –

– – – – –

±10.5

–

– – – – –

3.5 – –

±0.5

–

300

0.2

0.8

1.0 50

–

850

1.2 25

1.3 27

0.3

1.5

0.07

0.09

0.8

1.0

440 240

–

–65

6.0

6.5

185

13 30

4.3

0.03

0.6

±1.0 ±1.3

– –

2.5

400

– –

2.5 52

– – – – – –

– – – – –

– –

12 12

350 100 200

5.0

– –

MΩ

µA nA

kΩ

µA

mV/°C

nA/°C

mV/°C

%/°C

MHz

kHz

mAdc

mV/V

Vdc

mV/°C

mV/V

MOTOROLA ANALOG IC DEVICE DATA

MC1494

Figure 3. Linearity Figure 4. Input Resistance

E = 20 V

f = 20 Hz

10 V

VX off

Adjust RL for a null in E

To A

–

RX = 30 k RY = 62 k

11 12 7 8 1 3

VX 10

– +

–

MC1494

–+

20 k

50 k

R1 = 16 k

Linearity, Error =

E E

0.1

10 k

o(peak) S(peak)

+15 V

–15 V

22 k

–

MC1456

10 k 10 k

–

MC1456

Figure 5. Offset V oltages, Gain

50 k

0.1

f = 20 Hz e

1.0 M

30 k 62 k

11 12 7 8 1 3

– +

–

MC1494

–+

8.2 k

Rin X =

Rin Y =

– 2

[]

[

– 2

16 k

47 k

Ω

]

14 15

+15 V

0.1

–15 V

0.1

Figure 6. Input Bias Current/Input Offset

Current, Output Resistance

–

MC1456

VO off

30 k 62 k

11 12

–

7813

MC1494

8.2 k

16 k

+15 V

0.1 µF

+–

0.1

–15 V

47 k

VY off

10 13

9 6

30 k 62 k

11 12

– +

–

7813

MC1494

–

20 k

50 k

16 k

+15 V

0.1

–15 V

0.1 µF

22 k 50 k

Figure 7. Frequency Response Figure 8. Common Mode

30 k 62 k

11 12

–

7813

MC1494

8.2 k

16 k

+–

MOTOROLA ANALOG IC DEVICE DATA

0.1 µF

0.1

CO = 3.0 pF

+15 V

–15 V

47 k R

30 k 62 k

11 12

CMV

(20 Hz)

–

7813

MC1494

8.2 k

16 k

0.1 µF

+–

0.1

+15 V

–15 V

47 k

MC1494

Figure 9. Power Supply Sensitivity Figure 10. Burn–In

30 k 62 k

10 13

9 6

11 12

+ –

7813

MC1494

8.2 k

VR–V

16 k

+–

24 +

Figure 11. Frequency Response of Y Input

versus Load Resistance

5.0 0

RL = 47 k

– 5.0

RELATIVE GAIN (dB)

–10

VY = 1.0 Vrms, VX = 10 Vdc RX = 30 kΩ, RY = 62 k

–15

CO = 6.0 pF

–20

Ω

f, FREQUENCY (Hz)

0.1 µF

–15 V

RL = 1.0 k

RL = 33 k

Ω

+15 V

100 Hz

Ω

RL = 10 k

Ω

47 k

16 k 1

8.2 k

–15 V

0.1 µF

62 k

3 4 5

MC1494

+15 V

0.1 µF

30 k

Vin – +10 V

47 k

Figure 12. Frequency Response of X Input

versus Load Resistance

15 10

Ω

5.0

– 5.0

RELATIVE GAIN (dB)

–10

VX = 1.0 Vrms, VY = 10 Vdc RX = 30 kΩ, RY = 62 K

–15

Ω

CO = 6.0 pF

–20

f, FREQUENCY (Hz)

RL = 1.0 k

RL = 47 k

Ω

RL = 33 k

RL =

10 k

Ω

Figure 13. Linearity versus RX or RY with K = 1

RX RY

E or E , LINEARITY ERROR (%)

0.4

0.3

0.2

0.1

2.0 4.0 6.0 8.0

4.0 8.0 12 16 20

RL Adjusted for K = 1 Vin = 2.0 Vpp

RX (k RY (k

Figure 14. Linearity versus RX or RY with K = 1/10

0.6

0.5

0.4

0.3

RX RY

E or E , LINEARITY ERROR (%)

0.2

Ω

)

Ω

)

20 30 40 50 40 60 80 100

RL Adjusted for K = 1/10 Vin = 20 Vpp

RX (kΩ) RY (k

Ω

)

MOTOROLA ANALOG IC DEVICE DATA

MC1494

Figure 15. Large Signal V oltage versus Frequency Figure 16. Scale Factor (K) versus T emperature

0.108

V , OUTPUT VOL TAGE (Vpp)

100 1.0 k 10 k 100 k

With MC1456 Buffer Op Amp

No Op Amp, RL = 47 k

f, FREQUENCY (Hz)

Ω

CIRCUIT DESCRIPTION

0.106

0.104

0.102

0.1

0.098

K, SCALE FACTOR

0.096

0.094

– 55 – 35 –15 5.0 25 45 65 85 105 125

TA, AMBIENT TEMPERATURE (

K Factor Adjusted for 1/10 at 25°C)

145

Introduction

The MC1494 is a monolithic, four–quadrant multiplier that operates on the principle of variable transconductance. It features a single–ended current output referenced to ground and provides two complementary regulated voltages for use with the offset adjust circuits to virtually eliminate sensitivity of the offset voltage nulls to changes in supply voltages.

As shown in Figure 17, the MC1494 consists of a multiplier proper and associated peripheral circuitry to provide these features.

Regulator

The regulator biases the entire MC1494 circuit making it essentially independent of supply variation. It also provides two convenient regulated supply voltages which can be used in the offset adjust circuitry. The regulated output voltage at Pin 2 is approximately + 4.3 V, while the regulated voltage at Pin 4 is approximately – 4.3 V. For optimum temperature stability of these regulated voltages, it is recommended that |I2| = |I4| = 1.0 mA (equivalent load of 8.6 kΩ). As will be shown later, there will normally be two 20 kΩ potentiometers and one 50 kΩ potentiometer connected between Pins 2 and 4.

The regulator also establishes a constant current reference that controls all of the constant current sources in the MC1494. Note that all current sources are related to current I1 which is determined by R1. For best temperatures performance, R1 should be 16 kΩ so that I1 ≈ 0.5 mA for all applications.

Multiplier

The multiplier section of the MC1494 (center section of Figure 17) is nearly identical to the MC1495 and is discussed in detail in Application Note AN489,

Operation of the MC1495

. The result of this analysis is that

Analysis and Basic

the differential output current of the multiplier is given by:

2VX V

IA – IB = ∆I

[

RXRYI

Differential Current Converter

This portion of the circuitry converts the differential output current (IA –IB) of the multiplier to a single–ended output current (IO); IO = IA – I

IO =

2VX V

RXRYI

The output current can be easily converted to an output voltage by placing a load resistor RL from the output (Pin 14) to ground (Figure 19) or by using an op amp as a current–to–voltage converter (Figure 18). The result in both circuits is that the output voltage is given by:

2RL VX V

VO =

where, K (scale factor) =

RXRYI

= KVXV

DC OPERA TION

Selection of External Components

For low frequency operation the circuit of Figure 18 is recommended. For this circuit, RX = 30 kΩ, RY = 62 kΩ, R1 = 16 kΩ and, hence, I1 ≈ 0.5 mA. Therefore, to set the scale factor (K) equal to 1/10, the value of RL can be calculated to be:

RXRYI (2) (10)

RXRYI

(30 k) (62 k) (0.5 mA)

K =

RL =

RL = 46.5 k

Thus, a reasonable accuracy in scale factor can be achieved by making RL a fixed 47 kΩ resistor. However , if it is desired that the scale factor be exact, RL can be comprised of a fixed resistor and a potentiometer as shown in Figure 18.

Therefore, the output is proportional to the product of the two input voltages.

MOTOROLA ANALOG IC DEVICE DATA

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