Figure 12. Y-Input Nonlinearity @ X = –2.5 V

Feedthrough

In the ideal case, the output of the multiplier should be zero if

either input is zero. In reality, some portion of the nonzero input

will “feedthrough” the multiplier and appear at the output. This is

caused by the product of the nonzero input and the offset voltage of

the “zero” input. Introducing an offset equal to and opposite of the

“zero” input offset voltage will null the linear component of the

feedthrough. Residual feedthrough at the output of the multiplier

is then irreducible core nonlinearity.

Typical X- and Y-input feedthrough curves for the MLT04 are

shown in Figures 7 and 8, respectively. These curves illustrate

MLT04 feedthrough after “zero” input offset voltage trim.

Residual X-input feedthrough measures 0.08% of full scale,

whereas residual Y-input feedthrough is almost immeasurable.

Figure 7. X-Input Feedthrough with Y

Figure 8. Y-Input Feedthrough with X

Nonlinearity

Multiplier core nonlinearity is the irreducible component of error.

It is the difference between actual performance and “best-straight-

line” theoretical output, for all pairs of input values. It is expressed

as a percentage of full scale with all other dc errors nulled. Typical

X- and Y-input nonlinearities for the MLT04 are shown in Figures

9 through 12. Worst-case X-input nonlinearity measured less than

0.2%, and Y-input nonlinearity measured better than 0.06%. For

modulator/demodulator or mixer applications it is, therefore,

recommended that the carrier be connected to the X-input while

the signal is applied to the Y-input.

REV. B

Figure 10. X-Input Nonlinearity @ Y = –2.5 V

Figure 11. Y-Input Nonlinearity @ X = +2.5 V

MLT04

Figure 9. X-Input Nonlinearity @ Y = +2.5 V

100

90

10

0%

HORIZONTAL – 0.5V/DIV

Y-INPUT: ±2.5V @ 10Hz

X

OS

NULLED

T

A

= +25°C

100

90

10

0%

HORIZONTAL – 0.5V/DIV

X-INPUT: ±2.5V @ 10Hz

Y-INPUT: +2.5V

Y

OS

NULLED

T

A

= +25°C

100

90

10

0%

HORIZONTAL – 0.5V/DIV

X-INPUT: ±2.5V @ 10Hz

Y

OS

NULLED

T

A

= +25°C

100

90

10

0%

HORIZONTAL – 0.5V/DIV

X-INPUT: ±2.5V @ 10Hz

Y-INPUT: –2.5V

Y

OS

NULLED

T

A

= +25°C

100

90

10

0%

HORIZONTAL – 0.5V/DIV

Y-INPUT: ±2.5V @ 10Hz

X-INPUT: +2.5V

X

OS

NULLED

T

A

= +25°C

100

90

10

0%

HORIZONTAL – 0.5V/DIV

Y-INPUT: ±2.5V @ 10Hz

X-INPUT: –2.5V

X

OS

NULLED

T

A

= +25°C

–4–