REV. 0

AD5302/AD5312/AD5322

–6–

DAC-TO-DAC CROSSTALK

This is the glitch impulse transferred to the output of one DAC

due to a digital code change and subsequent output change of

the other DAC. This includes both digital and analog crosstalk.

It is measured by loading one of the DACs with a full-scale code

change (all 0s to all 1s and vice versa) while keeping

LDAC low

and monitoring the output of the other DAC. The area of the

glitch is expressed in nV-secs.

DC CROSSTALK

This is the dc change in the output level of one DAC in re-

sponse to a change in the output of the other DAC. It is mea-

sured with a full-scale output change on one DAC while

monitoring the other DAC. It is expressed in

µV.

POWER-SUPPLY REJECTION RATIO (PSRR)

This indicates how the output of the DAC is affected by

changes in the supply voltage. PSRR is the ratio of the change in

±10%.

REFERENCE FEEDTHROUGH

This is the ratio of the amplitude of the signal at the DAC out-

put to the reference input when the DAC output is not being

updated (i.e.,

LDAC is high). It is expressed in dBs.

TOTAL HARMONIC DISTORTION

This is the difference between an ideal sine wave and its attenu-

ated version using the DAC. The sine wave is used as the refer-

ence for the DAC and the THD is a measure of the harmonics

present on the DAC output. It is measured in dBs.

MULTIPLYING BANDWIDTH

The amplifiers within the DAC have a finite bandwidth. The

multiplying bandwidth is a measure of this. A sine wave on the

reference (with full-scale code loaded to the DAC) appears on

the output. The multiplying bandwidth is the frequency at

which the output amplitude falls to 3 dB below the input.

CHANNEL-TO-CHANNEL ISOLATION

This is a ratio of the amplitude of the signal at the output of one

DAC to a sine wave on the reference input of the other DAC. It

is measured in dBs.

ACTUAL

IDEAL

GAIN ERROR

PLUS

OFFSET ERROR

OUTPUT

VOLTAGE

POSITIVE

OFFSET

ERROR

DAC CODE

NEGATIVE

OFFSET

ERROR

AMPLIFIER

FOOTROOM

(1mV)

DEADBAND

Figure 2. Transfer Function with Negative Offset

OUTPUT

VOLTAGE

POSITIVE

OFFSET

ERROR

DAC CODE

GAIN ERROR

PLUS

OFFSET ERROR

ACTUAL

IDEAL

Figure 3. Transfer Function with Positive Offset