REV. F

AD5305/AD5315/AD5325

–7–

Major-Code Transition Glitch Energy

Major-code transition glitch energy is the energy of the impulse

injected into the analog output when the code in the DAC

register changes state. It is normally specified as the area of the

glitch in nV-s and is measured when the digital code is changed by

1 LSB at the major carry transition (011 . . . 11 to 100 . . . 00,

or 100 . . . 00 to 011 . . . 11).

Digital Feedthrough

Digital feedthrough is a measure of the impulse injected into the

analog output of the DAC from the digital input pins of the

device when the DAC output is not being updated. It is specified

in nV-s and is measured with a worst-case change on the

digital input pins, e.g., from all 0s to all 1s or vice versa.

Digital Crosstalk

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

at midscale in response to a full-scale code change (all 0s to all

1s and vice versa) in the input register of another DAC. It is

expressed in nV-s.

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

another 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) with the

LDAC bit set

low and monitoring the output of another DAC. The energy of

the glitch is expressed in nV-s.

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.

Total Harmonic Distortion

This is the difference between an ideal sine wave and its attenuated

version using the DAC. The sine wave is used as the reference for

the DAC and the THD is a measure of the harmonics present

on the DAC output. It is measured in dB.

ACTUAL

IDEAL

GAIN ERROR

PLUS

OFFSET ERROR

OUTPUT

VOLTAGE

NEGATIVE

OFFSET

ERROR

DAC CODE

AMPLIFIER

FOOTROOM

(1mV)

DEAD BAND CODES

NEGATIVE

OFFSET

ERROR

Figure 2. Transfer Function with Negative Offset

OUTPUT

VOLTAGE

POSITIVE

OFFSET

DAC CODE

GAIN ERROR

PLUS

OFFSET ERROR

ACTUAL

IDEAL

Figure 3. Transfer Function with Positive Offset