AD9748 View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

AD9748

8-Bit, 165 MSPS TxDAC® D/A Converter

Analog Devices 

AD9748

DEFINITIONS OF SPECIFICATIONS

Linearity Error (Also Called Integral Nonlinearity or INL)

Linearity error is defined as the maximum deviation of the actual

analog output from the ideal output, determined by a straight

line drawn from zero to full scale.

Differential Nonlinearity (or DNL)

DNL is the measure of the variation in analog value, normalized

to full scale, associated with a 1 LSB change in digital input code.

Monotonicity

A D/A converter is monotonic if the output either increases or

remains constant as the digital input increases.

Offset Error

The deviation of the output current from the ideal of zero is called

the offset error. For IOUTA, 0 mA output is expected when the

inputs are all 0s. For IOUTB, 0 mA output is expected when all

inputs are set to 1s.

Gain Error

The difference between the actual and ideal output span. The

actual span is determined by the output when all inputs are set to

1s minus the output when all inputs are set to 0s.

Output Compliance Range

The range of allowable voltage at the output of a current output

DAC. Operation beyond the maximum compliance limits may

cause either output stage saturation or breakdown, resulting in

nonlinear performance.

Temperature Drift

Temperature drift is specified as the maximum change from the

ambient (25∞C) value to the value at either TMIN or TMAX. For

offset and gain drift, the drift is reported in ppm of full-scale range

(FSR) per ∞C. For reference drift, the drift is reported in ppm per ∞C.

Power Supply Rejection

The maximum change in the full-scale output as the supplies are

varied from nominal to minimum and maximum specified voltages.

Settling Time

The time required for the output to reach and remain within a

specified error band about its final value, measured from the start

of the output transition.

Glitch Impulse

Asymmetrical switching times in a DAC give rise to undesired

output transients that are quantified by a glitch impulse. It is

specified as the net area of the glitch in pV-s.

Spurious-Free Dynamic Range

The difference, in dB, between the rms amplitude of the output

signal and the peak spurious signal over the specified bandwidth.

Total Harmonic Distortion (THD)

THD is the ratio of the rms sum of the first six harmonic compo-

nents to the rms value of the measured input signal. It is expressed

as a percentage or in decibels (dB).

Multitone Power Ratio

The spurious free dynamic range containing multiple carrier tones

of equal amplitude. It is measured as the difference between the

rms amplitude of a carrier tone to the peak spurious signal in

the region of a removed tone.

3.3V

*AWG2021 CLOCK

RETIMED SO THAT

THE DIGITAL DATA

TRANSITIONS ON

FALLING EDGE OF

50% DUTY CYCLE

CLOCK.

DVDD

0.1␮F

RSET 3.3V

50⍀

CLK؉

CLK؊

3.3V

+1.20V REF

REFIO

FS ADJ

150pF

DVDD

DCOM

SEGMENTED

SWITCHES

AVDD ACOM

CURRENT AD9748

SOURCE

ARRAY

LSB

SWITCHES

IOUTA

IOUTB

CLKVDD

CLKCOM

LATCHES

DCOM

SLEEP DIGITAL DATA INPUTS (DB7–DB0)

RETIMED

CLOCK

OUTPUT*

LECROY 9210

PULSE GENERATOR

CLOCK

OUTPUT

DIGITAL

DATA

TEKTRONIX AWG-2021

WITH OPTION 4

MODE

CMODE

50⍀

50⍀

20pF

100⍀

MINI-CIRCUITS

T1–1T

ROHDE &

SCHWARZ

FSEA30

SPECTRUM

ANALYZER

20pF

Figure 2. Basic AC Characterization Test Setup

–6–

REV. 0

Share Link: