AD9835

–4–

REV. 0

ABSOLUTE MAXIMUM RATINGS*

°C unless otherwise noted)

AVDD to AGND . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V

DVDD to DGND . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V

AVDD to DVDD . . . . . . . . . . . . . . . . . . . . . –0.3 V to +0.3 V

AGND to DGND. . . . . . . . . . . . . . . . . . . . . . –0.3 V to +0.3 V

Digital I/O Voltage to DGND . . . . . –0.3 V to DVDD + 0.3 V

Analog I/O Voltage to AGND . . . . . –0.3 V to AVDD + 0.3 V

Operating Temperature Range

Industrial (B Version) . . . . . . . . . . . . . . . . –40

°C to +85°C

Storage Temperature Range . . . . . . . . . . . . –65

°C to +150°C

Maximum Junction Temperature . . . . . . . . . . . . . . . .+150

°C

TSSOP

θ

. . . . . . . . . . . . . . . 158

°C/W

Lead Temperature, Soldering

Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . +215

°C

Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . .+220

°C

ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . > 4500 V

*Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the

device at these or any other conditions above those listed in the operational sections

of this specification is not implied. Exposure to absolute maximum rating condi-

tions for extended periods may affect device reliability.

ORDERING GUIDE

Temperature

Package

Package

Model

Range

Description

Option*

AD9835BRU

–40

°C to +85°C

16-Lead TSSOP RU-16

*RU = Thin Shrink Small Outline Package (TSSOP).

PIN CONFIGURATION

14

13

12

11

16

15

10

9

8

1

2

3

4

7

6

5

TOP VIEW

(Not to Scale)

AD9835

FS ADJUST

AGND

IOUT

AVDD

COMP

REFIN

REFOUT

DVDD

FSELECT

PSEL1

PSEL0

DGND

MCLK

SCLK

SDATA

FSYNC

TERMINOLOGY

Integral Nonlinearity

This is the maximum deviation of any code from a straight line

passing through the endpoints of the transfer function. The end-

points of the transfer function are zero scale, a point 0.5 LSB

below the first code transition (000 . . . 00 to 000 . . . 01)

and full scale, a point 0.5 LSB above the last code transition

(111 . . . 10 to 111 . . . 11). The error is expressed in LSBs.

Differential Nonlinearity

This is the difference between the measured and ideal 1 LSB

change between two adjacent codes in the DAC.

Signal to (Noise + Distortion)

Signal to (Noise + Distortion) is measured signal to noise at the

output of the DAC. The signal is the rms magnitude of the

fundamental. Noise is the rms sum of all the nonfundamental

ing the dc component. Signal to (Noise + Distortion) is depen-

dent on the number of quantization levels used in the digitization

process; the more levels, the smaller the quantization noise.

The theoretical Signal to (Noise + Distortion) ratio for a sine

wave input is given by

Signal to (Noise + Distortion) = (6.02N + 1.76) dB

where N is the number of bits. Thus, for an ideal 10-bit con-

verter, Signal to (Noise + Distortion) = 61.96 dB.

Total Harmonic Distortion

Total Harmonic Distortion (THD) is the ratio of the rms sum

of harmonics to the rms value of the fundamental. For the

AD9835, THD is defined as

THD

= 20 log

3

4

5

6

2

)

sixth harmonic.

Output Compliance

The output compliance refers to the maximum voltage that can

be generated at the output of the DAC to meet the specifica-

tions. When voltages greater than that specified for the output

compliance are generated, the AD9835 may not meet the speci-

fications listed in the data sheet.

Spurious Free Dynamic Range

Along with the frequency of interest, harmonics of the funda-

mental frequency and images of the MCLK frequency are

present at the output of a DDS device. The spurious free dy-

namic range (SFDR) refers to the largest spur or harmonic

present in the band of interest. The wideband SFDR gives the

magnitude of the largest harmonic or spur relative to the magni-

tude of the fundamental frequency in the bandwidth

±2 MHz

about the fundamental frequency. The narrow band SFDR gives

the attenuation of the largest spur or harmonic in a bandwidth of

±50 kHz about the fundamental frequency.

Clock Feedthrough

There will be feedthrough from the MCLK input to the analog

output. Clock feedthrough refers to the magnitude of the

MCLK signal relative to the fundamental frequency in the

AD9835’s output spectrum.