Atec DS360 User Manual

· 1 mHz to 200 kHz frequency range

· <−100 dBc distortion (to 20 kHz)

· Sine, square, white and pink noise

· 20

µµ

Vpp to 40 Vpp output range

· Linear and log frequency sweeps

· 25 ppm frequency accuracy

· SPDIF/EIAJ and AES-EBU outputs

· Balanced and unbalanced outputs

· RS-232 and GPIB interfaces

· DS360 ... $2595

(U.S. list)

Stanford Research Systems phone: [phone]

www.thinkSRS.com

The performance of a low-distortion analog source and the
precision of direct digital synthesis (DDS) is combined in the
DS360. With less than 0.001 % total harmonic distortion (THD),
25 ppm frequency accuracy and a broad range of features
including standard waveforms, sweeps and bursts, the DS360
is the ideal source for audio frequency applications.

Ultra-Low Distortion and Noise

Unlike conventional RC oscillators, the DS360 uses digital
signal processing and a precision 20-bit D/A converter to
provide better than −100 dB distortion over the audio
frequency range. With its DDS architecture, the DS360 has
the features and flexibility of a contemporary synthesized
function generator. Every effort has been made to keep the
DS360 as quiet as possible. Careful shielding and board layout
keep the output noise to a minimum, making the DS360 the
instrument of choice for audio research and development,
manufacturing and automated testing.

Frequency Stability

Low-distortion analog sources have impressive THD
specifications, but poor frequency accuracy and resolution.
The DS360 delivers 0.0025 % frequency accuracy over its
entire frequency range. It has 6-digit frequency resolution
from 1 mHz to 200 kHz and a steady 25 ppm frequency
stability. You can actually dial in 123,456 Hz from the front
panel and have it mean something!

DS360 Function Generator

Synthesized Function Generators

DS360  Ultra-low distortion function generator

Waveforms

The DS360 generates clean sine and square waves as well as
a two-tone signal for IMD testing. The two-tone signal is
defined as either two sine waves or a sine and square wave.
Both frequency and amplitude are independently set for the
two waves allowing standard two-tone formats like SMPTE,
DIM and CCIF to be generated. In addition to standard
waveforms, the DS360 outputs white noise, pink noise and
band-limited white noise.

Audio Outputs

All functions and parameters are easily set using the front­panel keypad and spin knob. Awide variety of amplitude units
including Vrms, Vpp, dBV, dBm and dBrel can be selected.
Front-panel outputs including XLR, BNC and dual banana
jacks assure compatibility with any system. The outputs can
be configured as balanced or unbalanced, with amplitudes
from 20.0 µVpp to 80.0 Vpp (balanced), and 10.0 µVpp to

40.0 Vpp (unbalanced). Chassis ground and output common
banana jacks are also provided. Rear-panel digital outputs
conform to AES-EBU and SPDIF/EIAJ formats. An XLR jack
is provided for the AES-EBU output, and both fiber optic and
coaxial connectors are provided for the SPDIF/EIAJ output.

Sweeps and Bursts

Unlike single frequency analog sources, the DS360 generates
low-distortion frequency sweeps over its entire frequency
range. Linear and log sweeps are set between 1 mHz and
200 kHz with sweep times between 0.3 ms and 100 s. Sweeps
can be single-shot or repetitive and the instrument can sweep
both up and down in frequency. The DS360 provides
outstanding amplitude flatness (0.5 % up to 20 kHz) during
frequency sweeps and has a TTL level sweep marker output
for synchronizing external equipment.

The DS360 also creates tone bursts of sine and square waves.
The number of ON cycles, repetition rate, and the OFF
amplitude level can all be adjusted. Sweeps and bursts may be
triggered from the internal rate generator or an external
trigger, or they can be externally gated.

Computer Control

The DS360 is designed for benchtop use as well as automated
testing. With standard IEEE-488.2 (GPIB) and RS-232

interfaces, the DS360 is fully programmablea feature seldom
found in low-distortion sources. All instrument functions can
be controlled or queried through the computer interfaces.

DS360 Low Distortion Function Generator

Stanford Research Systems phone: [phone]

www.thinkSRS.com

DS360 rear panel

THD vs. Frequency (Hz)

Residual distortion for a 1 kHz, 28 Vrms (balanced) sine
wave after passing through a non-distorting notch filter
to attenuate the fundamental.

THD+N vs. Frequency (Hz)

-100.0

-105.0

-110.0

-115.0

-120.0

-125.0

-130.0

-135.0

-140.0

-145.0

-150.0

0.0 2.00k 4.00k 6.00k 8.00k 10.0k 12.0k 14.0k 16.0k 18.0k 20.0k

-60.00

-70.00

-80.00

-90.00

-100.00

-110.00

-120.00

20 100 1k 10k 20k