Synthesized Function Generators
DS360 — Ultra-low distortion function generator

DS360 Function Generator· 10 mHz to 200 kHz frequency range· <−100 dBc distortion (to 20 kHz)· Sine, square, white and pink noise

The performance of a low-distortion analog source and theprecision 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 offeatures including sweeps and bursts, the DS360 is the ideal
source for audio frequency applications.

· 20 µVpp to 40 Vpp output range

Ultra-Low Distortion and Noise· Linear and log frequency sweeps

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. Careful shielding and board layout keep
the output noise to a minimum, making the DS360 theinstrument of choice for audio research and development,
manufacturing, and automated testing.

· 25 ppm frequency accuracy· 10 MHz reference input (opt.)· Balanced and unbalanced outputs· RS-232 and GPIB interfaces· DS360 ... $3095 (U.S. list)

Stanford Research Systems

Frequency Stability
Low-distortion analog sources have impressive THD
specifications, but suffer with poor frequency accuracy andresolution. 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 fromthe front panel and have it mean something!

phone: (408)744-9040
www.thinkSRS.com

DS360 Low Distortion Function Generator

Waveforms
The DS360 generates clean sine waves 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 wave andsquare 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 tostandard waveforms, the DS360 outputs white noise, pinknoise and band-limited white noise.
Audio Outputs
All functions and parameters are easily set using the frontpanel keypad and spin knob. A wide 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 canbe configured as balanced or unbalanced, with amplitudes
from 20.0 µVpp to 80.0 Vpp (balanced) and 10.0 µVpp to40.0 Vpp (unbalanced). Chassis ground and output commonbanana jacks are also provided.

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.

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 10 mHz and
200 kHz with sweep times between 0.3 ms and 100 s. Sweeps
can be single-shot or repetitive, and the instrument cansweep both up and down in frequency. The DS360 providesoutstanding 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 waves and squarewaves. 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 automatedtesting. With standard IEEE-488.2 (GPIB) and RS-232
interfaces, the DS360 is fully programmable — a feature seldomfound in low-distortion sources. All instrument functions can becontrolled or queried through the computer interfaces.

THD + N vs. Frequency (Hz)DS360 rear panel

Stanford Research Systems

phone: (408)744-9040
www.thinkSRS.com

DS360 Specifications

Waveforms

Sine or Square Burst

Sine

On cycles
Repetition rate
Triggering

Frequency range
0.01 Hz to 200.000 kHz
THD (1 Vrms unbalanced, 2 Vrms balanced)(<5 kHz)–110 dB (typ.), –106 dB (max.)(5 to 20 kHz)–104 dB (typ.), –100 dB (max.)(20 to 40 kHz)–100 dB (typ.), –96 dB (max.)(40 to 100 kHz)–90 dB (typ.), –85 dB (max.)(100 to 200 kHz) –76 dB (typ.), –68 dB (max.)
THD (10 Vrms unbalanced, 20 Vrms balanced)(<5.0 kHz)–109 dB (typ.), –105 dB (max.)(5 to 20 kHz)–103 dB (typ.), –99 dB (max.)(20 to 40 kHz)–98 B (typ.), –93 dB (max.)(40 to 100 kHz)–88 dB (typ.), –83 dB (max.)(100 to 200 kHz) –76 dB (typ.), –68 dB (max.)

Off level
Off resolution
Max. off attenuation

White or Pink Noise Burst
On time
Repetition time
Triggering
Off level
Resolution

SquareFrequency range
Rise time
Even harmonics

0.01 Hz to 200 kHz
1.3 µs<–60 dBc (to 20 kHz)White NoiseBandwidthFlatness
Crest factor

DC to 200 kHz<1.0 dB, 1 Hz to 100 kHz
11 dB

0.5, 1 to 65534 cycles
1 to 65535 cycles
Internal, external, single-shot,externally gated
0.0 % to 100.0 % (of on level)
0.1 %–90 dBc (1 kHz)–70 dBc (10 kHz)–50 dBc (100 kHz)10 µs to 599.9 s
20 µs to 600 s
Internal, external, single-shot,
externally gated
0.0 % to 100.0 % (of on level)
0.1 %Sine or Square Sweep
Type
Range
Rate
Resolution
Flatness

Linear or logarithmic
0.01 Hz to 200.000 kHz
0.1 Hz to 3.1 kHz
2 digits±0.1 dB (1 %)Frequency
Pink Noise
Resolution
BandwidthFlatness

10 Hz to 200 kHz<3.0 dB (20 Hz to 20 kHz)(measured using 1/3 oct. analysis)
12 dB

Crest factor

Accuracy

6 digits or 10 mHz(whichever is greater)
25 ppm (0.0025 %) + 4 mHz(20 °C to 40 °C)

Amplitude
Bandwidth Limited Noise
Unbalanced outputsBandwidthCenter frequency
Flatness (in band)
Crest factor
BasebandNon-baseband

100 Hz, 200 Hz, 400 Hz, 800 Hz,
1.6 kHz, 3.2 kHz, 6.4 kHz, 12.8 kHz,
25.6 kHz, 51.2 kHz, 102.4 kHz
0 Hz to 200.0 kHz(200 Hz increments)<1.0 dB

Resolution
12 dB (0 Hz center frequency)
15 dB

Two-ToneType
Sine frequency
Square frequency
Square resolution
SFDR

Balanced outputs

Sine-sine, sine-square0.01 Hz to 200 kHz
0.1 Hz to 5 kHz
2 digits>90 dB

Stanford Research Systems

Accuracy
Sine and Square
Two-toneWhite noise
Pink noise

5.0 µVpp to 14.4 Vpp (50 Ω load )5.0 µVpp to 20.0 Vpp (600 Ω load )10.0 µVpp to 40.0 Vpp (Hi-Z load )10 µVpp to 28.8 Vpp (50 Ω load )10 µVpp to 28.8 Vpp (150 Ω load )10 µVpp to 40.0 Vpp (600 Ω load )20 µVpp to 80.0 Vpp (Hi-Z load )4 digits or 1 µV, whichever isgreater (Vpp or Vrms),
0.1 dB (dBm or dBV)
±0.1 dB (1 %)±0.1 dB (1 %)±0.175 dB (2 %)±0.35 dB (4 %)phone: (408)744-9040
www.thinkSRS.com

DS360 Specifications

Broadband Noise

Unbalanced(1 kHz sine wave into Hi-Z load
at freq. > 1 kHz)<12.6 mVpp
<4 nV/√Hz
12.6 mVpp to 126 mVpp <7.5 nV/√Hz126 mVpp to 1.26 Vpp <15 nV/√Hz
1.26 Vpp to 10 Vpp<100 nV/√Hz
10 Vpp to 40 Vpp<500 nV/√Hz

Floating voltage

OffsetStability
Internal
External
Indicators

Unbalanced output

10 MHz Reference Input (Opt. 03)
Requirements

0 to ±7.4 VDC (50 Ω load )0 to ±10.0 VDC (600 Ω load )0 to ±20.0 VDC (Hi-Z load )Not active
3 digits

Balanced outputResolutionAccuracy(all except pink noise)
1 % ± 25 mV (Vp + offset > 0.63 V)
1 % ± 2.5 mV (0.63 V > Vp + offset > 0.063 V)
1 % ± 250 µV (63 mV > Vp + offset > 6.3 mV)
1 % ± 50 µV (Vp + offset < 6.3 mV)

Sine or TTL, 0.4 to 7 Vpp,
10 MHz ± 50 ppm±25 ppm
Same as stability of ext. reference
External reference detected, Locked

Other Outputs
Sync

TTL level (same frequencyand phase as output)
TTL pulse marks burst (TTL highfor ON time)
TTL pulse starts sweep or burst
TTL high activates gated burst
TTL pulse marks beginning of sweep

Burst out
Trigger/gate inSweep(pink noise)
1 % ± 200 mV (Vp + offset > 0.63 V)
1 % ± 20 mV (0.63 V > Vp + offse > 0.063 V)
1 % ± 2 mV (63 mV > Vp + offset > 6.3 mV)
1 % ± 200 µV (Vp + offset < 6.3 mV)

GeneralComputer interfaces
SizeWeightPowerOutputs
Configuration
Connectors
Source impedance
Balanced50 Ω ± 3 %600 Ω ± 1 %Hi-Z (25 Ω ± 1 Ω)
±40 VDC (max.)

GPIB and RS-232. All instrument
functions can be controlled.
17" × 3.5" × 16.25" (WHD)
17 lbs.
50 W, 100/120/220/240 VAC,
50/60 HzOne year parts and labor on defects
in materials and workmanship

Balanced and unbalanced
Floating BNCs, banana plugs andXLR jackWarranty

50 Ω ± 3 %150 Ω ± 2 %600 Ω ± 1 %Hi-Z (50 Ω ± 3 %)Ordering Information
DS360
Option 03
O360RM

Low-distortion function generator
10 MHz reference input
Rack mount kit

DS360 block diagram

Stanford Research Systems

phone: (408)744-9040
www.thinkSRS.com