DS360

The Stanford Research Systems DS360 is an ultra-low distortion function generator that combines the low-distortion performance of an analog source with the high precision and flexibility of direct digital synthesis (DDS). Utilizing a 20-bit D/A converter and dedicated analog circuitry, the DS360 achieves exceptionally pure output waveforms with total harmonic distortion (THD) of better than -100 dB up to 20 kHz, making it an essential instrument for high-performance audio frequency testing, calibration, and research.

Audio Testing Calibration Signal Generation

Specifications

General

Parameter	Value
Interfaces	GPIB (IEEE-488.2), RS-232
Display	Custom backlit LCD

Physical

Parameter	Value
Power Supply	100/120/220/240 VAC, 50/60 Hz, 40 W
Operating Temperature	0 °C to 50 °C
Dimensions (W×H×D)	432 × 89 × 413 mm (17" × 3.5" × 16.25")
Weight	7.7 kg

Frequency Characteristics

Parameter	Value
Frequency Range (Sine)	10 mHz to 200 kHz
Frequency Range (Square)	10 mHz to 200 kHz
Frequency Resolution	6 digits or 10 mHz (whichever is greater)
Frequency Accuracy	±25 ppm (0.0025%)

Amplitude Characteristics

Parameter	Value
Amplitude Range (Balanced)	20.0 µVpp to 80.0 Vpp
Amplitude Range (Unbalanced)	10.0 µVpp to 40.0 Vpp
Amplitude Resolution	3 digits
Amplitude Accuracy (1 kHz)	±0.1 dB (±1.2%)
Amplitude Flatness	±0.1 dB (10 mHz to 20 kHz, unbalanced)
Amplitude Units	Vrms, Vpp, dBV, dBm, dBrel

Distortion and Spectral Purity

Parameter	Value
THD (<5 kHz, 1 Vrms unbal / 2 Vrms bal)	-110 dB (typ.), -106 dB (max.)
THD (5 to 20 kHz, 1 Vrms unbal / 2 Vrms bal)	-104 dB (typ.), -98 dB (max.)
THD (20 to 40 kHz, 1 Vrms unbal / 2 Vrms bal)	-100 dB (typ.), -96 dB (max.)
THD (40 to 100 kHz, 1 Vrms unbal / 2 Vrms bal)	-90 dB (typ.), -85 dB (max.)
THD (100 to 200 kHz, 1 Vrms unbal / 2 Vrms bal)	-76 dB (typ.), -68 dB (max.)
THD (<5.0 kHz, 10 Vrms unbal / 20 Vrms bal)	-109 dB (typ.), -105 dB (max.)
THD (5 to 20 kHz, 10 Vrms unbal / 20 Vrms bal)	-103 dB (typ.), -98 dB (max.)
THD (20 to 40 kHz, 10 Vrms unbal / 20 Vrms bal)	-98 dB (typ.), -93 dB (max.)
THD (40 to 100 kHz, 10 Vrms unbal / 20 Vrms bal)	-88 dB (typ.), -83 dB (max.)
THD (100 to 200 kHz, 10 Vrms unbal / 20 Vrms bal)	-76 dB (typ.), -68 dB (max.)

Waveform Types and Attributes

Parameter	Value
Waveforms	Sine, Square, Two-Tone, White Noise, Pink Noise, Bandlimited Noise
Two-Tone Signals	Two sines, or sine and square (SMPTE, DIM, CCIF formats)
Square Wave Rise/Fall Time	1.3 µs (10% to 90%)

Output Configuration

Parameter	Value
Output Configuration	Balanced and unbalanced
Output Connectors	XLR, BNC, dual banana jacks
Output Source Impedance	50 Ω, 150 Ω, 600 Ω
Output Isolation (Float Voltage)	Up to ±40 V relative to chassis ground

Modulation and Sweep

Parameter	Value
Sweep Type	Linear and Logarithmic
Sweep Frequency Range	10 mHz to 200 kHz
Sweep Direction	Up and Down
Sweep Time Range	1 ms to 2600 s
Sweep Marker Output	TTL level
Burst Mode	Tone bursts of sine and square waves
Burst Count Range	1 to 65534 cycles
Trigger Sources	Internal rate generator, external trigger, external gate

Timing and Synchronization

Parameter	Value
External Reference Input	10 MHz
Sync Output	Front-panel TTL level

Physical and Environmental

Parameter	Value
AC Line Input	100 V, 120 V, 220 V, 240 V AC (selectable)
AC Line Frequency	50 Hz or 60 Hz
Power Consumption	40 W

Noise & Distortion

Parameter	Value
SMPTE IMD	< -100 dB (0.001%)
CCIF IMD	< -110 dB (0.0003%)
Broadband Noise	< 15 nV/√Hz (f > 1 kHz)
Spurious Components	< -100 dBc (DC to 20 kHz), < -90 dBc (20 kHz to 200 kHz)
Phase Noise	< -110 dBc/Hz (at 1 kHz offset)

DC Offset

Parameter	Value
DC Offset Range (Balanced)	0 to ±20.0 V (offset + peak AC < 20 V)
DC Offset Range (Unbalanced)	0 to ±10.0 V (offset + peak AC < 10 V)
DC Offset Resolution	3 digits
DC Offset Accuracy (Unbalanced)	1.5% of setting + 0.1 mV (Vp <= 0.2 V); 1.5% of setting + 1.0 mV (Vp <= 2.0 V); 1.5% of setting + 10 mV (Vp <= 14.14 V)
DC Offset Accuracy (Balanced)	1.5% of setting + 0.2 mV (Vp <= 0.4 V); 1.5% of setting + 2.0 mV (Vp <= 4.0 V); 1.5% of setting + 20 mV (Vp <= 28.28 V)

Noise Waveform Specifications

Parameter	Value
White Noise Bandwidth	DC to 200 kHz
Pink Noise Bandwidth	DC to 200 kHz
Bandlimited Noise Center Frequency Range	10 Hz to 200 kHz
Bandlimited Noise Bandwidth Range	100 Hz to 199.9 kHz

Phase Control

Parameter	Value
Phase Range (Relative to Sync)	-180° to +180°
Phase Resolution	0.001°

General & Environmental

Parameter	Value
Temperature Coefficient	< (0.01% + 0.005 dB) per °C

Inputs & Outputs

Parameter	Value
Trigger Input Level	TTL
External Reference Input Level	TTL
External Reference Lock Range	±10 ppm

System & Interface

Parameter	Value
Setup Storage	9 setups (non-volatile)
RS-232 Baud Rates	300, 600, 1200, 2400, 4800, 9600 baud

Performance

Parameter	Value
Pink Noise Spectral Roll-off	3 dB/octave

Technology

Direct Digital Synthesis (DDS) with 20-bit D/A Conversion

Applications

Audio frequency research and development, high-fidelity equipment manufacturing, and automated audio testing