Synthesized Function Generators
DS345 — 30 MHz function and arbitrary waveform generator

DS345 Function/Arb Generator· 1 µHz to 30.2 MHz frequency range· 1 µHz frequency resolution· Sine, square, ramp, triangle & noise· Phase-continuous frequency sweeps· AM, FM, burst and phase modulation· 16,300 point arbitrary waveforms· 10 MHz reference input· RS-232 and GPIB interfaces (opt.)

The DS345 is a full-featured 30 MHz synthesized function
generator that uses an innovative Direct Digital Synthesis(DDS) architecture. It generates many standard waveforms
with excellent frequency resolution (1 µHz), and has versatile
modulation capabilities including AM, FM, Burst, PM andfrequency sweeps. It also generates arbitrary waveforms witha fast 40 Msamples/s update rate.
Functions and Outputs
The DS345 generates sine waves and square waves atfrequencies up to 30.2 MHz, and triangle and ramp waveforms
up to 100 kHz. The frequency resolution for all functions is
1 µHz. In addition to the standard waveforms, the unit also
provides a wideband (10 MHz) white noise source.
Both the function output and a TTL SYNC output areavailable through floating, front-panel BNC connectors. Bothoutputs have 50 Ω output impedances and may be floatedup to ±40 V relative to earth ground. The amplitude of all
function outputs is adjustable from 10 mVpp to 10 Vpp with
3-digit resolution, and can be displayed in Vp, Vpp, Vrms ordBm. In addition, standard TTL and ECL output levels canbe selected.
Additional useful connectors are provided on the rear panel.
A trigger input is used to trigger arbitrary waveforms,
modulation patterns, sweeps and bursts, while a TTL trigger
output is provided to allow synchronization of external

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DS345 Function/Arbitrary Waveform Generator

devices to sweeps and bursts. A sweep output generates
a 0 to 10 V ramp synchronous with frequency sweeps. The
sweep marker outputs allow specified portions of a frequency
sweep to be highlighted on an oscilloscope.
A 10 MHz rear-panel input allows the DS345 to besynchronized to an external timebase. A 10 MHz rear-panel
output allows multiple DS345s to be phase locked together.

Phase modulation
selected with 1 % resolution. Negative values of modulation
correspond to Double Sideband Suppressed Carrier (DSBSC)
modulation. FM spans can be selected with 1 µHz resolution,and phase modulation can be set between 0° and 7200° with
0.001° resolution.
External Amplitude Modulation
Square, triangle and ramp waveforms
Modulation
The DS345 offers a wide variety of modulation options.
It contains an internal modulation generator which canmodulate any of its standard waveforms except noise. The
modulation waveform can be a sine, square, triangle, ramp
or an arbitrary waveform. Modulation rates from 1 mHz to10 kHz can be selected.

In addition to the internal modulation generator, the output
waveform can be amplitude modulated by an external signal
applied to the rear-panel AM input. This input is always active— even when other modulation types are turned on.

The modulation generator can provide amplitude modulation(AM), frequency modulation (FM), and phase modulation(PM). When using AM, modulation depths of ±100 % can beAmplitude modulation

Burst Modulation

Frequency modulation

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You can generate tone bursts of any output function except
noise. In burst mode, the DS345 will output an exact numberof complete waveform cycles after receiving a trigger. Byadjusting the phase, you can control where in the waveformthe burst begins. While using burst mode, the maximum

phone: (408)744-9040
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DS345 Function/Arbitrary Waveform Generator

Arbitrary Waveform Capability
The DS345 isn’t just a function generator. It’s also a fullfeatured arbitrary waveform generator. Output waveforms
have 12-bit vertical resolution, and can be played back at rates
up to 40 Msamples/s.
Since composing complex arbitrary waveforms at the keyboard
can be a tedious task, Arbitrary Waveform Composer (AWC)
software is provided at no charge. AWC is a menu-based
program which lets you create and edit arbitrary waveforms
on the screen, store them, and download them to the DS345.

Burst modulation
frequency for sine waves and square waves is 1 MHz, while
triangles and ramps are limited to 100 kHz. Burst mode may
be used with arbitrary waveforms at any frequency.
Frequency SweepsThe DS345 can frequency sweep any of its function outputs(except noise). You can sweep up or down in frequency using
linear or log sweeps. Unlike conventional function generators,
there are no annoying discontinuities or band-switchingartifacts when sweeping through certain frequencies.
The DS345’s DDS architecture inherently allows it toperform smooth, phase-continuous sweeps over it’s entire
frequency range.

Arbitrary waveform

Two sweep marker frequencies can be specified. Whenthe sweep crosses either of the marker frequencies, a TTLtransition is generated at the rear-panel MARKER output toallow synchronization of external devices.

AWC software
Frequency sweep

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DS345 Specifications

Harmonic distortion

Frequency Range
Max. Freq.
30.2 MHz30.2 MHz
100 kHz100 kHz
10 MHz10 MHzSine
SquareRamp
Triangle
Noise
Arbitrary

Resolution
1 µHz
1 µHz
1 µHz
1 µHz
(Gaussian weighting)
40 MHz/N(sample rate)

50 Ω
Output may float up to ±40 V(AC + DC) relative to earth ground.

AmplitudeRange
Resolution
Sine wave accuracy
5 to 10 Vpp0.01 to 5 Vpp

0.01 to 10 Vpp (50 Ω),
20 Vpp (Hi-Z)
3 digits (DC offset: 0 V)
(0 VDC offset)±0.2 dB (1 µHz to 20 MHz)
±0.5 dB (20 MHz to 30.2 MHz)
±0.4 dB (1 µHz to 20 MHz)
±0.5 dB (20 MHz to 30.2 MHz)Square wave accuracy
5 to 10 Vpp±3 % (1 µHz to 100 kHz)
±6 % (100 kHz to 20 MHz)
±15 % (20 MHz to 30.2 MHz)
0.01 to 5 Vpp±5 % (1 µHz to 100 kHz)
±8 % (100 kHz to 20 MHz)
±18 % (20 MHz to 30.2 MHz)
Triangle, ramp and±3 % (>5 Vpp)arbitrary accuracy ±5 % (<5 Vpp)

Rise/fall time
Asymmetry
OvershootRange±5 V (limited such that|VAC peak| + |VDC| < 5 V)
3 digits (VAC = 0)
1.5 % of setting + 0.2 mV(DC only)±0.8 mV to ±80 mV, depending on
AC and DC settings

Resolution
Accuracy

Rise/fall time
Linearity
Settling time

Spurious components
Phase noise

Sub-harmonic–45 dBc (non-harmonic, typ.)–55 dBc in a 30 kHz band (typ.)centered on the carrier, exclusive ofdiscrete spurious signals<–50 dBc

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45 ns (10 MHz Bessel filter)±0.5 % of full-scale output<1 µs to settle within 0.1 % of final
value at full output

Arbitrary Waveforms
Sample rate
Memory length
Resolution

40 MHz/N, N = 1 to 234 – 1
8 to 16,300 points
12 bits (0.025 % of full scale)

Phase
Range
Resolution±7199.999° with respect to arbitrary
starting phase
0.001°

Amplitude Modulation
SourceDistortion
DSB carrier
External inputInternal (sine, square, triangle orramp) or External
0 to 100 % AM or DSBSC
0.001 Hz to 10 kHz (internal),
15 kHz max. (external)<–35 dB at 1 kHz, 80 % depth<–35 dB (typ.) at 1 kHz modulation
rate (DSBSC)±5 V for 100 % modulation,
100 kΩ impedance, 15 kHz BW

Frequency Modulation
SourceSine Wave<15 ns (10 % to 90 %), at full output<1 % of period + 4 ns
<5 % of peak to peak amplitude atfull output

Ramps, Triangle and Arbitrary Waveforms

DepthRate

DC Offset

Frequency Range
DC to 100 kHz
0.1 MHz to 1 MHz
1 MHz to 10 MHz
10 MHz to 30 MHz

Square Wave

OutputSource impedance
GroundingLevel<–55 dBc<–45 dBc<–35 dBc<–25 dBc

Rate
Span

Internal (sine, square, triangle, ramp
or arbitrary)0.001 Hz to 10 kHz
1 µHz to 30.2 MHz (100 kHz fortriangle, ramp)

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DS345 Specifications

Phase Modulation
SourceRate
Span

GeneralInternal (sine, square, triangle, ramp)
0.001 Hz to 10 kHz±7199.999°

Interfaces

Linear or log, phase continuous
Up, down, up-down, single sweep
0.001 s to 1000 s
1 µHz to 30.2 MHz (to 100 kHz fortriangle, ramp)
Two markers may be set at anysweep point (TTL output)
0 to 10 V linear ramp signal,
synchronized to sweep

Non-volatile memory

Frequency Sweep
TypeWaveform
TimeSpanMarkers
Sweep output

Dimensions
WeightPowerWarranty

Opt. RS-232 (300 to 19.2 kbaud,DCE) and GPIB with DOS
based arbitrary waveform
software (AWC). All instrument
functions are controllable overthe interfaces.
Nine sets of instrument settings canbe saved and recalled.
8.5" × 3.5" × 13" (WHD)
10 lbs.
50 W, 100/120/220/240 VAC,
50/60 HzOne year parts and labor on defects
in materials and workmanship

Burst Modulation
Waveform

Any waveform except noise may beburst modulated.
Sine and square to 1 MHz,Triangle and ramp to 100 kHz,
Arbitrary to 40 MHz sample rate
1 to 30,000 cycles/burst (1 µs to500 s burst time limits)

Frequency

CountTrigger Generator
SourceRate (internal)
External trigger
OutputSingle, Internal, External, Line
0.001 Hz to 10 kHz(2-digit resolution)
Positive or negative edge, TTL
TTL level

DS345 rear panel (with Opt. 01)

Standard Timebase
Accuracy
Aging
Input

±5 ppm (20 °C to 30 °C)
5 ppm/year
10 MHz/N ± 2 ppm (N = 1 to 8),
1 Vpp minimum input level
10 MHz, >1 Vpp sine into 50 ΩOutput
Optional Timebase
TypeStabilityAging
Allan variance (1 s)Ovenized AT-cut oscillator<0.01 ppm, 20 °C to 60 °C<0.001 ppm/day<5 × 10–11

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Ordering Information
DS345
Option 01
Option 02
O345RMD
O345RMS

30 MHz function/arb. generator
GPIB, RS-232 and arb. software
10 ppb OCXO timebase
Double rack mount kit
Single rack mount kit

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