TTi Signal and Waveform Generator Products

TG2000 - Description and Specifications

TG2000 - 20MHz DDS Function Generator

0.001Hz to 20MHz frequency range
6 digits or 1mHz resolution
1ppm stability and 10ppm one year accuracy
Low distortion, high spectral purity sine waves
Internal phase continuous sweep, lin or log
AM, FSK, gated and tone switching modes
5mV to 20V pk-pk from 50 or 600 Ohms
Storage for multiple instrument set-ups
USB and RS232 Interfaces
Low cost

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A new price point for a DDS generator

The TG2000 breaks new ground by offering a 20MHz direct digital synthesis function generator at a significantly lower price point. Direct digital synthesis (DDS) is a technique for generating waveforms digitally using a phase accumulator, a look-up table and a DAC. The accuracy and stability of the resulting waveforms is related to that of the crystal master clock. The DDS generator offers not only exceptional accuracy and stability but also high spectral purity, low phase noise and excellent frequency agility.

Total digital control

Unlike some other generators which only provide digital control of frequency, every function of the TG2000 is digitally controlled via the front panel or the digital interfaces.

Wide frequency & amplitude range

The TG2000 can generate waveforms between 0.001Hz and 20MHz with a resolution of six digits and a one year accuracy better than 10ppm.
Amplitude is variable between 5mV and 20V pk-pk from a source impedance of 50W or 600W. Waveform quality remains excellent over the full amplitude range.

RS-232 & USB interfaces

The TG2000 includes both an RS-232 interface and USB interface as standard. These interfaces can be used for remote control of all of the instrument functions and for storing instrument set-ups.

Easy and convenient to use

The TG2000 is particularly easy to use. All of the main information is clearly displayed on a backlit LCD with 4 rows of 20 characters. Sub menus are used for the modulation modes and other complex functions. All parameters can be entered directly from the numeric keypad. Alternatively most parameters can be incremented or decremented using the rotary encoder for quasi-analogue control.

Sweep

All waveforms can be swept over their full frequency range (0.1Hz minimum) at a rate variable between 20 milliseconds and 15 minutes. The sweep is fully phase continuous. Sweep can be linear or logarithmic, single or continuous. Single sweeps can be triggered from the front panel, the trigger input, or the digital interfaces.
A sweep marker is provided that is adjustable whilst sweep is running. The markers can provide a visual indication of frequency points on a ‘scope or chart recorder.

Gated

The Gated mode turns the output signal On when the gating signal is high and Off when it is low. The gating source can be the front panel key, trigger input socket, or bus interface signal.

External Amplitude Modulation is available for all waveforms via the VCA input.

FSK

Frequency Shift Keying provides phase coherent switching between two selected frequencies at a rate defined by the switching signal source. The switching source can be the front panel key, internal trigger generator, trigger input socket, or bus interface signal.

Tone Switching

The generator can be set to switch between a number of different frequencies in response to a trigger signal. Up to 16 frequencies can be defined. The tone is output while the trigger signal is true, and stops (after completion of a full cycle) when the trigger signal is false. The next tone is output when the trigger signal goes true again..

SPECIFICATIONS

FREQUENCY

All waveforms are derived from a crystal clock using Direct Digital Synthesis.

Frequency Range: 1mHz to 20MHz (except triangle)
Resolution: 6 digits or 1mHz
Accuracy: <±10ppm for 1 year, 18oC to 28oC
Tempco.: Typically <1ppm/oC outside of 18oC to 28oC

WAVEFORMS

Sinewave

Range: 1mHz to 20MHz
Resolution: 6 digits or 1mHz
Distortion: <0.3% THD to 20kHz (typically 0.1%), <-45dBc to 300kHz, <-35dBc to 20MHz (typically <-40dBc)
Spurii: Non harmonically related spurii <-55dBc to 1MHz, <(-55dBc + 6dB/octave) 1MHz to 20MHz
Output Level: 5mV to 20V pk-pk from 50 Ohms

Squarewave

Range: 1mHz to 20MHz
Resolution: 6 digits or 1mHz
Symmetry: variable 20% to 80% in 1% steps
Aberrations: <5% + 2mV
Rise & Fall Times: <22ns
Output Level: 5mV to 20V pk-pk from 50Ohms

Triangle

Range: 1mHz to 1MHz
Resolution: 6 digits or 1mHz
Linearity error: <0.5% to 100kHz
Output Level: 5mV to 20V pk-pk from 50 Ohms

Positive and Negative Pulse

Range: 1mHz to 20MHz
Resolution: 6 digits or 1mHz
Symmetry: variable 20% to 80% in 1% steps
Aberrations: <5% + 2mV
Rise & Fall Times: <22ns
Output Level: 2.5mV to 10V pk-pk from 50 Ohms positive or negative only pulses with respect to the DC Offset baseline

MODULATION MODES

Continuous

Continuous cycles of the selected waveform are output at the selected frequency.

Gated

Non phase-coherent signal keying - output is On while Gate signal is high and Off while low.

Carrier frequency: From 0.1Hz to 20MHz
Carrier waveforms: All
Trigger rep. rate: dc to 100kHz external, dc to 5kHz internal
Gate source: Front panel MAN TRIG key, Internal Gate Generator, TRIG/GATE input, or Remote Interface

Sweep

Carrier waveforms: All
Sweep Mode: Linear or logarithmic, single or continuous
Sweep Width: 0.2Hz to 20MHz. Phase continuous. Independent setting of the start and stop frequency.
Sweep Time: 50ms to 999s (3 digit resolution)
Markers: Marker variable during sweep. Available at the AUX OUT socket
Sweep Trigger source: The sweep may be free run or triggered from: front panel MAN TRIG key, TRIG/GATE input, or Remote Interface

Amplitude Modulation

Carrier frequency: 1mHz to 20MHz
Carrier waveforms: All
Modulation source: VCA IN socket

Frequency Shift Keying (FSK)

Phase coherent switching between two frequencies at a rate defined by the switching signal source.

Carrier frequency: 1Hz to 20MHz
Carrier waveforms: All
Switch repetition rate: dc to 5kHz (internal), dc to 1MHz (external)
Switching signal source: Front panel MAN TRIG key, Internal Trigger Generator, TRIG/GATE input, or Remote Interface

Tone

The tone is output while the trigger signal is true, and stops (after completion of a full cycle) when the trigger signal is false. The next tone is output when the trigger signal goes true again.

Carrier waveforms: All
Frequency list: Up to 16 frequencies between1Hz and 20MHz
Min. switching time: 1ms per tone
Switching source: IFront panel MAN TRIG key, Internal Trigger Generator, TRIG/GATE input, or Remote Interface

Internal Trigger/Gate Generator

Period: 0.2ms to 999s (resolution 0.2 ms)
Waveform: Square wave (1:1 duty cycle)

MAIN OUTPUT

Output Impedance: 50 Ohms or 600 Ohms switchable
Amplitude: 5mV to 20V pk-pk open circuit (2.5mV to 10V into 50 Ohms).
Output can be specified as V-HiZ (open circuit value) or V (potential difference) in pk-pk, RMS or dBm. Note that in positive or negative Pulse modes the amplitude range is 2.5mV to 10V pk-pk O/C.
Accuracy: ±3% ±1mV at 1kHz into 50 Ohms/600 Ohms
Flatness: ±0.2dB to 500kHz; ±1dB to 20MHz
DC Offset: ±10V from 50 Ohms/600 Ohms. DC offset plus signal peak limited to ±10V. Accuracy ±3% ±10mV
Resolution: 3 digits for both amplitude and offset

AUXILIARY OUTPUT

Multi-function output user definable to be any of the following:
Waveform Sync: Outputs a 50% duty cycle squarewave at the main waveform frequency
Trigger Out: Outputs the current trigger signal
Sweep Sync: Output a trigger signal at the start of sweep (for synchronising an oscilloscope or chart recorder). Can additionally output a sweep marker.
Signal Levels: Logic levels of <0.8V and >3V. Sweep Sync is a 3 level waveform, low at start of sweep, high at end of sweep, with a narrow 1V pulse at the marker point

INPUTS

Ext Trig/Gate

Frequency Range: DC to 1MHz for FSK; DC to 100kHz for Gate; DC to 2.5kHz for Tone and Sweep
Signal Range: Nominal TTL level threshold; maximum input ±10V
Min. Pulse Width: 100ns for Gate/FSK; 0.2ms for Sweep and Tone
Input Impedance: Typically 10k Ohms

VCA In

Frequency Range: DC - 100kHz
Signal Range: 2.5V for 100% level change at maximum output
Input Impedance: Typically 6k Ohms

INTERFACES

Full remote control facilities are available through the RS232 or USB interfaces.

RS232: Variable Baud rate (19200 max), 9-pin D-connector. As well as operating in a conventional RS-232 mode the interface can be operated in addressable mode whereby up to 32 instruments can be addressed from one RS-232 port
USB: Standard USB hardware connection. Conforming USB 1.1

GENERAL

Display: 20 character x 4 row alphanumeric LCD
Data Entry: Keyboard selection of mode, waveform etc.; value entry direct by numeric keys or by rotary control.
Stored Settings: Up to 9 complete instrument set-ups may be stored in battery-backed memory.
Size: 260(W) x 88(H) x 235(D) mm
Weight: 2kg (4.5lb)
Power: 100V, 110-120V or 220-240V ±10% 50/60Hz, adjustable internally. 40VA max. Installation Category II.
Operating Range: +5oC to 40oC, 20-80% RH
Storage Range: -20oC to +60oC
Environmental: Indoor use at altitudes up to 2000m, Pollution Degree 2
Safety: Complies with EN6010-1
EMC: Complies with EN61326

Thurlby Thandar Instruments Ltd. operates a policy of continuous development and reserves the right to alter specifications
without prior notice.

Thurlby Thandar Instruments Limited
Glebe Road, Huntingdon, Cambridgeshire PE29 7DR
Tel: 01480 412451 Fax: 01480 450409 Web: www.tti.co.uk Email: sales@tti.co.uk