280 Series Waveform Generators
A selection of universal waveform generators offering superior performance and excellent value
A selection of universal waveform generators offering superior performance and excellent value
These universal waveform generators combine many generators in one instrument. Their extensive signal simulation capabilities include arbitrary waveforms, function generator, pulse/pulse train generator, sweep generator, trigger generator, tone generator, and amplitude modulation source.
- Choice of 1, 2 and 4 independent or linked channels
- 40 MS/s max. sampling speed
- 16 MHz function generator
- 10 MHz pulse generator
- Pulse train pattern generator
- Arbitrary waveforms of up to 65 k points
- Powerful modulation capabilities
- Built-in trigger generators
- Waveform Manager Plus for Windows® software
- Multiple standard waveforms recalled from internal memory
- RS-232 and GPIB interfaces
The 281, 282, and 284 Waveform Generators use Direct Digital Synthesis techniques as well as variable clock sampling technology to provide a fully featured programmable function and arbitrary waveform capability. The 281, 282 and 284 are 40 MS/s arbitrary waveforom generators with one, two, and four channels, respectively.
Waveform Manager Plus Software provides all the features needed for creation, manipulation and management of arbitrary waveforms within a single Windows-based program.
Single or multiple channels:
The 28x series comprises a single channel model (281), two channel (282) and 4 channel (284). Each channel can be operated fully independently, or multiple channels can be linked using simple or complex relationships.
Waveforms
Standard waveforms include: sine, square, triangle, dc, positive ramp, negative ramp, sine(x)/x, pulse, pulse train, cosine, haversine and havercosine. Output frequency range is 0.1 mHz to 16 MHz for sine and square and up to 100 kHz for triangle, ramps and sine(x)/x. Rise time for pulse is < 25 ns with a period range of 100 ns to 100 s. Output amplitude range can be adjusted from 2.5 mV to 10 V pk-pk into 50 Ω.
Versatile pulse generator capabilities:
Each channel can generate not just pulses but complex pulse trains. A pattern of up to 10 pulses can be quickly defined with each pulse having its own amplitude, width and delay. The whole pulse train pattern can then be replayed at a user defined repetition rate. Where variable rise time pulses are required, the full arbitrary function can be used.
Arbitrary capability unmatched at this price:
The 280 series are highly sophisticated 12-bit arbitrary generators capable of recreating virtually any waveform. True variable clock architecture is used with clock speeds between 0.1Hz and 40 MHz. This architecture avoids the clock jitter associated with DDS arbitrary generators and permits waveform linking, looping and sequencing. Waveforms may be defined with up to 4096 vertical points and from 4 to 65,536 horizontal points. Arbitrary waveforms may be replayed at a specified waveform frequency, period or sample rate. Up to 100 user-defined waveforms can be stored within the instrument’s 256K of nonvolatile memory.
Linked-sequence operation:
Up to sixteen arbitrary waveforms may be linked in a sequence. Each waveform can have a loop count of up to 32,768 and the whole sequence can be run continuously or repeated more than a million times. For multi-channel models, waveforms on different channels can be ‘daisy chained’ and looped. By summing the channel outputs, up to 64 segments can be used to create highly complex waveforms.
Multi-channel phase locking:
Any number of channels can be phase locked with offsets defined to a resolution of 0.1 degree (or 360 degrees/waveform points for arbitrary waveforms). For applications requiring more than four channels, multiple generators can be phase locked. The 280 series also has the facility for phase locking to another generator.
Multi-channel Summing:
Waveform Summing sums the waveform from any channel into the next channel. Alternatively any number of channels can be summed with an external signal. This permits complex modulations to be created such as noise superimposition.
Inter-channel triggering and modulation:
Because any channel can be triggered by the previous or next channel, waveforms on different channels can be ‘daisy chained’ and looped. By summing the channel outputs, up to 64 segments can be used (32 segments for 282). A channel can be used to AM modulate or SCM modulate another channel.
Wide frequency sweep range:
All waveforms can be swept over their full frequency range at a rate variable between 30 milliseconds and 15 minutes. 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. Multiple channels can be swept simultaneously.
Amplitude modulation:
Amplitude Modulation and Suppressed Carrier Modulation are available for all waveforms. Any channel can be used to modulate another channel. Alternatively all channels can be modulated simultaneously via the modulation input.
Built-in trigger generator:
All waveforms are available as a triggered burst whereby each trigger edge will produce one burst of the carrier. Start and stop phase is fully variable. Both Triggered and Gated modes can be operated from the internal trigger generator, from an adjacent channel, an external source or a key press or remote command. The trigger generator signal is available as a separate output if required.
Tone switching:
The 280 series can provide triggered switching between up to 16 frequencies of standard or arbitrary waveforms. Tone switching modes can be gated, triggered or FSK using any trigger source. By summing two channels together it is possible to generate precise DTMF test signals.
Windows based waveform editing:
Each generator is supplied complete with sophisticated Windows based software for the creation, editing and management of waveforms. This powerful software can be used to create arbitrary waveforms from scratch using drawing tools, equations or both together. Real-world waveforms imported from DSOs or other sources can be modified and combined with other waveforms using editing functions. A library of ‘standard’ waveforms is included which can be used as ‘elements’ when creating or modifying waveforms. A powerful Equation Editor provides an array of mathematical functions including logarithmic and geometric operands. Waveform creation and editing can make use of drawing tools in combination with equations, insertion and manipulation. Multiple waveforms can be further combined using mathematical operators to create new waveforms.
Import from DSOs and other instruments:
The Windows software incorporates direct support for uploading waveforms from Tektronix digital oscilloscopes. A driver for LabWindows CVI from National Instruments is available which enables imports from other equipment to be achieved within the LabWindows environment.
Fully programmable:
via RS-232 or GPIB The 280 series incorporates both an RS-232 interface and a GPIB (IEEE-488) interface as standard. These can be used for loading arbitrary waveforms and for remote control of all instrument functions.
Specifications apply at 18-28 ºC after 30 minutes warm-up, at maximum output into 50 Ω.
Arbitrary Waveforms |
|
| Waveforms | Maximum waveform size is 65,536 points; minimum waveform size is 4 points. Up to 100 user defined waveforms may be stored in the 256 K point nonvolatile RAM. Waveforms can be defined by front panel editing controls or by downloading of waveform data via RS-232 or GPIB. |
| Waveform memory | 64 k points per channel |
| Vertical resolution | 12 bits |
| Sample clock | 100 mHz to 40 MHz |
| Resolution | 4 digits |
| Accuracy | ± 1 digit of setting |
| Sequencing | Up to 16 waveforms may be linked. Each waveform can have a loop count of up to 32,768. A sequence of waveforms can be looped up to 1,048,575 times or run continuously. |
| Output filter | Selectable between 16 MHz Elliptic, 10 MHz Elliptic, 10 MHz Bessel or none |
Standard Waveforms
All Waveforms |
|
| Accuracy | 10 ppm for 1 year |
| Temp. stability | Typically < 1 ppm/ºC. |
| Output level | 2.5 mV to 10 Vpp into 50 Ω |
Sine, Cosine, Haversine, Havercosine |
|
| Range | 0.1 mHz to 16 MHz |
| Resolution | 0.1 mHz or 7 digits |
| Harmonic distortion | < 0.1 % THD to 100 kHz; < –65 dBc to 20 kHz, < –50 dBc to 300 kHz, < –35 dBc to 10 MHz < –30 dBc to 16 MHz |
| Nonharmonic spurii | < –65 dBc to 1 MHz, < –65 dBc + 6 dB/octave 1 MHz to 16 MHz |
Square |
|
| Range | 1 mHz to 16 MHz |
| Resolution | 1 mHz (4 digits) |
| Accuracy | ± 1 digit of setting |
| Rise/fall times | < 25 ns |
Pulse and Pulse Train |
|
| Rise/fall times | < 25 ns |
| Period range | 100 ns to 100 s |
| Period resolution | 4 digit |
| Accuracy | ± 1 digit of setting |
| Delay range | –99.99 s to + 99.99 s |
| Delay resolution | 0.002 % of period or 25 ns, whichever is greater |
| Width range | 25 ns to 99.99 s |
| Width resolution | 0.002 % of period or 25 ns, whichever is greater |
Triangle |
|
| Range | 0.1 mHz to 100 kHz |
| Resolution | 0.1 mHz or 7 digits |
| Linearity error | < 0.1 % to 30 kHz |
| Ramps and Sin(x)/x | |
| Range | 0.1 mHz to 100 kHz |
| Resolution | 0.1 mHz (7 digits) |
| Linearity error | 0.1 % to 30 kHz |
Note: The pulse width and absolute value of the delay may not exceed the pulse period at any time. Repetition rate is set by the pulse train period.
Operating Modes |
|
| Continuous | Waveform runs continuously |
| Triggered Burst | Each active edge of the trigger signal will produce one burst of the waveform |
| Carrier waveforms | All standard and arbitrary |
| Max. Carrier Frequency | 40 Msamples/s for ARB and Sequence. 1 MHz or the maximum for the selected waveform. |
| Number of cycles | 1 to 1,048,575 |
| Trigger repetition | 0.005 Hz to 100 kHz internal dc to 1 MHz external |
| Trigger signal source | Internal from keyboard, previous channel, next channel or trigger generator. External from TRIG IN or remote interface. |
| Trigger start/stop phase | ± 360 ° settable with 0.1 ° resolution, subject to waveform frequency and type |
| Gated | Waveform will run while the Gate signal is true and stop while false |
| Carrier waveforms | All standard and arbitrary |
| Max. carrier frequency | 40 Msamples/s for ARB and Sequence. 1 MHz or the maximum for the selected waveform. |
| Number of cycles | 1 to 1,048,575 |
| Trigger repetition | 0.005 Hz to 100 kHz internal dc to 1 MHz external |
| Gate signal source | Internal from keyboard, previous channel, next channel or trigger generator. External from TRIG IN or remote interface. |
| Gate start/stop phase | ± 360 ° settable with 0.1 ° resolution, subject to waveform frequency and type |
| Sweep | Frequency sweep capability is provided for both standard and arbitrary waveforms. Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to perform the sweep. |
| Carrier waveforms | All standard and arbitrary except pulse, pulse train and sequence |
| Sweep mode | Linear or logarithmic, triggered or continuous |
| Sweep direction | Up, down, up/down or down/up |
| Sweep range | From 1 mHz to 16 MHz in one range. Phase continuous. Independent setting of the start and stop frequency. |
| Sweep time | 30 ms to 999 s |
| Marker | Variable during sweep |
| Sweep trigger source | The sweep may be free run or triggered from the following sources: Manually from keyboard. Externally from TRIG IN input or remote interface. |
| Sweep hold | Sweep can be held and restarted by the HOLD key |
| Multi channel sweep | Any number of channels may be swept simultaneously but the sweep parameters will be the same for all channels. Amplitude, Offset and Waveform can be set independently for each channel. |
| Tone Switching | Capability provided for both standard and arbitrary waveforms. Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to allow instantaneous frequency switching. |
| Carrier waveforms | All except pulse, pulse train and sequence |
| Frequency list | Up to 16 frequencies from 1 mHz to 10 MHz |
| Trigger repetition rate | 0.005 Hz to 100 kHz internal. DC to 1 MHz external. Usable repetition rate and waveform frequency depend on the tone switching mode. |
| Source | Internal from keyboard, previous channel, next channel or trigger generator. External from TRIG IN or remote interface. |
| Tone switching modes | |
| Gated | The tone is output while the trigger signal is true and stopped, at the end of the current waveform cycle, while the trigger signal is false. The next tone is output when the trigger signal is true again. |
| Triggered | The tone is output when the trigger signal goes true and the next tone is output, at the end of the current waveform cycle, when the trigger signal goes true again. |
| FSK | The tone is output when the trigger signal goes true and the next tone is output, immediately, when the trigger signal goes true again. Using 2 channels with their outputs summed together it is possible to generate DTMF test signals. |
| Trigger Generator | Internal source 0.005 Hz to 100 kHz square wave adjustable in 10 us steps. 3-digit resolution. Available for external use from any SYNCOUT socket. |
Outputs
Main Outputs – One for each channel |
|
| Output impedance | 50 Ω |
| Amplitude | 5 mV to 20 Vpp open circuit (2.5 mV to 10 Vpp into 50 Ω). Amplitude can be specified open circuit (hi Z) or into an assumed load of 50 Ω or 600 Ω Vpkpk, Vrms or dBm. |
| Amplitude accuracy | 2 % ± 1 mV at 1 kHz into 50 Ω |
| Amplitude flatness | ± 0.2 dB to 200 kHz; ± 1 dB to 10 MHz; ± 2.5 dB to 16 MHz |
| DC offset range | ± 10 V from 50 Ω. Offset plus signal peak limited to ± 10 V |
| DC offset accuracy | Typically 3 % ± 10 mV, unattenuated |
| Resolution | 3 digits or 1 mV for both amplitude and dc offset |
| Sync Out – One for each channel | Multifunction output user definable or automatically selected to be any of the following: |
| Waveform sync (all waveforms) | A square wave with 50 % duty cycle at the main waveform frequency, or a pulse coincident with the first few points of an arbitrary waveform |
| Position markers | Any point(s) on the waveform may have associated marker bit(s) set high or low |
| Burst done | Produces a pulse coincident with the last cycle of a burst. |
| Sequence sync | Produces a pulse coincident with the end of a waveform sequence. |
| Trigger | Selects the current trigger signal. Useful for synchronizing burst or gated signals. |
| Sweep sync | Outputs a pulse at the start of sweep to synchronize an oscilloscope or recorder. |
| Phase lock out | Used to phase lock two generators. Produces a positive edge at the 0 ° phase point. |
| Output signal level | TTL/CMOS logic levels from typically 50 Ω. |
| Cursor/marker out | Adjustable output pulse for use as a marker in sweep mode or as a cursor in arbitrary waveform editing mode. Can be used to modulate the Z axis of an oscilloscope or be displayed on a second ‘scope channel.
Output Signal Level: Adjustable from nominally 2 V to 14 V, normal or inverted; adjustable width as a cursor. |
| Output impedance | 600 Ω typical |
Inputs
Trig In |
|
| Frequency range | DC to 1 MHz |
| Signal range | Threshold nominally TTL level; maximum input ± 10 V |
| Min. pulse width | 50 ns, for Trigger/Gate; 50 us for Sweep mode |
| Polarity | Selectable as high/rising edge or low/falling edge |
| Input impedance | 10 kΩ |
Modulation In |
|
| Frequency range | DC to 100 kHz |
| VCA signal range | Approximately 1 V pkpk for 100 % level change at maximum output |
| SCM signal range | Approximately ± 1 V pk for maximum output |
| Input impedance | Typically 1 kΩ |
Sum In |
|
| Frequency range | DC to 8 MHz |
| Signal range | Approximately 2 V pk-pk input for 20 V pk-pk output |
| Input impedance | Typically 1 kΩ |
Hold |
|
| Hold | Holds an arbitrary waveform at its current position. A TTL low level or switch closure causes the waveform to stop at the current position and wait until a TTL high level or switch opening which allows the waveform to continue. The front panel MAN HOLD key or remote command may also be used to control the Hold function. While held the front panel MAN TRIG key or remote command may be used to return the waveform to the start. The Hold input may be enabled independently for each channel. |
| Input impedance | 10 kΩ |
Ref Clock In/Out |
|
| Set to input | Input for an external 10 MHz reference clock. TTL/CMOS threshold level. |
| Set to output | Buffered version of the internal 10 MHz clock. Output levels nominally 1 V and 4 V from 50 Ω |
| Set to phase lock | Used together with SYNC OUT on a master and TRIG IN on a slave to synchronise (phase lock) two separate generators. |
Inter-Channel Operation |
|
| Inter-Channel Modulation | The waveform from any channel may be used to Amplitude Modulate (AM) or Suppressed Carrier Modulate (SCM) the next channel. Alternatively any number of channels may be Modulated (AM or SCM) with the signal at the MODULATION input socket. |
| Carrier frequency | Entire range for selected waveform |
| Carrier waveforms | All standard and arbitrary waveforms |
| Modulation types: AM | Double sideband with carrier. SCM: Double sideband suppressed carrier |
| Modulation source | Internal from the previous channel. External from Modulation input socket. The external modulation signal may be applied to any number of channels simultaneously. |
Model Name |
Description |
|---|---|
| 281 | 1 Channel 40 MS/s Arbitrary Waveform Generator and Waveform Manager Plus Software |
| 282 | 2 Channel, 40 MS/s Arbitrary Waveform Generator and Waveform Manager Plus Software |
| 284 | 4 Channel, 40 MS/s Arbitrary Waveform Generator and Waveform Manager Plus Software |
