GFT745, 250fs Digital Delay Generator
GFT745, 20 channel Pulse & Delay Generator


  • 4 delay channels ( 8 in option)
    • 250 femtosecond time resolution
    • Down to 5 ps jitter (internal trigger)
    • 25 ps jitter (external trigger)
  • Pulse output ;  5 V ,1 ns rise time into 50 Ω
  • Independent trigger rates for each channel
  • 5 trigger modes: repetitive, single shot, gate, burst, prescaler
  • Selectable clock inputs (10M Hz to 80 MHz, user may specify a value to the nearest 100 kHz)
  • Front panel, Ethernet and Embedded Browser, USB control
  • Up to 64 Channels Displayed on 1 GUI
  • Rack mount kit in otion


The GFT745 Digital Delay Generator (DDG) offers the world’s leading performance in a benchtop timing instrument. Now, with all the features of a modern DDG, the GFT745 gives users incredible performance at a fraction of the cost. The GFT745 offers 4 precision delay channels from the front panel with an additional 4 channel option on the rear panel. The output risetime is 1 ns and the user may specify the frequency of the external clock. The GFT745 syncs to an external clock between 10 MHz and 80 MHz making the unit ideal for a broad range of applications requiring short time domain delays.

The optional channels (outputs for Ch 5 – 8) along with the Gate Out Connector and Clock Out Connector, are located on the rear panel of the instrument. A convenient Ethernet interface on the rear panel, allows control of the instrument. The control software and Labview drivers are included with the Model 745 at no additional cost.

Because many industries are now moving away from locally installed software packages, we have embedded a control interface in the GFT745 instrument. This also allows all parameters to be controlled by any PC with a browser. You will need to enter the unit’s IP address into the browser after connecting a cable from the Ethernet port to your computer network. The instrument will provide an IP address on the front panel display and the browser will open a virtual control panel. This is ideal for laboratories where you may need to move the delay generator to different locations.


The GFT745 virtually eliminates triggering indeterminacy by having a clock that is now in phase with an External Trigger. The resulting external trigger jitter is far better than instruments whose outputs are sync’ed to an internal free-running clock. See the datasheet for exact jitter specification and additional details on “Achieving 2 Picoseconds Jitter in a DDG”. The following chart indicates typical jitter at various delays:

  • Internal Trigger, Delays < 100 ns: 2 picoseconds
  • Internal Trigger, Delays > 100 ns: 15 picoseconds + timebase
  • External Trigger, Delays < 100 ns: 25 picoseconds
  • External Trigger, Delays > 100 nS: 25 picoseconds + timebase


The GFT745 Digital Delay Generator offers users several options for triggering timing channels: External, Internal and Remotely. Externally trigger on the positive or negative slope of your trigger signal and select a level from 0.1 V to 5.0 V. An internal trigger generator is adjustable from 1 Hz to 50 kHz in 1 Hz increments. This internal rep rate generator may be started by front panel pushbutton or remotely via your software interface. Either trigger mode may be set in one-shot or repetitive.


The GFT745 Digital Delay Generator is housed in a compact design. The packaging dimensions are of 8.5″ X 9.6″ x 5.2″. The convenient design allows two instruments (up to 16 channels) to fit side by side in a 19″ rack mount (sold separately). This small footprint allows many channels to be packed into a small space on a bench or in a rack system. Greenfield Technology can offer a variety of custom packaging options as well. For even tighter space constraints, ask about a cPCI card-level version of the GFT745 or a custom enclosure design. Multi-instrument applications may find operating from a single master clock useful. The standard benchmount package can be mounted in a 19″ rack with one or two instruments.


On the front panel there are four standard Outputs and one external Trigger Input. On the rear panel, there is a Clock Input and a To Output. There are 4 optional outputs on the rear panel in addition to a Gate In and Clock Out connector.