The Model 745T Digital Delay Generator (DDG) offers the world's leading performance in a benchtop timing instrument. Twenty-five years ago, our Model 7095 Digital Delay Generator dramatically advanced research with jitter below 25 ps. Now, with all the features of a modern DDG, the Model 745T gives users incredible performance at a fraction of the cost. The Model 745T offers 4 precision delay channels from the front panel (output rise time less than 2 ns) with an additional 4-channel option on the rear panel (output rise time less than 5 ns). The Model 745T synchronizes to an external clock at 10 MHz or 80 MHz or custom frequency between 10 MHz and 80 MHz making the unit ideal for a broad range of applications that require short time domain delays.
The Clock In Connector and Clock Out Connector, are located on the rear panel of the instrument. A convenient Ethernet interface on the rear panel, allows remote control of the instrument. Berkeley Nucleonics' DDG-MUC software controls up to eight instruments (64 Channels). Alternatively, you may use the LabVIEW driver or the embedded web interface for ease of set up and control. The control software and LabVIEW drivers are included with the Model 745T at no additional cost.
Because many industries are now moving away from locally installed software packages, we have embedded a control interface in the Model 745T instrument. This also allows all parameters to be controlled by any PC, Mac or Linux system with a web browser. All you have to do is type in the unit's IP address into the browser after connecting a cable from the Ethernet port to your computer or network. A USB port is also available if LAN port cannot be used. Ethernet ports allow the user to use the web interface or sends and receives SCPI commands while the USB is SCPI . This is ideal for laboratories where you may need to move the delay generator to different locations.
Overview
Quick Specs |
Applications |
|
|
The Model 745T 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 synched 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
Back of Model 745T
The Model 745T Digital Delay Generator offers users several options for triggering timing channels: External, Internal, and Remotely (Remote trigger: only asynchronous Single-Shot). Externally trigger on the positive or negative slope of your trigger signal and select a level from 0.1 V to 5.0 V. Two internal trigger generators are adjustable from 0.25 Hz to 1 MHz in 1 Hz increments (note: it's possible to set the period by step of 5 ns as well, the range is then 1 µs to 4 s by step of 5 ns). These internal rep rate generators may be started by front panel pushbutton or remotely via your software interface. Either trigger mode may be set as one-shot or repetitive.
BURST MODE, for instance: pulse number 2 to 216-1, period 1000 ns to 1 s (depending on the trigger rate)
TRIGGER PRESCALER, for instance: prescaler value applied to the external trigger goes from 1 to 216-1
GATE MODE, for instance: can be set to General or individual channel
*See the user manual for more details.
The Model 745T Digital Delay Generator is housed in a compact design. The packaging dimensions are of 8.5" X 9.6" x 5.3". 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 for many channels packed into a small space on a bench or in a rack system. Berkeley Nucleonics offers a variety of custom packaging options as well. For even tighter space constraints, ask about a cPCI card-level version of the Model 745T or a custom enclosure design. Multi-instrument applications may find that operating from a single master clock may be useful. The standard benchtop package can be mounted with one or two instruments in a 19" rack.
On the front panel there are four standard Outputs, one external Trigger Input, and one Gate Input. Optionally, four more Outputs can be available on the front panel as well (total eight channel outputs) On the rear panel, there are Clock In, Clock Out, T0, and Auxiliary connectors.
Rise times below 1 nanosecond and Pulse Widths down to 10 nanoseconds are achieved by Channel Grouping. In this example, we group Channel 1 + Channel 2. The jitter is below 5 picoseconds and the delay and width resolution are both 250 femtoseconds. Contact the customer support for special output requirements.
| Internal Rate Generator | Two Independent Timers, 0.25 Hz to 1 MHz |
| External Trigger | 1 Trigger Input
Positive or Negative slope Minimum trigger delay < 65 ns Software Asynchronous Single Shot |
| Control | Front Panel or Remote (Ethernet or USB) |
| Clock Input | Standard 10 MHz and 80 MHz *contact factory for custom clock input frequency |
| Number of Outputs | Four (A to D) plus T0 [Standard] Eight (A to H) plus T0 *OPTIONAL |
| Amplitude | T0: 5 V into 50 Ω [Fixed] A to D: 2 V to 5 V into 50 Ω [Adjustable] E to H: 2 V to 5 V into 50 Ω [Adjustable] *OPTIONAL |
| Transition Time |
Rise: < 2 ns Fall: < 2 ns |
| Pulse Width | T0: 100 ns to 100 µs A to D: 100 ns to 100 µs E to H: 10 ns to 25 us *OPTIONAL |
| Delay Range | 0 ps to 20 seconds |
| Delay Resolution | A to D: 1 ps E to H: 1 ns |
| RMS Jitter | 25 ps + delay x 10e-8 (T0 to any output) |
| Accuracy | < 250 ps + delay x 10e-8 |
| Clock Output | 10 MHz [Square ~ +7 dBm] |
| Time Base | 0.05 ppm stability |
| Connector | BNC |
| Interface Control | Front-panel, LAN ( Internal Webpage or SCPI) |
| Software | Web Browser (Firefox, Chrome, Internet Explorer) |
| Size | Rack 19", 2U, D = 300 mm |
| Power | 90 to 220 VAC / 0.5 A |
| Shippping Dimensions | 22x9x17" |
| Shipping Weight | 20 lbs |
Downloadable resources such as datasheets, firmware, software, drivers and products manuals. Alternatively, you can browse resources directly by visiting our downloads page.
• Product Datasheets
• Product Firmware
• Product Software and Drivers
• Product Manuals
Media
Price List
Price lists are available to our registered users. To view pricing for this and other products, please log in or create a free account.
