This pulse generator is designed to provide precise timing signals with flexible pulse width options. Powered by two input voltages of 5V and 3.3V, it generates a single pulse triggered on the rising edge of the TRIG pin. The pulse amplitude is dependent on the load, offering 1.65V into a 50-ohm load or 3.3V in a high-impedance (Hi-Z) load.
The pulse width is programmable and can be selected from four options, each equally spaced by a standard width, ensuring versatility for a range of applications. There are two variants of the board available to accommodate different needs: a 5 ns variant, and a 10 ns variant, providing pulse widths as low as 5 ns or 10 ns, respectively.
This pulse generator is ideal for testing, signal processing, and other applications requiring high-speed, precise pulse generation.
Features
- Operates off 5 V, and 3.3 V supply rails
- Note: Both rails are required for proper functionality
- Pulse amplitude is 1.65 V into 50 ohm or 3.3 V into Hi-Z
- Four selectable pulse widths:
- 5 ns, 10 ns, 15 ns, and 20 for the 5 ns variant
- 10 ns, 20 ns, 30 ns, and 40 for the 10 ns variant
- MMCX output connector
- On-board TRIG buffer to relax input rise-time requirements
Use Cases
- Time Domain Reflectometry (TDR)
- Ultra-Wideband (UWB) Radar
- Optical driver
Specifications
Absolute Maximum
| Parameter | Min | Max | Unit |
|---|---|---|---|
| 5V | -0.5 | 6.5 | V |
| 3V3 | -0.5 | 4.6 | V |
| TRIG | 0 | 25 | MHz |
Recommended Operation
| Parameter | Min | Typ. | Max | Unit |
|---|---|---|---|---|
| 5V | 4.8 | 5.0 | 5.2 | V |
| 3V3 | 3.2 | 3.3 | 3.4 | V |
| VIH (2) | 2.4 | — | 3.4 | V |
| VIL (2) | 0.0 | — | 0.8 | V |
| VOH HI-Z 50 | 2.2 1.1 | — | 3V3 3V3/2 | V |
| VOL HI-Z 50 | 0.0 0.0 | — | 0.56 0.28 | V |
- All parts are rated for -40 to 85 °C
- Specification applies to EN_L, S0, S1, TRIG, and HOLD
Operation
The pulse generator functions by comparing a reference signal to a delayed signal. The resulting waveform is a narrow pulse of just a few nanoseconds.
| EN_L | S0 | S1 | HOLD | OUT |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 3x PW |
| 0 | 0 | 1 | 0 | 4x PW |
| 0 | 1 | 0 | 0 | 1x PW |
| 0 | 1 | 1 | 0 | 2x PW |
| 0 | X | X | 1 | 1 |
| 1 | X | X | Y | Y |
A single pulse is triggered on the rising edge of the TRIG pin. The pulse width is selected based on the table above. The pulse amplitude is dependent on the load, offering 1.65V into a 50-ohm load or 3.3V in a high-impedance (Hi-Z) load.
Recommended Footprint
- Use 120 mil x 120 mil pads for each pin
- All un-labeled pins must be connected to GND
- It is recommended to have copper cutout on the mounting surface to avoid potential short-circuits from vias. The boards are spec’d to have their vias tented, but accidental exposure can happen. This is a pre-cautionary step.