1Overview
The PVX-4141 is a precision high voltage pulse generator from the Directed Energy Division of Berkeley Nucleonics. Using an externally supplied source up to 3,500 V, it produces fast, flat pulse waveforms optimized for high impedance capacitive loads. That suits it to driving extraction grids and deflection plates for the electrostatic modulation of particle beams in time-of-flight mass spectrometers and accelerators.
The same robust design serves a wide range of pulsing and gating tasks. Typical loads include power tube grids, Pockels cells and Q-switches, acoustic transducers, microchannel plates, photomultiplier tubes, and image intensifiers. The exceptional pulse fidelity of the PVX-4141, together with jitter below 200 ps, optimizes the performance of any system in which it is used.
The instrument is fully self-contained. All control and protection logic, support power, energy storage, and the output network are built in. It connects directly to the load and does not need series or shunt resistors, an impedance-matching network, or an external capacitor bank. To run, it needs a user-supplied TTL gate signal, a high voltage DC source, and an optional second supply when the output is biased away from ground.
2How It Works
The PVX-4141 is a direct-coupled, air-cooled, solid-state half-bridge, often called a totem-pole output stage. Two high voltage switches sit in series between a user-supplied high rail (VHigh) and low rail (VLow). The gate decides which rail is connected to the output. If the unit is enabled and the gate is high, VHigh is switched to the output; when the gate is low, VLow is switched to the output. The pulse amplitude is therefore set by the difference between the two supply voltages, and the pulse width and repetition rate are set by the gate.
Driving the output from both rails gives flexible polarity. With VLow at ground, the unit produces positive pulses from ground to +3,500 V. With VHigh at ground, it produces negative pulses from ground to −3,500 V. To make a negative-going pulse from a normally-high baseline, invert the gate so the input sits high until the unit is pulsed; when the gate goes low, VLow connects to the output and the result is a negative-going pulse. The output can also be offset from ground by setting both supplies, anywhere from −3,500 V to +3,500 V, with a maximum supply differential of 3,500 V.
The totem-pole topology gives equally fast rise and fall times, low power dissipation, and virtually no overshoot, undershoot, or ringing. Over-current detection and shut-down circuitry protect the generator against arcs and shorts in the load or the interconnect cable.
3Specifications
All output specifications are measured into a 50 pF load connected with 6 ft (~1.8 m) of RG-59 (75 Ω) coaxial cable, at 3,500 V output. The PVX-4141 can drive loads from a few picofarads to several hundred picofarads, limited by its maximum power dissipation. It can also drive resistive or inductive loads within limits; contact Berkeley Nucleonics for application assistance.
| Pulse characteristics | Specification |
|---|---|
| Output voltage range | 0 V to ±3,500 V (VHigh − VLow), controlled by power supply input voltages |
| Pulse rise/fall time | ≤25 ns (50 pF load) |
| Pulse width | 60 ns to DC, controlled by input gate |
| Frequency range | Single-shot to 30 kHz at 3,500 V continuous output, controlled by input gate |
| Max. average power | 100 W (VHigh + VLow) |
| Max. duty cycle | Continuous |
| Droop | <1% |
| Over/undershoot | <5% |
| Throughput delay | 120 ns typical |
| Jitter | <200 ps shot-to-shot |
| Output connector | SHV, rear panel, with 6 ft (~1.8 m) RG-59 (75 Ω) coaxial cable |
| Input DC voltage | Specification |
|---|---|
| +VIN (VHigh) absolute max. | +3,500 V |
| +VIN (VHigh) absolute min. | −3,500 V |
| +VIN (VHigh) relative max. | +3,500 V over VLow voltage |
| +VIN (VHigh) relative min. | +0 V over VLow voltage |
| −VIN (VLow) absolute max. | +3,500 V |
| −VIN (VLow) absolute min. | −3,500 V (only needed when biasing the output) |
| HV input DC connectors | SHV, rear panel (one each for +VIN and −VIN) |
| Gate, monitors & general | Specification |
|---|---|
| Gate source & connector | TTL into 50 Ω, front-panel BNC |
| Voltage monitor | 1000:1 into 1 MΩ, front-panel BNC |
| Current monitor | 10 A/V into 50 Ω, front-panel BNC |
| Voltage requirements | 100–120 VAC ±10% or 220–240 VAC ±10% |
| Line frequency | 50–60 Hz |
| AC connector type | NEMA C-14 |
| Size (H × W × D) | 13.2 × 43.5 × 33.0 cm, standard with 48.3 cm rack ears |
| Weight | 8.2 kg |
| Operating temperature | 15 °C to 35 °C |
4Front Panel & Monitoring
Front-panel indicator LEDs report the state of the pulse generator at a glance: output enabled, over-current, control error, gated, and power. Two instrument-quality monitor outputs sit on the front panel. The voltage monitor scales the output 1000:1 into 1 MΩ, and the current monitor reports 10 A per volt into 50 Ω. Together they let an engineer view the real-time output voltage and current waveforms on a standard oscilloscope, without a high voltage scope probe.
Power and enable controls are on the front panel. The over-current circuit shuts the output down on a fault from an arc or short, protecting both the pulser and the load. High voltage input and output connections are on the rear panel to keep the operator side of the instrument at low voltage.
5Remote & Gate Control
Pulse timing is driven by the gate. The gate input accepts a user-supplied TTL signal into 50 Ω on a front-panel BNC connector, and it sets both the pulse width and the repetition rate. Output amplitude is set separately by the user-supplied high voltage DC supplies, so timing and amplitude are controlled independently.
The PVX-4141 can also be operated through a 15-pin DSUB remote control connector on the rear panel. The control pins (9, 10, 11, 12, 13) are internally pulled high. For remote operation, pull the REMOTE pin low; this disables the front-panel ENABLE switch to prevent local operation. The remote ENABLE, INTERLOCK, INVERT, and AUTO RESET inputs stay active regardless of the REMOTE state. Momentarily pulling ENABLE low enables the unit, or clears a fault, on the rising edge of that signal. Pulling the INVERT pin low inverts the gate internally, so the output pulse is inverted relative to the input gate.
The status pins (6, 7, 8, 14, 15) mirror the front-panel LEDs as open-drain outputs and require an external pull-up resistor (100 kΩ) to a source below 24 VDC.
6Applications
- Time-of-flight mass spectrometry. Precision pulsing of extraction grids and deflection plates for electrostatic modulation of ion beams. The fast edges and low jitter make this the flagship application.
- Accelerators and beam handling. Deflecting, gating, and kicking charged-particle beams.
- Electro-optics. Driving Pockels cells and Q-switches in laser cavities where fast, low-jitter edges matter.
- Detector gating. Gating microchannel plates, photomultiplier tubes, and image intensifiers.
- Tube and transducer drive. Pulsing or gating power tube grids and acoustic transducers.
7Ordering Information
| Model | Description |
|---|---|
| PVX-4141 System | 3,500 V high voltage pulse generator, ≤25 ns rise/fall, 60 ns to DC pulse width, single-shot to 30 kHz, <200 ps jitter, with voltage and current monitors and 15-pin remote control |
The PVX-4141 requires a user-supplied high voltage DC source up to 3,500 V and a TTL gate. A second DC supply is needed only when the output is biased away from ground. Berkeley Nucleonics can advise on supply sizing from the load capacitance, pulse voltage, and repetition rate.
Contact
For a quote, configuration help, or application support, reach the Berkeley Nucleonics team.
Email: info@berkeleynucleonics.com
Phone: 800-234-7858