QBU-series consists of several Pockels cell drivers that differ with output voltage range, max 6.0 kV bipolar (see also How to order? section). Please, note that by bipolar device an output pulse voltage U is formed by applying +U/2 to positive output wire and –U/2 to negative.
QBU-series is specially designed to control Pockels cells by applying a fast switching high voltage. The modules require +24 V DC power supply and pulse generator to set an operating frequency and pulse width. An output voltage level can be programmed in working range by user either manually (through onboard configuration trimpot) or remotely (applying a DC voltage to the respective pin).
Triggering by an external low voltage arbitrary TTL signal allows modules to work in next scenarios:
- push-up (= normally off scheme), when a base voltage level equals to zero
- pull-down (= normally on scheme), when pulses from base bias voltage to ground are generated
- user-defined scheme, with arbitrary width and frequency of pulses.

QBU-series is based on MOSFET technology and offers high repetition rates and fast transition time (< 15 ns) for both pulse edges.
Performance
For instance, QBU-5020 kept cool enough and running with proper load (Pockels cell with 5‑7 pF capacitance plus 30-50 cm connective cable) has typical performance as below:
(*) The values are approximate, exact performance depends on actual load capacitance and cooling conditions.
In burst mode (i.e. for short term operations) the performance increases approximately twice and exceeds 100 kHz at low operating voltages and low load capacitances.
The performance deteriorates for higher load capacitance.
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Compact driver, up to 4 kV |
Encased driver |
Up to 10 kV output |
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Output:
output is triggered by an arbitrary external TTL signal
Voltage, high level
regulated, up to 6 kV
1
Voltage, low level
fixed, 0 V
Maximal repetition rate
up to 100 kHz and higher (load and voltage dependant, see also Performance section)
1
Rise time (fall time)
2
< 15 ns (~10 ns typ.) @ load < 11 pF
< 20 ns @ load < 23 pF
Jitter
10 ns (1 ns in LJ-modification)
Delay time
1 us (100 ns in LJ-modification)
Load capacitance
up to 0.5 nF
1
Environment:
Operation temperature
+10 … +40 °C (wider temperature range is available on request)
Storage temperature
-20 … +60 °C
Humidity
0 ... 90%, non-condensing
Other:
Size (LxWxH)
130x80x25 mm
1)
these parameters aren't indepenent and cannot achieve their maximum at the same time
2)
10-90% level
Voltage modifications
2.4-6.0 kV high voltage adjustment range
2.0-5.0 kV high voltage adjustment range
1.6-4.0 kV high voltage adjustment range
1.2-3.0 kV high voltage adjustment range
0.8-2.0 kV high voltage adjustment range
0.4-1.0 kV high voltage adjustment range
(*) Other output voltages are available on request
Example
2.0-5.0 kV high voltage adjustment range
Low jitter option