CF8000 Octal Constant Fraction Discriminator

Specifications

PERFORMANCE

WALK  <±250 ps from -50 mV to -5 V for a pulse rise time of 1 ns, a pulse width of 10 ns, a 2-ns delay, and the threshold set at minimum.

CONSTANT-FRACTION RATIO  0.4.

INPUT/OUTPUT RATE  20 MHz maximum.

PULSE/PAIR RESOLUTION  <50 ns.

TRANSMISSION DELAY
"A" Outputs  13 ns, typically.
"B" Outputs  16 ns, typically.

THRESHOLD TEMPERATURE SENSITIVITY  <±100 ppm/°C from 0 to +50°C.

CONTROLS

THRESHOLD CONTROL (TH)  20-turn front-panel screwdriver adjustment for each discriminator channel; nominally variable from -30 mV to -1 V.

THRESHOLD MONITOR  Front-panel test point located to the right of the threshold control. Outputs actual threshold voltage.

WIDTH ADJUSTMENTS (TA and TB)  20-turn front-panel screwdriver adjustments to set the width of the "A" and "B" Fast-NIM logic outputs. Adjustment range:  nominally 20-200 ns.

DELAY  Internal PCB jumper setting allows the proper shaping delay to be selected. Five possible positions:  2, 4, 6, 8, or 10 ns. Other delays available on order.

INPUTS

INPUTS  Front-panel LEMO connector for each channel.

INPUT RANGE  0 to -5 V.

PROTECTED TO -100 V for pulse duty cycles <0.05%.

IMPEDANCE  50 W, dc-coupled.

INHIBIT INPUT  Front-panel LEMO connector accepts negative Fast-NIM signal. Active-low signal disables "B" logic outputs.

OUTPUTS

"A" LOGIC OUTPUTS (A)  Eight front-panel LEMO connectors provide adjustable-width, updating Fast-NIM logic signals for inputs above threshold setting.
Amplitude  -0.7 V minimum with 50-W load.
Width  Settable from nominally 20-200 ns by 20-turn front-panel screwdriver adjustment (TA).

"B" LOGIC OUTPUTS (B)  Sixteen front-panel LEMO connectors provide adjustable-width, updating Fast-NIM logic signals for inputs above threshold setting.
Amplitude  -0.7 V minimum with 50-W load.
Width  Settable from nominally 20-200 ns by 20-turn front-panel screwdriver adjustment (TB).

MULTIPLICITY OUTPUT (M)  Front-panel LEMO connector provides a pulse signal with amplitude proportional to the number of "B" logic outputs active at any instant.
Amplitude Range  Nominally 0 to -0.5 V with 50-W load.

OR OUTPUT (OR)  Front-panel LEMO connector provides logical OR of all "B" logic outputs. Negative Fast-NIM signal.

ANALOG SUM OUTPUT (S) A front-panel LEMO connector provides an analog summation of all input channels divided by an attenuation factor of approximately 16, with a 50-W load.

ENERGY OUTPUTS  Eight, rear-panel LEMO connectors provide the buffered input signal from each channel.

ECL OUTPUTS  Rear-panel 2 x 8 differential ECL logic connector that provides and ECL version of the eight "B" outputs.
Line Impedance  112 W.

ELECTRICAL AND MECHANICAL

POWER REQUIRED  +12 V, 40 mA; -12 V, 40 mA; +6 V, 250 mA; -6 V, 1000 mA.

WEIGHT  1.5 kg (3.3 lbs).

DIMENSIONS  Standard single-width NIM module, 3.43 x 22.13 cm (1.35 x 8.714 in.) front panel per DOE/ER-0457T.

OPTIONAL ACCESSORIES

CFD-DELAY-5 ns  Delay plug-in for 1, 2, 3, 4, or 5-ns delay settings.

CFD-DELAY-10 ns  (Factory installed in the instrument)  Delay plug-in for 2, 4, 6, 8, or 10-ns delay settings.

CFD-DELAY-30 ns  Delay plug-in for 6, 12, 18, 24, or 30-ns delay settings.

CFD-DELAY-50 ns  Delay plug-in for 10, 20, 30, 40, or 50-ns delay settings.

ORDERING INFORMATION

Order eight delay options to populate all 8 discriminator channels.