LeCroy 4416 16 Channel Programmable Discriminator, ECL

Model 4416 16-Channel Programmable Updating Discriminator

The new Model 4416 is a unique, high-speed multichannel discriminator designed to meet the exacting demands of modern high energy physics. It offers low cost and high density, very high speed with low complexity, local or remote programmability features, and self-testing capability.

Low Cost/High Density

The 4416 offers substantial savings over conventional quad or octal discriminators. Packaged 16 channels to a single-width CAMAC module, it not only costs less per channel, but also cuts down on rack space by at least a factor of four and decreases the cost of associated cabling and power supply hardware.

The unprecedented density of the 4416 is made possible through extensive hybridization, the use of a specially-designed "Lemo-type" input connector assembly, and the selection of CAMAC packaging. Use of the CAMAC standard permits high density by providing increased power with adequate cooling to maintain reliable operation.

High Speed/Low Complexity

The Model 4416 has been designed with 250 MHz updating operation and 200 MHz counting rate capability. This significant advance, made possible by LeCroy's new LD401 hybrid, results in low system deadtime and subsequent higher trigger efficiency. The two complementary ECL outputs of each 4416 channel are designed for use with inexpensive flat or individual cables, allowing fast and accurate system interconnections. The low parts count resulting from the elimination of the usual ECL-to-NIM conversion stage and from the inclusion of the timing stage in the LD401 hybrid yields low cost and high reliability. ECL outputs provide the convenience of compatibility with most large-scale in-house-designed trigger decision circuits, as well as with LeCroy's other Series 4000 programmable units. The output widths are adjustable from 5 to 40 nsec. Output widths up to 100 nsec are possible with restriction that minor output width modulation effects may occur if the input width and output width are equal.

Local or Remote Programmability

Use of the CAMAC standard provides the option of either local or remote programming and monitoring of the common threshold level. The threshold is adjustable via front-panel potentiometer or via CAMAC instructions to an internal 10-bit DAC, from -15 mV to greater than -1 volt. Accurate threshold monitoring is accomplished locally via a front-panel monitor point or remotely via CAMAC command and an internal ADC. The remote setting and reading capability provides the convenience of computer-controlled plateau measurements. For additional system flexibility, input masking is made possible by simultaneously inhibiting any combination of the 16 inputs via CAMAC command. This feature allows the user to generate or simulate any desired trigger configuration and perform complete point-to-point checks of the system electronics. A built-in test feature simulates an input signal for each channel upon receipt of either an F(25) command or a NIM-level signal applied to a Lemo-type rear-panel test input connector. This permits rapid, simultaneous testing of all enabled discriminator channels.

SPECIFICATIONS Model 4416 16-Channel Programmable Updating Discriminator

INPUT CHARACTERISTICS

Signal Inputs:

16, Lemo-type front-panel connectors, 50 Ohm +/- 2%. Protected to +/-5 A for 0.5 sec, clamping at +1 and -6 volts. Reflections < 4% for input pulses of 2 nsec risetime. Stability better than 0.2%/'C over 20' C to 60' C operating range offset +/-l mV. Threshold, -15 mV to -1023 mV +/-5% or +/-1.5 mV, whichever is greater, (common to all channels); front panel screwdriver adjust in local or through 10-bit DAC in remote mode. (See note).
Threshold monitor point on front panel has 10 : 1 ratio of monitor voltage to actual voltage +/-5%.
Hysteresis, typical 6 mV.

Test Input:

One Lemo-type connector on rear panel, 50 Ohm +/-2%, triggers all enabled channels. Requires NIM-level signal (> -600 mV).

Minimum width:

3 nsec.

Maximum rate:

200 MHz.

Veto Input:

One Lemo-type front panel connector, 50 Ohm +/-2%. Permits simultaneous fast inhibiting of all channels. Requires NIM-level signal (> -600 mV).
Direct-coupled.
Must precede input signal by approximately 3.5 nsec and overlap its leading edge in update mode or overlap complete input signal in burst guard mode.
Minimum duration: 5 nsec.

OUTPUT CHARACTERISTICS

Two bridged outputs per channel.
ECL level (-0.8, -1.7 volt) into 100 Ohm twisted pair. Duration, 4 nsec to 40 nsec. Up to 100 nsec. with restriction (see text above).
Continuously variable via screwdriver control, common to all channels.
Risetimes and falltimes typically 1.5 nsec.
Width stability better than 0.25%/'C maximum.

CAMAC COMMANDS

X:

An X-response is generated when a valid N,A,F command is recognized.

0:

A 0-response is generated only if the requested function can be executed.

Z:

Clears mask register at S2 time.

N - F(l) - A(O):

Reads threshold setting when in local or remote mode.

N - F(l 6) - A(O):

Writes mask register pattern (Wl - W16).

N - F(l 7) - A(O):

Writes threshold setting register; 1 1 bits, 1 0 bits of data providing 1 mV resolution are used to program common threshold received on W1-W10 and 1 bit to set the manual threshold value (front- panel screwdriver control) to the threshold register received on Wll. In this case, the data presented on W1-W10 are ignored. Requires Sl and remote mode switch position.

N - F(25) A(O):

Test function. Only channels not masked off by F(16) are trig- gered by internally generated 3 nsec wide pulse.

N - F(27) A(O):

Remote/local switch test. A 0-response is given when the front- panel switch is in remote mode only.

GENERAL

Double-Pulse Resolution:

Typical, 4 nsec.

Time Slewing:

0.5 nsec for input amplitudes from 2 to 20 times over threshold.

Input-Output Delay:

< 14 nsec.

Test-Output Delay:

< 16 nsec.

Multiple-Pulsing:

None; one and only one output pulse is produced for each input pulse regardless of input pulse amplitude and duration.

Burst Guard:

A rear-panel switch enables the burst guard operation for all channels. The selection of this mode is indicated by a front-panel LED.

Power Requirements:

+24 V at 60 mA
+ 6 V at 400 mA
6 V at 3.4 A
-24 V at 30 mA

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INPUT CHARACTERISTICS
Signal Inputs:	16, Lemo-type front-panel connectors, 50 Ohm +/- 2%. Protected to +/-5 A for 0.5 sec, clamping at +1 and -6 volts. Reflections < 4% for input pulses of 2 nsec risetime. Stability better than 0.2%/'C over 20' C to 60' C operating range offset +/-l mV. Threshold, -15 mV to -1023 mV +/-5% or +/-1.5 mV, whichever is greater, (common to all channels); front panel screwdriver adjust in local or through 10-bit DAC in remote mode. (See note). Threshold monitor point on front panel has 10 : 1 ratio of monitor voltage to actual voltage +/-5%. Hysteresis, typical 6 mV.
Test Input:	One Lemo-type connector on rear panel, 50 Ohm +/-2%, triggers all enabled channels. Requires NIM-level signal (> -600 mV).
Minimum width:	3 nsec.
Maximum rate:	200 MHz.
Veto Input:	One Lemo-type front panel connector, 50 Ohm +/-2%. Permits simultaneous fast inhibiting of all channels. Requires NIM-level signal (> -600 mV). Direct-coupled. Must precede input signal by approximately 3.5 nsec and overlap its leading edge in update mode or overlap complete input signal in burst guard mode. Minimum duration: 5 nsec.
OUTPUT CHARACTERISTICS
Two bridged outputs per channel. ECL level (-0.8, -1.7 volt) into 100 Ohm twisted pair. Duration, 4 nsec to 40 nsec. Up to 100 nsec. with restriction (see text above). Continuously variable via screwdriver control, common to all channels. Risetimes and falltimes typically 1.5 nsec. Width stability better than 0.25%/'C maximum.
CAMAC COMMANDS
X:	An X-response is generated when a valid N,A,F command is recognized.
0:	A 0-response is generated only if the requested function can be executed.
Z:	Clears mask register at S2 time.
N - F(l) - A(O):	Reads threshold setting when in local or remote mode.
N - F(l 6) - A(O):	Writes mask register pattern (Wl - W16).
N - F(l 7) - A(O):	Writes threshold setting register; 1 1 bits, 1 0 bits of data providing 1 mV resolution are used to program common threshold received on W1-W10 and 1 bit to set the manual threshold value (front- panel screwdriver control) to the threshold register received on Wll. In this case, the data presented on W1-W10 are ignored. Requires Sl and remote mode switch position.
N - F(25) A(O):	Test function. Only channels not masked off by F(16) are trig- gered by internally generated 3 nsec wide pulse.
N - F(27) A(O):	Remote/local switch test. A 0-response is given when the front- panel switch is in remote mode only.
GENERAL
Double-Pulse Resolution:	Typical, 4 nsec.
Time Slewing:	0.5 nsec for input amplitudes from 2 to 20 times over threshold.
Input-Output Delay:	< 14 nsec.
Test-Output Delay:	< 16 nsec.
Multiple-Pulsing:	None; one and only one output pulse is produced for each input pulse regardless of input pulse amplitude and duration.
Burst Guard:	A rear-panel switch enables the burst guard operation for all channels. The selection of this mode is indicated by a front-panel LED.
Power Requirements:	+24 V at 60 mA + 6 V at 400 mA 6 V at 3.4 A -24 V at 30 mA