6.3 Trigger output
U5303A User's Manual
67
6.3 Trigger output
A trigger output pulse can be generated for external synchonization.
When the ADC card is ready to be triggered and a valid trigger signal occurs, a trigger output pulse is
generated. This signal is available on the front panel TRG OUT MMCX connector, and may be enabled
or disabled as required.
In idle state, Trigger Out signal is low. When a trigger is accepted a high level pulse occurs.
There are several trigger sources or signals which may be assigned to the trigger out connector (See
table below).
Trigger out sources
Description of signal
TriggerAccepted
A pulse signal is sent directly to the Trigger Out.
TriggerAcceptedResync
A pulse signal resynchronized to a sub-multiple of sample clock is sent to
the Trigger Out.
TriggerCompare
The trigger input condition has been satisfied, but not necessarily
triggered, e.g. the trigger enable was not asserted.
SelfTrigger
Used in averaging mode. See
.
HighLevel
Fixed high level signal for debug purposes.
LowLevel (default)
Fixed low level signal for debug purposes.
Table 6.3
- List of supported trigger out signals.
Trigger output signal behavior
By default, the trigger output is
LowLevel
.
If selecting a trigger output source, e.g.
TriggerAcceptedResync
or
TriggerAccepted
as trigger
output source, when the ADC card is ready to be triggered and a valid trigger signal occurs, a trigger
output pulse is generated.
Pulse duration
When using
TriggerAcceptedResync
, the signal is re-synchronized on a sub-multiple of the
sampling clock depending on SR option (SR0: 32.25 MHz, SR1: 62.5 MHz, SR2: 100 MHz, SR3: 125
MHz, or with External Clock :
external clock frequency / 32
).
The pulse duration is typically 480 ns with SR1 option, 300 ns with SR2 option, or 240 ns with SR3
option. If using an external clock, the pulse duration is typically equal to
960 / external clock
frequency
.
When using
TriggerAccepted
, there is no resynchronization. The pulse duration is typically 960
±20 ns with SR0 option,480 ±16 ns with SR1 option, 300 ±10 ns with SR2 option, or 240 ±10 ns with
SR3 option.
