18
Trigger Modes
The LDP-QCW supports four different trigger modes as explained below. In order to change
the trigger mode, the driver must be disabled (enable = 0) and the TRG_MODE and
TRG_EDGE bits in the LSTAT register must be set accordingly.
Internal (trgmode = 0)
The pulse generation is performed by an internal pulse generator. The pulse width and
repetition rate are user configurable via the serial interface. In addition, the number of pulses
that will be generated when the driver is enabled can be set from a single pulse to a
continuous pulse generation while the driver is enabled.
The following diagram shows an example of generated pulses. The lower graph shows the
internal pulse generator, the upper two graphs the trigger pulses generated out of it.
Symbol
Meaning
T
1
Enabling of the output.
T
1
-T
2
Delay between output enable and the first generated pulse depends on
the configured repetition rate. It nearly equals the pulse pause time.
T
2
-T
3
Pulse rise time. It depends on the load inductance.
T
4
-T
5
Pulse fall time. It depends on the load inductance.
T
6
Disabling of the output.
T
7
Re-enabling of the output.
