LW120 User Manual
AM IN
This input accepts signals that amplitude modulate channel 1, 2, or
both signal. The AM input becomes active only when the AM function
is selected otherwise, it has no effect on the output signal.
TRIG/FSK IN
In general, this input accepts signals that stimulate generation of
output waveforms. The trigger input is inactive when the generator is
in continuous operating mode. When placed in trigger, gated or burst
mode, the trigger input is made active and waits for the right condition
to trigger the instrument. In trigger and burst modes, the trigger input
is edge sensitive, i.e., it senses transitions from high to low or from
low to high to trigger the LW120. The direction of the transition is
programmable. In gated mode, the trigger input is level sensitive, i.e.,
the generator is gated when the logic level is high and idle when the
level is logic low. Trigger level for this input is TTL.
The trigger input is common to both channels. Therefore, if the
LW120 is placed in trigger mode, both channels share the same
mode and the trigger input causes both channels to start generating
waveforms at the same time. Phase relationship between channels is
tightly controlled in trigger mode. You should expect both channels to
start generating waves with exactly the same start phase. Further
control of leading edge offset between channels is also provided.
The same input is used in FSK mode, where the output hops between
two frequencies – carrier and shifted frequencies. The output
generates carrier frequency when the FSK input is false and shifted
frequency when the FSK input is true.
The trigger input is also used as stop and start input when the LW120
is placed in Arm mode.
SCLK OUT
This BNC connector outputs the programmed sample clock
frequency. Output level is ECL, terminated into 50
Ω
to –2V. Note that
correct termination is necessary for this output otherwise you will not
see this signal at all. This output generates sample clock waveforms
continuously, regardless if the LW120 is operating in continuous,
trigger, or gated modes.
The sample clock output is used for multiple-instruments
synchronization. In master mode, connect this output with a BNC to
BNC connector to the adjacent slave instrument. You may also use
this output to synchronize other components in your system to one
master clock.
SCLK IN
This BNC connector accepts ECL level signal, terminated into 50
Ω
to
–2V. The external clock input is available for those applications
Getting Started 1-9