TFG2900A Series Function/Arbitrary Waveform Generator Users’ Guide
Suin Instruments Co., Ltd
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parameter setting. For Square, duty cycle can be set, while for Pulse, not only duty cycle, but also
pulse width and edge time could be set.
Duty cycle: it means ratio of time that Square or Pulse’s high level occupied to period. If you
select Square or Pulse, you can set their duty cycle by pressing
〖
Duty
〗
in continuous mode menu.
When their frequency is changing, their duty cycle remains unchanged. But when the frequency is
high, duty cycle setting will be limited by smallest pulse width, which should conform to the
following rules:
3.2ns≤ (duty cycle*period) ≤ (period-3.2ns)
Pulse width: it means the hold time starting from the middle of rising edge to middle of the falling
edge. If pulse is selected, you can set its pulse width by pressing
〖
Width
〗
in continuous mode.
Pulse width setting is limited not only by pulse frequency, but also by smallest pulse width, which
should conform to the following rules:
3.2ns ≤ pulse width ≤ (period-3.2ns)
When pulse wave’s frequency is changing not exceeding the above rule, pulse width will remain
unchanged. But if it exceeds, instrument will modify pulse width value automatically to make it
suitable for pulse frequency.
Edge time: it means the hold time pulse wave’s rising edge rises from 10% amplitude to 90%, or
pulse wave’s falling edge falls down from 90% to 10% amplitude. If Pulse is selected, you can set
edge time of rising edge and falling edge by pressing
〖
Rising
〗
or
〖
Falling
〗
in continuous mode.
Edge time will be limited by pulse width and duty cycle, which should conform to the following
rule:
Rising edge time/0.8 + high level time≥5ns
Falling edge time/0.8 + low level time≥5ns
If pulse width and duty cycle don’t exceed the above formula specified, the edge time will remain
unchanged. If they exceed the rules above, instrument will modify edge time automatically to
make it suitable for pulse width and duty cycle.
3.2.3 Ramp
: Ramp can set symmetry. Ramp’s symmetry means the ratio of rising time to period.
When Ramp’s frequency changing, its symmetry remains unchanged. When symmetry is 100%, it
is Rising Ramp. When symmetry is 0%, it is Fall Ramp. When symmetry is 50%, it is Triangle.
