TFG2900A Series Function/Arbitrary Waveform Generator Users’ Guide
Suin Instruments Co., Ltd
29
polarity’s waveform.
3.2.11 Sync output
: Sync signal’s frequency is equal to output signal’s. But when the frequency
exceeds 66.66667MHz, sync signal’s frequency will be one sixth of output signal’s.
3.2.12 External load
: In continuous mode menu, press
〖
OutputMenu
〗
, and then press
〖
Load
〗
,
external load menu will display and you can set it.
The fixed output impedance is 50Ω, and external load’s actual voltage value is the partial voltage
between load impedance and 50Ω. When external load is set to high impedance, the higher it is,
the bigger the actual voltage in external load is, and the smaller the real voltage and the displaying
value are. When external load is greater than 10kΩ, error will be lower than 0.5%. If external load
is smaller, the actual voltage will not match with displaying value in load.
When external load is smaller, in order to make the actual voltage match with displaying value,
the setting for external load is required.
Press
〖
50Ω
〗
, you can directly set the external load to 50Ω.
Press
〖
High-Z
〗
, you can directly set the external load to high impedance.
Press
〖
Res
〗
, you can set the actual value of external load.
The amplitude and offset’s displaying value will change accordingly when setting for external
load changing. But the actual output doesn’t change. If you connect an external load whose actual
value is equal to the setting value, then the actual voltage of load will match with the current
displaying value.
The default status of external load is high impedance (High-Z) when power on the instrument.
Please be noted, most of the external load are not pure resistive. Perceptual impedance and
capacitive impedance will change with the frequency. This will not be ignored when frequency is
higher. If the exact external load’s impedance is not sure, you can make it to match with the real
displaying value through changing the external load’s setting value step by step. At this time,
external load’s setting value is equal to external load’s actual impedance.
3.2.13 Output protection
: Instrument’s output impedance is 50Ω and it won’t be damaged by
short circuit in short time at output port. The instrument has over-voltage protection, when higher
voltage is connected to the output port, protection circuit will disable the output immediately, and
display the alarm information with sounds. Users should check load port. After confirming the