Stanford Research Systems DS335, User Manual

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2-10 Function Setting
DS335 Synthesized Function Generator
function, an error message will be displayed and the frequency will be set to
the maximum allowed for that function.
Ramps Ramp functions usually ramp up in voltage, downward ramps may be set
entering a negative amplitude (see AMPLITUDE section).
FREQUENCY To display the DS335's output frequency press the [FREQ]. The frequency
units can be Hz, kHz, or MHz, and are indicated by the LEDs on the right of
the display. The DS335 has 1
µ
Hz frequency resolution at all frequencies,
for all functions. The maximum frequency depends on the function selected
as shown below.
Function Frequency Range
Sine
1
µ
Hz
→
3.100000000000 MHz
Square
1
µ
Hz
→
3.100000000000 MHz
Triangle
1
µ
Hz
→
10,000.000000 Hz
Ramp
1
µ
Hz
→
10,000.000000 Hz
Noise 3.5 MHz White Noise (fixed)
Frequency is usually displayed by the DS335 with the highest resolution
possible. However, if the frequency is below 100 Hz, the DS335 will display
the frequency with 1
µ
Hz resolution. At frequencies greater than 1 MHz the
digits below 0.1 Hz cannot be displayed, but the frequency still has 1
µ
Hz
resolution and may be set via the computer interfaces.
If the function is set to NOISE the character of the noise is fixed with a band
limit of 3.5 MHz. The frequency is not adjustable and the FREQ display will
read "noise" instead of a numerical value.
Setting the Frequency To set the frequency of any function simply type a new value on the keypad
and complete the entry with the appropriate units (Hz, kHz, or MHz). Also,
the UP and DOWN arrow keys may be used to increment or decrement the
frequency by adding or subtracting one from the flashing digit.
AMPLITUDE Press [AMPL] to display the amplitude of the output function. The amplitude
may be set and displayed in units of V
pp
and V
rms
. The current units are
indicated by the LEDs at the right of the display. The amplitude range is
limited by the DC offset setting since |V
ac peak
| + |V
dc
|
≤
5 V (into 50
Ω
). If
the DC offset is zero the amplitude range for each of the functions is shown
below:
Note: The rms value for NOISE is based on the total power in the output
bandwidth (about 3.5 MHz) at a given peak to peak setting.
Vpp Vrms
Function Max. Min. Max. Min.
Sine 10V 50 mV 3.54V 0.02Vrms
Square 10V 50 mV 5.00V 0.03Vrms
Triangle 10V 50 mV 2.89V 0.01Vrms
Ramp 10V 50 mV 2.89V 0.01Vrms
Noise 10V 50 mV 1.62V 0.01Vrms
50
Ω Ω Ω Ω
Load Impedance