Operator`s manual

Signametrics 38

ll three source functions use the V,Ω+, and the V,Ω- terminals of the SM2044.

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4.13.1 DC Voltage Source

The SM2044 has a fully isolated bipolar DC voltage source. Two modes of operation are available: fast settling or

closed loop. In the ClosedLoop mode the DMM monitors the voltage source output, and updates it using the

composite 16 bit DAC, at a rate proportional to the set measurement rate. The ClosedLoop mode offers the best

accuracy and resolution. A 10 rps or lower measurement rate is recommended for the ClosedLoop mode. In the f

settling mode, no adjustments are made and the 12-bit DAC is used. Up to ±10.0 V can be sourced, with 10 mA

maximum drive. The output source resistance of the DCV source is approximately 220 Ω. See Figure 4-13 for

connection.

Figure 4-13. Sourcing DC voltage. Monitoring of the output in closed loop operation.

4.13.2 AC Voltage Source

The AC voltage source is fully isolated. It has two modes of operation: fast settling or closed loop. In the

ClosedLoop mode, the source voltage is monitored, and corrections are made to the composite 16-bit DAC at a rate

proportional to the set measurement rate. A 10 rps or lower reading rate is recommended for the ClosedLoop mode.

The ClosedLoop mode offers the best accuracy. In the fast settling mode, the source voltage is monitored and can be

displayed, but no DAC adjustments are made. Both amplitude and frequency can be set. The frequency range is

2 Hz to 75 kHz, and the amplitude is up to 20 V peak-to-peak with 10 mA maximum peak current drive. The output

impedance is approximately 250 Ω.