![background image](http://html2.mh-extra.com/html/keithley/6514/6514_instruction-manual_4064199156.webp)
11-10
Digital I/O, Analog Outputs, and External Feedback
Since the preamp output signal is not corrected during calibration, gain error of up to 15%
may appear at this output, depending on function and range selection. For all volts ranges,
preamp output accuracy is typically 10ppm.
WARNING
High voltage may be present between the preamp output and common ter-
minals depending on the input signal (see Table 11-3).
CAUTION
Connecting preamp output, common, or 2V analog output to earth while
floating the input may damage the instrument
.
Note that the preamp out output resistance is 1
Ω
. The output resistance appears between input
low and analog output low to keep the resistor out of the loop when using external feedback ele-
ments. To keep loading errors under 0.1%, the device connected to the preamp output should
have a minimum input impedance of 100k.
CAUTION
To prevent damage to Model 6514, do not connect a device to preamp out
that will draw more than ±100µA. For example, at 200V, the impedance
connected to preamp out must be at least 2M
Ω
(200V/100µA = 2M
Ω
).
Table 11-3
Full-range preamp out values
Function
Range
Full-range
value
Volts
2V
2V
20V
20V
200V
200V
Amps
2nA, 2µA, 2mA
2V
20pA, 20nA, 20µA, 20mA
20V
200pA, 200nA, 200µA
200V
Ohms
2k
Ω
, 2M
Ω
, 2G
Ω
2V
20k
Ω
, 20M
Ω
, 20G
Ω
20V
200k
Ω
, 200M
Ω
, 200G
Ω
200V
Coulombs
20nC, 2µC
20V
200nC, 20µC
200V
Summary of Contents for 6514
Page 203: ...14 CommonCommands...
Page 207: ...15 SCPISignalOriented MeasurementCommands...
Page 235: ...18 PerformanceVerification...
Page 254: ...19 Calibration...
Page 274: ...20 RoutineMaintenance...
Page 278: ...A Specifications...
Page 282: ...B StatusandErrorMessages...
Page 288: ...C GeneralMeasurement Considerations...
Page 294: ...D DDCEmulationCommands...
Page 299: ...E ExamplePrograms...
Page 306: ...F IEEE 488BusOverview...
Page 320: ...G IEEE 488andSCPI ConformanceInformation...
Page 324: ...H CalibrationOptions...