Auxiliary Electrometer Specifications
97
Appendix E:
Auxiliary Electrometer Specifications
Unless otherwise mentioned, all specifications apply at 22
C, zero common-mode voltage versus Ground FA,
input voltages with
Z
out
< 10 Ω, and all channel inputs (other than those of the channel under test) at zero volts
versus Ground FA. All measurements are made with the Aux Channel A/D with normal Framework calibration.
DC Voltage Measurement
Offset Voltage
< 500 µV
20
C to 25
C
at all gain ranges
Temp Drift
< 10 µV/
C
from 0
C to 45
C
Ranges
50 mV,
500 mV,
5V
Full Scale
Differential Input Voltage
Resolution
1.666 µV, 16.66 µV,
166.6 µV
per bit
on all ranges
Gain Error
< 0.3%
on all ranges
Offset Range
5.12 V
offset of differential signal
Offset Resolution
166.6 µV/bit
Input Current
< 10 pA
zero volts input
measure by voltage
Input Impedance
Common Mode
>30 G
in parallel with
<100 pF
−36 V < Vcm < 36 V
versus floating ground
Differential
>100 G
in parallel with
<40 pF
−5 V < Vdiff < 5 V
measured between the
two inputs
Common Mode Rejection
CMR Range
−36 V < Vin < 36 V
versus floating ground
CMRR
> 94 dB
> 86 dB
at 3 Hz
at 100 kHz
Crosstalk
Low Frequency
< −90 dB
DC to 10 kHz
High Frequency
< −80 dB
10 kHz to 100 kHz
Other AC Specifications
Bandwidth
>2 MHz
-3 dB
Phase Shift
<1
<1
DC to 20 kHz
20 kHz to 100 kHz
Noise
<4 µV
pp
<10 nV/Hz
1/2
0.1 Hz to 10 Hz
at 1 kHz
