(5) Divide by the number of channels to determine the maximum scan rate. Assumes an Ethernet or
USB high-high connection. Other USB connections might not be able to maintain 50 ksamples/s. See
Section 3.2 for more information.
(6) When scanning more than 1 channel in a stream, this is the time between each sample within a
scan.
Parameter
Conditions
Min
Typical
Max
Units
Analog Outputs
Nominal Output Range (1)
No Load
0.02
4.86
volts
@ ±2.5 mA
0.225
4.775
volts
Resolution
12
bits
Absolute Accuracy (2)
5% to 95% FS
±0.1
% FS
Integral Linearity Error
±2
counts
Differential Linearity Error
±1
counts
Error Due To Loading
@ 100 µA
0.1
%
@ 1 mA
1
%
Source Impedance
50
Ω
Short Circuit Current
Max to GND
100
mA
Slew Rate
0.8
V/µs
Digital I/O
Low Level Input Voltage
-0.3
1
volts
High Level Input Voltage
2.3
Vs + 0.3
volts
Maximum Input Voltage (3)
FIO
-10
10
volts
EIO/CIO/MIO
-6
6
volts
Input Leakage Current
10
µA
Output Low Voltage (4)
No Load
0
volts
--- FIO
Sinking 1 mA
0.55
volts
--- EIO/CIO/MIO
Sinking 1 mA
0.18
volts
--- EIO/CIO/MIO
Sinking 5 mA
0.9
volts
Output High Voltage (4)
No Load
3.3
volts
--- FIO
Sourcing 1 mA
2.75
volts
--- EIO/CIO/MIO
Sourcing 1 mA
3.12
volts
--- EIO/CIO/MIO
Sourcing 5 mA
2.4
volts
Short Circuit Current (4)
FIO
6
mA
EIO/CIO/MIO
18
mA
Output Impedance(4)
FIO
550
Ω
EIO/CIO/MIO
180
Ω
Counter Input Frequency (5)
3
MHz
Input Timer Total Edge Rate (6)
No Stream
100000
edges/s
While Streaming
25000
edges/s
(1) Maximum and minimum analog output voltage is limited by the supply voltages (Vs and GND). The
specifications assume Vs is 5.0 volts. Also, the ability of the DAC output buffer to drive voltages close
to the power rails, decreases with increasing output current, but in most applications the output is not
sinking/sourcing much current as the output voltage approaches GND.
(2) Analog output accuracy is specified from 5% to 95% of full-scale output.
(3) Maximum voltage to avoid damage to the device. Protection works whether the device is powered
or not, but continuous voltages over 5.8 volts or less than -0.3 volts are not recommened when the
UE9 is unpowered, as the voltage will attempt to supply operating power to the UE9 possibly causing
poor start-up behavior.
(4) These specifications provide the answer to the common question: "How much current can the
digital I/O sink or source?". For instance, if EIO0 configured as output-high and shorted to ground, the
current sourced by EIO0 into ground will be about 18 mA (3.3/180). If connected to a load that draws 5
mA, EIO0 can provide that current but the voltage will droop to about 2.4 volts instead of the nominal
3.3 volts. If connected to a 180 ohm load to ground, the resulting voltage and current will be about 1.65
volts @ 9 mA.
(5) Hardware counters. 0 to 3.3 volt square wave. Default power level is "High".
(6) To avoid missing edges, keep the total number of applicable edges on all applicable timers below
this limit. See Section 2.10 for more information.
Appendix B - Noise and Resolution Tables
The following tables provide typical noise levels of the UE9 under ideal conditions. The resulting voltage resolution is then
calculated based on the noise levels. Also see the LJTick-InAmp datasheet which provides similar tables with the instrumentation
amplifier installed.
Measurements were taken with AIN0 connected to GND with a short jumper wire, or from internal ground channel #15. Similar
results were obtained with other quiet signals such as a 2.048 reference (REF191 from Analog Devices), a 1.5 volt D-cell battery,
and a temperature sensor (LM34CAZ from National Semiconductor).
All “counts” data are aligned as 24-bit values. To equate to counts at a particular resolution (Res) use the formula counts/(2^(24-
Res)). For instance, with the UE9 set to 12-bit resolution and the 0-5 volt range, there are 8192 counts of noise when looking at 24-
bit values. To equate this to 12-bit data, we take 8192/(2^12) which equals 2 counts of noise when looking at 12-bit values.
Noise-free data is determined by taking 128 readings and subtracting the minimum value from the maximum value.
RMS and Effective data are determined from the standard deviation of 128 readings. In other words, the RMS data represents
most readings, whereas noise-free data represents all readings.
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Содержание UE9
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