Measurement Computing USB-205 - Manual (Page 14)

14
Chapter 4
Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.
Analog input
Table 1. General analog input specifications
Parameter Condition Specification
A/D converter type Successive approximation
ADC resolution 12 bits
Number of channels 8 single-ended
Input voltage range ±10 V
Absolute maximum input
voltage CHx relative to AGND  ±25 V max (power on)
 ±25 V max (power off)
Input impedance  1 MΩ (power on)

1 MΩ (power off)
Input bias current 10 V input –12 µA
0 V input 2 µA
–10 V input 12 µA
Input bandwidth Small signal (–3 dB) 1.0 MHz
Maximum working voltage Input range relative to
AGND ±10.1 V max
Crosstalk Adjacent channels, DC to
10 kHz –75 dB
Input coupling DC
Sampling rate Internal pacer 0.016 S/s to 500 kS/s, software-selectable
External pacer 500 kS/s max
Sample clock source  Internal A/D clock
 Pacer input terminal AICKI
Channel queue Up to eight unique, ascending channels
Throughput Software paced 33 S to 4,000 S/s typ, system dependent
Hardware paced 500 kS/s max, system dependent
Warm-up time 15 minutes min
Accuracy
Analog input DC voltage measurement accuracy
Table 2. DC Accuracy components and specifications. All values are (±)
Range
Gain error
(% of reading)
Offset error
(mV)
Absolute accuracy
at Full Scale
(mV)
Gain temperature
coefficient
(% reading/°C)
Offset
temperature
coefficient
(mV/°C)
±10V 0.098 11 20.8 0.016 0.87