National Instruments NI USB-9201, User Manual And Specifications, Page: 14 / 21

NI USB-9201/9221 User Guide and Specifications 14 ni.com
NI USB-9201/9221 Circuitry
The NI USB-9201/9221 channels are isolated, and the device protects each
channel from overvoltages. The input signals are scanned, buffered,
conditioned, and then sampled by a single 12-bit ADC. For more
information about overvoltage protection, refer to the
Specifications
section.
Figure 11. Input Circuitry for One Channel
Specifications
The following specifications are typical for the range 0 to 60 °C
unless otherwise noted. All voltages are relative to COM unless otherwise
noted.
Input Characteristics
Number of channels................................8
ADC resolution.......................................12 bits
Type of ADC ..........................................Successive approximation
register (SAR)
Sample rate (aggregate)
1
NI USB-9201
Single channel ..........................800 kS/s max
Scanning ...................................500 kS/s
NI USB-9221...................................800 kS/s max
1
Full performance requires the use of a USB 2.0 Hi-Speed host controller and USB 2.0 hubs.
USB-9201/9221
Mux
COM
AI 7
AI 0
Isolated
ADC
Overvoltage
Protection
Buffer