Measurement Computing USB-2020 - Manual (Page 21)

USB-2020 User's Guide Specifications
External trigger
Table 6. External trigger specifications
Parameter Condition Specification
Trigger source Digital TRIG IN (BNC connector and 40-pin connector)
Analog CH0 or CH1
Trigger mode Digital Rising or falling edge, high or low level
Analog Trigger above or below software-selectable level, rising or
falling edge with software-selectable hysteresis
A/D gate source Digital TRIG IN (BNC connector and 40-pin connector)
Analog CH0 or CH1
A/D gate modes Digital High or low level
Analog Software-selectable high or low level, in or out of software-
selectable window
Trigger latency 50 ns max
Trigger pulse width 25 ns min
Input type 49.9 Ω series resistor
Input high voltage 2.0 V min
Input low voltage 0.8 V max
External clock input/output
Table 7. External clock I/O specifications
Parameter Specification
Terminal name CLK IO (BNC connector)
Terminal type ADC clock input/output, software-selectable for input or output (default is input)
Terminal description

When configured for input, receives sampling clock from external source

When configured for output, outputs the internal sampling clock
Clock rate 1 kHz to 20 MHz max
Stability ±50 ppm
Input impedance 1 MΩ
Input threshold High: 2.0 V min
Low: 0.8 V max
Maximum rate 20 MHz
Input range 0 V to 5.5 V
Clock pulse width 25 ns min
Input type 49.9 Ω series resistor
Input high voltage 2.0 V min
Input low voltage 0.8 V max
Output high voltage 2.4 V min
Output low voltage 0.4 V max
Output current 24 mA max
Memory
Table 8. Memory specifications
Parameter Specification
Data FIFO 64 MS using BURSTIO, 4 kS not using BURSTIO
Non-volatile memory 32 KB (30 KB firmware storage, 2 KB calibration/user data)
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