External Trigger; External Clock Input/Output; Memory - Measurement Computing USB-2020 User Manual

USB-2020 User's Guide

External trigger

Parameter
Trigger source
Trigger mode
A/D gate source
A/D gate modes
Trigger latency
Trigger pulse width
Input type
Input high voltage
Input low voltage

External clock input/output

Parameter
Terminal name
Terminal type
Terminal description
Clock rate
Stability
Input impedance
Input threshold
Maximum rate
Input range
Clock pulse width
Input type
Input high voltage
Input low voltage
Output high voltage
Output low voltage
Output current

Memory

Parameter
Data FIFO
Non-volatile memory
Table 6. External trigger specifications
Condition
Digital
Analog
Digital
Analog
Digital
Analog
Digital
Analog
Table 7. External clock I/O specifications
Specification
CLK IO (BNC connector)
ADC clock input/output, software-selectable for input or output (default is input)
When configured for input, receives sampling clock from external source

When configured for output, outputs the internal sampling clock

1 kHz to 20 MHz max
±50 ppm
1 MΩ
High: 2.0 V min
Low: 0.8 V max
20 MHz
0 V to 5.5 V
25 ns min
49.9 Ω series resistor
2.0 V min
0.8 V max
2.4 V min
0.4 V max
24 mA max
Table 8. Memory specifications
Specification
64 MS using BURSTIO, 4 kS not using BURSTIO
32 KB (30 KB firmware storage, 2 KB calibration/user data)
21
Specification
TRIG IN (BNC connector and 40-pin connector)
CH0 or CH1
Rising or falling edge, high or low level
Trigger above or below software-selectable level, rising or
falling edge with software-selectable hysteresis
TRIG IN (BNC connector and 40-pin connector)
CH0 or CH1
High or low level
Software-selectable high or low level, in or out of software-
selectable window
50 ns max
25 ns min
49.9 Ω series resistor
2.0 V min
0.8 V max
Specifications