Measurement Computing USB-1208HS, Руководство пользователя

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USB-1208HS User's Guide Specifications
18
External trigger
Table 6. External trigger specifications
Parameter Specification
Trigger source TRIG input
Trigger mode Software-selectable for edge or level sensitive, rising or falling edge, high or low level.
Power on default is edge sensitive, rising edge.
Trigger latency 1 µs + 1 clock cycle max
Trigger pulse width 100 ns min
Input type Schmitt trigger, 33
Ω series resistor and 47 kΩ pull
-down to ground
Schmitt trigger hysteresis 0.4 V to 1.2 V
Input high voltage 2.2 V min
5.5 V absolute max
Input low voltage 1.5 V max
–0.5 V absolute min
0 V recommended min
External clock input/output
Table 7. External clock I/O specifications
Parameter Specification
Terminal names AICKI, AICKO
Terminal types AICKI: Input, active on rising edge
AICKO: Output, power on default is 0 V, active on rising edge
Terminal descriptions AICKI: Receives sampling clock from external source
AICKO: Outputs the internal sampling clock (A/D clock) or pulse generated from AICKI
when in external clock mode
Input clock rate 1 MHz max
Clock pulse width AICKI: 400 ns min
AICKO: 400 ns min
Input type Schmitt trigger, 33
Ω series resistor, 47 kΩ pull
-down to ground
Schmitt trigger hysteresis 0.4 V to 1.2 V
Input high voltage 2.2 V min
5.5 V absolute max
Input low voltage 1.5 V max
–0.5 V absolute min
0 V recommended min
Output high voltage 4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –24 mA)
Output low voltage 0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 24 mA)
Output current ±24 mA max per terminal (refer to Power section for additional information)