Measurement Computing USB-1208HS-4AO - Manual (Page 19)

USB-1208HS-4AO User's Guide Specifications
19
External trigger
Table 7. 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 8. External clock I/O specifications
Parameter Specification
Terminal names AICKI, AICKO, AOCKI, AOCKO
Terminal types AxCKI: Input, active on rising edge
AxCKO: Output, power on default is 0 V, active on rising edge
Terminal descriptions AxCKI: Receives sampling clock from external source
AxCKO: Outputs the internal sampling clock (D/A or A/D clock) or pulse generated from
AxCKI when in external clock mode
Input clock rate 1 MHz max
Clock pulse width AxCKI: 400 ns min
AxCKO: 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)