Measurement Computing PCIe-DIO24 - Manual (Page 12)

12
Chapter 4
Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Digital input/output
Table 1. Digital I/O specifications
Parameter Specification
Digital type 82C55 Emulation
Configuration 2 banks of 8, 2 banks of 4, programmable by bank as input or output
Output
Ports A and B: 74HC245A
Port C: 74HC126
Input
Ports A and B: 74HC245A
Port C: 74HC125
Number of channels 24 I/O
Switch state Board silk screen reference: S1 – Default +5V
Output high
3.3 V
2.8 volts min @ -2.5 mA
Output low 0.3 volts max @ 2.5 mA
Input high 2.6 volts min, 3.6 volts absolute max
Input low 1.3 volts max, -0.5 volts absolute min
Output high
5 V
4.5 volts min @ -2.5 mA
Output low 0.3 volts max @ 2.5 mA
Input high 2.6 volts min, 5.5 volts absolute max
Input low 1.3 volts max, -0.5 volts absolute min
Power-up /reset state Input mode (10 kΩ impedance from pull-up or pull-down)
Pull-up/pull-down resistors
EEPROM stored; software programmable driven by 74ACT244 through 10 kΩ bussed
resistor networks (shipped in the pull-up state)
Interrupt enable
External (IRQ ENABLE, active low, disabled by default through internal resistor to TTL
high) and programmable through PCI9030; 0 = disabled, 1 = enabled (default)
Interrupt sources
External source (IRQ INPUT), polarity programmable through PCI9030;
1 = active high, 0 = active low (default)
Power consumption
Table 2. Power consumption specifications
Parameter Specification
+3.3 V operating 515 mA typ
+3.3 V with 5 V I/O 520 mA typ
+V
DIO
User output 125 mA max @ +5V; 375 mA max @ +3.3 V
Fuses
+V
DIO
User output and +12 V:
Littelfuse 0.375A NANO 2® Slo-Blo ® Subminiature Surface Mount Fuse; art number
0452.375