Appendix A
Specifications
PCI-DIO-96/PXI-6508/PCI-6503 User Manual
A-2
ni.com
Output Signals
Pin 49 (at +5 V) ......................................1.0 A max
Output current.........................................2.5 mA typ
Caution
Drawing more than the typical 2.5 mA current (<2 k
Ω
load at 5 V output) can
cause serious damage to the device 82C55 PPI. The 82C55 PPI is intended for use as a
logic device, and should not be used as current driver for LEDs, SSRs, mechanical relays,
and so on, which can have low impedance loads and/or require high current drive. If you
require higher current drive, consider using the NI PCI/PXI-6509 5V/TTL 96-line
Industrial DIO board with 24 mA current driver, using an NI PCI/PXI-651
x
high-current
drive Industrial DIO board, or using external circuitry such as Darlington Arrays to
increase the current drive of digital output lines. For more information about the
breakdown levels of your device and for a link to the 82C55 data sheets, refer to
ni.com/info
and enter the info code
82c55
.
Level
Min
Max
Input logic high voltage
2.2 V
5.3 V
Input logic low voltage
−
0.3 V
0.8 V
Input high current
(V
in
= 5 V, resistors set to pull-up
†
)
—
10
μ
A
‡
Input high current
(V
in
= 5 V, resistors set to pull-down
†
)
—
75
μ
A
Input logic low current
(V
in
= 0 V, resistors set to pull-up
†
)
—
−
75
μ
A
Input logic low current
(V
in
= 0 V, resistors set to pull-down
†
)
—
−
10
μ
A
‡
†
The PCI-DIO-96 bias resistors are always set to pull-up. On the PXI-6508 and PCI-6503,
use jumper W1 to select pull-up or pull-down.
‡
Exception: Lines PC3 and PC0 are 20
μ
A.
Level
Min
Max
Output logic high voltage (I
ol
= –2.5 mA)
3.0 V
5.0 V
Output logic high voltage (I
oh
= –4 mA)
2.7 V
5.0 V
Output logic low voltage (I
ol
= 2.5 mA)
0 V
0.4 V
Output logic low voltage (I
ol
= 4 mA)
0 V
0.5 V