National Instruments AT-MIO-64F-5, User Manual

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Chapter 2 Configuration and Installation
© National Instruments Corporation 2-35 AT-MIO-64F-5 User Manual
Signal
Source
33
DIG GND
Counter
OUT
SOURCE
GATE
+5 V
4.7 k
W
MIO Subconnector
AT-MIO-64F-5 Board
Gate
Source
Figure 2-18. Frequency Measurement Application
Two or more counters can be concatenated by tying the OUT signal from one counter to the
SOURCE signal of another counter. The counters can then be treated as one 32-bit or 48-bit
counter for most counting applications.
The signals for Counters 1, 2, and 5, and the FOUT output signal are directly tied from the
Am9513A input and output pins to the I/O connector. In addition, the GATE, SOURCE, and
OUT1 pins are pulled up to +5 V through a 4.7 k
W
resistor. The input and output ratings and
timing specifications for the Am9513A signals are given as follows:
Absolute maximum voltage input rating -0.5 V to +7.0 V with respect to DIG GND
Am9513A digital input specifications (referenced to DIG GND):
V
IH
input logic high voltage 2.2 V minimum
V
IL
input logic low voltage 0.8 V maximum
Input load current ±10 µA maximum
Am9513A digital output specifications (referenced to DIG GND):
V
OH
output logic high voltage 2.4 V minimum
V
OL
output logic low voltage 0.4 V maximum
I
OH
output source current, at V
OH
200 µA maximum
I
OL
output sink current, at V
OL
3.2 mA maximum