PRODUCT SPECIFICATION
RM3183
7
Applications Information
The standard connections for the RM3183 are shown in
Figure 1. Dual supplies from
±
12 to
±
15 VDC are recom-
mended for the
±
V
S
supplies. Decoupling of all supplies
should be done near the IC to avoid propagation of noise
spikes due to switching transients. The ground connections
should be sturdy and isolated from large switching currents
to provide as quiet a ground reference as possible.
The noise filter capacitors are optional and are added to
provide extra noise immunity by limiting the noise band-
width of the input signal before it reaches the comparator.
Two capacitors are required for each channel and they must
all be the same value. The suggested capacitor value for a
100 KHz operation is 39 pF, which will give a noise band-
width of approximately 800 KHz. For lower data rates, larger
values of capacitance may be used to yield better noise
performance. To get optimum performance, the following
equation should be used to calculate capacitor value for a
specific data rate:
The RM3183 can be used with Raytheon’s RM3182 Line
Driver to provide a complete analog ARINC 429 interface.
A simple application which can be used for systems requir-
ing a repeater-type circuit for long transmissions or test
interfaces is given in Figure 2. More RM3182 drivers may be
added to test multiple ARINC channels, as shown.
An all digital IC is available which forms a complete
receiver system when combined with the RM3183. The
Thomson EF4442 is a four channel ARINC 429 receiver IC
which contains all the digital circuitry required to interface
with an 8-bit processor. Each channel consists of a 32-bit
register, an 8-bit status word comparator, and a 24-bit latch.
A multiplexer and 8-bit data bus buffer form the interface to
the system microprocessor. Figure 3 shows a typical ARINC
application having both transmit and receive functions using
four ICs: the EF4442, the RM3182 driver and two RM3183
dual receivers.
C
3.95
10
6
–
×
F
O
=
F
O
Data Rate (bits/sec)
=