Standard Products
ACT4404N Single Transceiver
for MACAIR (A3818, A4905, A5232, A5690), MIL-STD-1553
& SAE-AS15531
www.aeroflex.com/Avionics
March 4, 2005
FEATURES
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ACT4404N transceiver meets MIL-STD-1553A & B, Macair A3818, A4905, A5232 and A5690 specs
Bipolar supply ±15V to ±12V, logic supply +5V
Monolithic construction
Direct replacement for CT3232M
Voltage source output for higher bus drive power
Variable receiver threshold capability
Designed for commercial, industrial and aerospace applications
MIL-PRF-38534 compliant devices available
Aeroflex-Plainview is a Class H & K MIL-PRF-38534 manufacturer
GENERAL DESCRIPTION
The Aeroflex-Plainview transceiver model ACT4404N is a new generation monolithic transceiver which provide full compliance
with Macair and MIL-STD-1553 data bus requirements.
The model ACT4404N performs the front-end analog function of inputting and outputting data through a transformer to a
MIL-STD-1553 or Macair data bus. The ACT4404N can be considered a "Universal" Transceiver in that it is compatible with
MIL-STD-1553A/B, Macair (A-3818, A-4905, A-5232 and A-5690).
Design of these transceivers reflects particular attention to active filter performance. This results in low bit and word error rate
with superior waveform purity and minimal zero crossover distortion. The ACT4404N active filter design has additional high
frequency roll-off to provide the required Macair low harmonic distortion waveform without increasing the pulse delay
characteristics significantly.
Efficient transmitter electrical and thermal design provides low internal power dissipation and heat rise at high and well as low
duty cycles. An optional receiver input threshold adjustment can be accomplished by the use of the ''External Threshold"
terminals.
TRANSMITTER
The Transmitter section accepts bi-phase TTL data at the input and when coupled to the data bus with a 1:1 transformer the data
bus signal produced is 7.0 Volts typical P-P at point A-A’ (See Figure 3 or 4). When both DATA and DATA inputs are held low or
high, the transmitter output becomes a high impedance and is “removed” from the line. In addition, an overriding "INHIBIT''
input provides for the removal of the transmitter output from the line. A logic '' 1'' applied to the '' INHIBIT'' takes priority over
the condition of the data inputs and disables the transmitter (See Transmitter Logic Waveforms - Figure 1).
The transmitter utilizes an active filter to suppress harmonics above 1 MHz to meet Macair specifications A-3818, A-4905,
A-5232 and A-5690. The transmitter may be safely operated for an indefinite period at 100% duty cycle into a data bus short
circuit.
The transceiver utilizes an active filter to suppress harmonics above 1MHz. The Transmitter may be safely operated at 100%
duty cycle for an indefinite period into a short circuited 1553 bus.
RECEIVER
The Receiver section accepts bi-phase differential data at the input and produces two TTL signals at the output. The outputs are
DATA and DATA, and represent positive and negative excursions of the input beyond a pre-determined threshold (See Receiver
Logic Waveforms - Figure 2).
The internal threshold is nominally set to detect data bus signals exceeding 1.05 Vp-p and reject signals less than 0.6 Vp-p when
used with a 1:1 turns ratio transformer (See Figure 3 or 4 for transformer data and typical connection). This threshold setting can
be held by grounding the appropriate pins or modified with the use of external resistors.
A low level at the ''STROBE'' input inhibits the DATA and DATA outputs. If unused, a 2K Ohm pull-up to +5V
DC
is
recommended.
SCD4404N Rev C
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
