CIRCUIT TECHNOLOGYwww.aeroflex.com/act1.htm
eroflex Circuit Technology – Data Bus Modules For The Future © SCD4489 REV A 1/29/98
General Description
The Aeroflex Circuit
Technology ACT 4489 is a next
generation monolithic transceiver
design which provides full
compliance to MIL-STD-1553A/B
and 1760 requirements in a small
package with low power
consumption.
The ACT4489 series performs
the front-end analog function of
inputting and outputting data
through a transformer to the
MIL-STD-1553 data bus.
Design of this transceiver 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. Efficient
transmitter electrical and thermal
design provides low internal power
dissipation and heat rise at high as
well as low duty cycles.
Transmitter:
The Transmitter section accepts
bi-phase TTL data at the input and
when coupled to the data bus with a
1:1 ratio transformer, isolated on
the data bus side with two 52.5
Ohm fault isolation resistors, and
loaded by two 70 Ohm
terminations, the data bus signal is
typically 7 Volts P-P at point A (See
Figure5). 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
Block Diagram (Without Transformer)
ACTIVE OUTPUT
STAGE
COMP.
COMP.REFERENCE
ACTIVE
FILTER
INPUT
AMPLIFIER
DRIVER
TX DATA IN
TX DATA IN
TX INHIBIT IN
RX DATA IN
RX DATA IN
RX STROBE IN
TX DATA OUT
TX DATA OUT
RX DATA OUT
RX DATA OUT
FILTER
-12V (VEE)
GND3
+5V (VL)
GND1
+12V (VCC)
GND2
CASE
Features
• +5 / ±12 Volt Supply Operation
• Low Power Dissipation
• Small Size & Light Weight
• Outstanding MIL-STD-1553 performance
• Radiation Hard Dielectric Isolation Monolithic
Construction for Severe Environments
• Superior High Frequency Line Transient and
Input Ripple Rejection
• Input and Output TTL Compatible Design
• Processed and Screened to MIL-STD-883 Specs
• MIL-PRF-38534 Compliant Devices Available
ACT 4489 SINGLE TRANSCEIVER
FOR MIL-STD-1553/1760