Standard Products
ACT4435N Transceiver
for H009 Specification
June 18, 2004
FEATURES
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ACT4435N Transceiver meets H009 data bus specifications
Transmitter can be used to drive clock signal line
Operates with ±15 Volts to ±12 Volts power supplies
Direct replacement for CT1641 and CT1816 devices
Voltage source output for higher bus drive power
Plug-in and flat package available
Monolithic construction using linear ASICs
Processed and screened to MIL-STD-883 specs
MIL-PRF-38534 compliant devices available
Aeroflex is a Class H & K MIL-PRF-38534 Manufacturer
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ACT4435NFP / 4435N
GENERAL DESCRIPTION
The Aeroflex Laboratories transceiver model ACT4435N is a new generation monolithic transceiver which provide full compliance with
Macair and MIL-STD-1553 data bus requirements
The model ACT4435N performs the front-end analog function of inputting and outputting data through a transformer to a H009 data bus.
The 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 ACT4435N active filter design has additional high frequency roll-off to
provide the required 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, isolated on the
transceiver side with two 35 Ohm bus terminating resistors, with the bus terminated by a 170 Ohm resistor the data bus signal produced is 20.0
Volts typical P-P at A-A’ (See Figure 5). When both DATA and DATA inputs are held low or high, the transmitter output becomes a low
impedance and signal is “removed” from the line. In addition, an overriding “INHIBIT" input returns the output to a high impedance state. 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 H009 specifications. The transmitter may be safely operated
for an indefinite period at 100% duty cycle into a data bus short circuit.
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 Volts P-P and reject signals less than 0.6 Volts P-P when used
with a 1:1 turns ratio transformer (See Figure 5 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 +5 Volts is recommended.
SCD4435N Rev B
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
