SCD4480-DFI

Standard Products

ACT4480-DFI Dual Transceiver

for H009 Specification

www.aeroflex.com/avionics

February 27, 2013

FEATURES

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Dual transceiver meets McDonnell Douglas H009 data bus specifications

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Operates with ±12V to ±15 and +5V power supplies

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Monolithic construction using linear ASICs

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Packaging

– Low profile ceramic

- 0.60''W x 0.80''L x 0.14''H

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Designed for commercial, industrial and aerospace applications

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Full MIL-PRF-38534 qualification pending

DESCRIPTION

The Aeroflex Plainview transceiver model ACT4480-DFI is a new generation monolithic transceiver which

provides compliance with H009 data bus requirements using three DC power supplies operation. The

dual channel ACT4480-DFI performs the front-end analog function of inputting and outputting data

through a transformer to a H009 data bus.

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 active filter

design provides the required H009 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. The receiver input threshold is set internally.

TRANSMITTER

The Transmitter section accepts complementary TTL data at the input, and when coupled to the data

bus with a 1:1 transformer, isolated on the transceiver side with two 34 Ohm bus terminating resistors, with

Figure 5). When both DATA and DATA inputs are held low or high, the transmitter output remains 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 2).

The transmitter utilizes an active filter to suppress harmonics above 1MHz 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 3).

1:1 turns ratio transformer (See Figure 5 for transformer data and typical connection).

A low level at the Strobe input inhibits the DATA and DATA outputs (Pin is internally pulled up).