CIRCUIT TECHNOLOGY

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eroflex Circuit T

echnology

 Data Bus Modules For The Future © SCD4418D REV A 9/24/97

Features

· ACT4418 Dual Transceivers meets

MIL-STD-1553A&B, Macair A3818,
A4905, A5232 and A5690 Specs

· ±12 Volt Power Supply Operation

· Voltage source output for higher bus

drive power

· Molded Plug-in package

· Monolithic construction using linear

ASICs

· Variable TX Amplitude

· Processed and Screened to Mil-STD-883

Specs for Industrial temperature range

General Description

The Aeroflex Circuit Technology

ACT4418D is a new generation
monolithic transceivers which provide
full compliance with Macair and MIL-
STD-1553 data bus requirements
while providing variable amplitude
control.

The ACT4418D performs the front-

end analog function of inputting and
outputting data through a transformer
to a MIL-STD-1553 or Macair data
bus. The ACT4418D can be consid-
ered 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 ACT4418D
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.

Variable amplitude is adjusted with

010 Vdc on the control pin.

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 data
bus side with two 52.5 Ohm fault iso-
lation resistors, and loaded by two 70

Block Diagram (without Transformer)

SHAPING

OUTPUT
STAGE

COMP.

ACTIVE
FILTER

INPUT

AMP

DRIVER

TX DATA IN

TX INHIBIT

+5V

RX DATA IN

STROBE

TX DATA OUT

RX DATA OUT

-12V

+12V

V+

V-

AMP CONTROL

One Channel

GROUND

ACT4418 Molded Dual Variable Amplitude Transceivers

& MIL-STD-1553

for MACAIR A3818, A5690, A5232, A4905

Aeroflex Circuit Technology

SCD4418D Rev A 9/24/97 Plainview NY (516) 694-6700

Ohm terminations plus additional
receivers, the data bus signal pro-
duced is 7.5 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 high impedance and is
"removed" from the line. In addition,
an overriding "INHIBIT" input pro-
vides for the removal of the trans-
mitter 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 Wave-
forms,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.

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 trans-
former (See Figure 5 for transformer
data and typical connection).

A low level at the Strobe input

inhibits the DATA and DATA out-
puts. If unused, a 2K pull-up to +5
Volts is recommended

DATA IN

INHIBIT

LINE TO LINE

OUTPUT

NOTES:

2. DATA and DATA inputs must be complementary waveforms or 50% duty cycle average, with no delays between them.
3. DATA and DATA must be in the same state during off time (both high or low).

Figure 1 Transmitter Logic Waveforms

Figure 2 Receiver Logic Waveforms

Note overlap

NOTE

Waveforms shown are for normally low devices. For normally high receiver output

devices, the receiver outputs are swapped as shown by the dashed lines

level

LINE TO LINE
INPUT

DATA OUT

1. Line to line waveforms illustrate Macair signals, MIL-STD-1553 signals are trapezoidal

Aeroflex Circuit Technology

SCD4418D Rev A 9/24/97 Plainview NY (516) 694-6700

Absolute Maximum Ratings

Operating case temperature

-40°C to +85°C

Storage case temperature

-65°C to +150 °C

Power supply Voltages

±12 V P.S. to ±15V MAX

+5 V P.S. to +7V MAX

Logic input Voltage

-0.3 V to +5.5 V

Receiver differential input

±40 V

Receiver input voltage (common mode)

±10V

Transmitter peak output current

110 mA

Total package power dissipation over the full operating
case temperature range (100% duty cycle)

1.65 mW

Maximum

150°C

Maximum junction to air temperature rise

(100 % duty cycle)

60°C

Maximum Junction-Air thermal resistance for free air

36°C/W

Electrical Characteristics, Transmitter Section

Input Characteristics, TX DATA in or TX DATA in

Parameter

Condition

Symbol

Min

Typ

Max

Unit

"0" Input Current

= 0.4 V

ILD

-0.2

-0.4

"1" Input Current

= 2.7 V

IHD

1.0

µA

"0" Input Voltage

IHD

0.7

"1" Input Voltage

IHD

2.0

Inhibit Characteristics

"0" Input Current

= 0.4V

ILI

-0.2

-0.4

"1" Input Current

= 2.7V

IHI

1.0

µA

"0" Input Voltage

ILI

0.7

"1" Input Voltage

IHI

Delay from TX inhibit(0

1) to inhibited output

Note 1

DXOFF

400

500

Delay from TX inhibit, (1

0) to active output

Note 1

DXON

400

500

Differential output noise, inhibit mode

NOI

0.8

mV p-p

Differential output impedance (inhibited)

Note 2

Output Characteristics

Differential output level at point BB' Fig 5,

Vcont = 10 Vdc, See Fig 3 for control volt-
age versus output level

= 140

V p-p

Rise and fall times

(10% to 90% of p-p output)

200

250

300

Output offset at point A-A'on Fig 5, 2.5 µS
after midpoint crossing of the parity bit of
the last word of a 660 µS message

= 35

±90

mV peak

Delay from 50% point of TX DATA or TX
DATA input to zero crossing of differential
signal. (note 1.)

DTX

330

450

Aeroflex Circuit Technology

SCD4418D Rev A 9/24/97 Plainview NY (516) 694-6700

Electrical Characteristics, Receiver Section

Parameter

Condition

Symbol

Min

Typ

Max

Unit

Differential Input Voltage Range

IDR

V p-p

Input Common Mode Voltage Range

Note 1

ICR

V p-p

Common Mode Rejection Ratio Note 3

Note 1

CMRR

Strobe Characteristics (Logic "O" inhibits output)

"0" Input Current

=0.4 V

-0.2

-0.4

"1" Input Current

=2.7V

-1.0

+40

µA

"0" Input Voltage

0.7

"1" Input Voltage

2.0

Strobe Delay (turn-on or turn-off)

Note 1.

150

Threshold Characteristics (Sinewave input )

Internal Threshold Voltage (referred to the
bus)

100KHz-

1 MHz

0.60

0.8

1.05

P-P

Output Characteristics, RX DATA and RX DATA

"1" State

= -0.4 mA

2.5

3.6

"0" State

= 4 mA

0.35

0.5

Delay, (average)from differential input zero
crossings to RX DATA and RX DATA output
50% points

Note 1

DRX

300

450

Power Data

Power Supply Currents (Typical) Per Channel See Figure 4 (Power supplies set at +12V, -12V, +5V)

Duty Cycle

-V

Transmitter Standby

30mA

50mA

25mA

25% duty cycle

Note 1

50mA

70mA

50% duty cycle

75mA

95mA

100% duty cycle Note 1

120mA

140mA

Note: Typical currents for V

140

= 30V

Recommended Power Supply Voltage Range

+11.4 Volts to +12.6 Volts

-V

-11.4 Volts to -12.6 Volts

Logic

+4.5 Volts to + 5.5 Volts

Aeroflex Circuit Technology

SCD4418D Rev A 9/24/97 Plainview NY (516) 694-6700

NOTES
1. Characteristics guaranteed by design, not production tested.
2. Power on or off, measured from 75KHz to 1MHz at point A-A' and transformer self impedance of 3K

minimum at 1 MHz.

3. Specifications apply over the temperature range of -40°C to +85°C (Case Temperature) unless otherwise

noted.

4. All typical values are measured at +25°C.

Figure 3 Transmitter (TX) Output Amplitude

Figure 4 Transmitter (TX) Output offset

Figure 5 Typical Transformer Connection

Figure 6 Typical Hybrid Power Dissipation

0 10 20 30 40 50 60 70 80 90 100

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

DUTY CYCLE, PERCENT

I
S

I
P

I
O

OUTPUT OFFSET

LAST BIT

2.5 µsec

*Offset measured at point A-A' in Fig 5

N1:N2

TX DATA OUT

RX DATA IN

52.5

Ctr

tap

Transformer turns ratios:
N1:N2 = 1:1
N1:N3 = 1:0.707
Use Aeroflex 25T1553-1

N1:N3 for
stub

coupling

0 Volts

Magnified View

vs Control Voltage

0 1 2 3 4 5 6 7 8 9 10

CONTROL VOLTAGE

I
T

Typical

Slope = 3V

/Vdc

@ BB'

Vdc

(Total hybrid with one channel transmitting

and the other not powered 100% Duty Cycle)

Total Hybrid Input

Power

C1 & C2 are > 0.47µF,
BX Ceramic Capacitors.

vs Duty Cycle (Total with one channel

transmitting and the other not powered)

For V

= 30 V at 140

Typical Hybrid

Dissipation

3.25

1.65

Aeroflex Circuit Technology

SCD4418D Rev A 9/24/97 Plainview NY (516) 694-6700

Figure 6 Lead Numbers & Functions

ACT4418D

Pin

Function

Channel

Tx INHIBIT

Tx DATA IN

STROBE

CONTROL VOLTAGE

+5v

Rx DATA OUT

TxRx DATA OUT

Tx INHIBIT

Tx DATA IN

STROBE

CONTROL VOLTAGE

GROUND

Rx DATA OUT

TxRx DATA OUT

Aeroflex Circuit Technology

SCD4418D Rev A 9/24/97 Plainview NY (516) 694-6700

Ordering Information

Model No.

Receiver Data level

Case

Specs.

ACT4418D

Normally Low

24 Pin Plug In

1553 & Macair

Specifications subject to change without notice.

1.366

MAX

.560

REF

.170

.244

1.195
1.205

.160

.100

.600

.008

Package Outline

The information contained in this data sheet is believed to be accurate; however, Aeroflex Circuit Technology. assumes no

responsibility for its use, and no license or rights are granted by implication or otherwise in connection the

rewith.

Aeroflex Circuit Technology
35 South Service Road
Plainview New York 11803

Telephone: (516) 694-6700
FAX: (516) 694-6715

Toll Free Inquiries: 1-(800)THE-1553

C I R C U I T T E C H N O L O G Y

Part Number ACT4418