CIRCUIT TECHNOLOGY
www.aeroflex.com
eroflex Circuit T
echnology
Data Bus Modules For The Future SCD4468D REV B 5/25/00
Features
World's smallest and lowest standby power dual
transceiver 0.3" x 1" packages
Dual transceiver meets military data bus
requirements, MIL-STD-1553 and MIL-STD-1760
Low power dissipation at full output power
Single +5V power supply
Current source output
Monolithic construction using dielectrically
isolated(D.I.)
Processed and screened to MIL-STD-883 specs
DESC SMD# 596292061 Pending
General Description
The Aeroflex Circuit Technology
Model ACT4468D is a next
generation D.I. monolithic transceiver
which provide full compliance with
MIL-STD-1553/1760 and data bus
requirements in the smallest
packages with the lowest standby
power consumption and one power
supply operation.
The dual channel Model ACT4468D
perform the front-end analog function
of inputting and outputting data
through a transformer to a
MIL-STD-1553/1760 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. Efficient
transmitter electrical and thermal
design provides low internal power
dissipation and heat rise at high as
well as low duty cycles.
Each channel of the dual transceiver
is completely separate from the other
and fully independent. This includes
power leads as well as signal lines.
Hence, each channel may be
connected to a different data bus with
no interaction.
Transmitter:
The Transmitter section accepts
bi-phase TTL data at the input and
when coupled to the data bus with a
1:2.5 transformer, isolated on the
data bus side with two 52.5 Ohm fault
isolation resistors, and loaded by two
70 Ohm terminations plus additional
receivers, the data bus signal
produced is 7.5Volts nominal P-P at
A-A'. (See Figure 5.) When both
DATA and DATA inputs are held low or
high, the transmitter output becomes
Block Diagram (without Transformer), 1/2 of unit shown
ACT4468D Dual Transceiver
SHAPING
OUTPUT
STAGE
COMP.
COMP.
REFERENCE
ACTIVE
FILTER
INPUT
AMP
DRIVER
TX DATA IN
TX DATA IN
TX INHIBIT
+5 V
STROBE
TX/RX
TX/RX
RX DATA OUT
RX DATA OUT
GROUND
ACT4468D
Dual Transceivers for MIL-STD-1553
Aeroflex Circuit Technology
2
SCD4468D REV B 5/25/00 Plainview NY (516) 694-6700
CIRCUIT TECHNOLOGY
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 Waveform,
Figure 1.)
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
Waveform. Figure 2.)
The pre-set internal thresholds will
detect data bus signals exceeding
1.150 Volts P-P and reject signals
less than 0.6 volts P-P when used
with a 1:2.5 turns ratio transformer.
(See Figure 5 for transformer data
and typical connection.)
DATA IN
DATA IN
INHIBIT
LINE TO LINE
OUTPUT
NOTES:
1.DATA and DATA inputs must be complementary waveforms or 50% duty cycle average, with no delays between them.
2.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
level devices, the receiver outputs are swapped as shown by the dashed lines.
LINE TO LINE
INPUT
DATA OUT
DATA OUT
Aeroflex Circuit Technology
3
SCD4468D REV B 5/25/00 Plainview NY (516) 694-6700
Absolute Maximum Ratings
Operating Case Temperature
-55C to +125C
Storage Case Temperature
-65C to +150C
Positive Power Supply Voltage
-0.3 V to +7.0 V
Receiver Differential Input
10 V
Receiver Input Voltage (Common Mode)
5 V
Driver Peak Output Current
650 mA
Total Package Power Dissipation over the Full Operating Case
Temperature Rise
2 Watt
(Note: Normal operation conditions require one
transmitter on and the other off at any given time.
Maximum Junction To Case Temperature Rise for the Hottest
Device
10C
Thermal Resistance, Junction to Bottom of Case
5C/W
Electrical Characteristics Driver Section
Input Characteristics, TX DATA in or TX DATA in
Parameter
Condition
Symbol
Min
Typ
Max
Unit
"0" Input Current
V
IN
= 0.4 V
I
ILD
-0.2
-0.4
mA
"1" Input Current
V
IN
= 2.7 V
I
IHD
1
40
A
"0" Input Voltage
V
IHD
0.7
V
"1" Input Voltage
V
IHD
2.0
V
Inhibit Characteristics
"0" Input Current
V
IN
=0.4V
I
ILI
-0.2
-0.4
mA
"1" Input Current
V
IN
=2.7V
I
IHI
1.0
40
A
"0" Input Voltage
V
ILI
0.7
V
"1" Input Voltage
V
IHI
2
V
Delay from TX inhibit,(0
1) to inhibited out-
put
t
DXOFF
200
300
nS
Delay from TX inhibit, (1
0) to active output
t
DXON
80
150
nS
Differential Output Noise, inhibit mode
V
NOI
2
10
mV p-p
Differential Output Impedance (inhibited)
Note 1
Z
OI
2K
Output Characteristics
Differential output level
R
L
=35
V
O
6.5
7.5
8.0
V p-p
Rise And Fall Times(10% to 90% of p-p out-
put)
t
r
100
170
300
nS
Output Offset at point A-A'on Fig 5., 2.5 S
after midpoint crossing of the parity bit of the
last word of a 660 S message
R
L
=35
V
OS
90
mV peak
Delay from 50% point of TX DATA or TX
DATA input to zero crossing of differential
signal
t
DTX
100
150
nS
Note 1. Power ON/OFF, measured from 75KHz to 1MHz at Point A-A. See Figure 5
Aeroflex Circuit Technology
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SCD4468D REV B 5/25/00 Plainview NY (516) 694-6700
Note 2. V
cc
= 5 volts 0.1 V, for all measurements unless otherwise specified.
Note 3. Specifications apply over the case temperature range of -55C to +125C unless otherwise specfied.
Note 4. All typical values are measured at +25C
Electrical Characteristics Receiver Section
Parameter
Condition
Symbol
Min
Typ
Max
Unit
Differential Voltage Range, Figure 4 Point P-P'
V
IDR
20
V peak
Common Mode Rejection Ratio
CMRR
45
dB
Strobe Characteristics (Logic "0" inhibits output)
if not used, a 1K pullup to 5 V is recommended
"0" Input Current
V
S
=0.4 V
I
IL
-0.2
-0.4
mA
"1" Input Current
V
S
=2.7V
I
IH
1
+40
A
"0" Input Voltage
V
IL
0.7
V
"1" Input Voltage
V
IH
2.0
V
Strobe Delay (turn-on)
t
SD(ON)
40
100
nS
Strobe Delay (turn-off)
t
SD(OFF)
60
100
nS
Threshold Characteristics (Sinewave input )
Input Threshold Voltage(referred to the bus)
100KHz-
1MHz
V
TH
0.60
0.8
1.15
V
p-p
Output Characteristics, RX DATA and RX DATA
"1" State
I
OH
=-0.4 mA
V
OH
2.5
3.7
V
"0" State
I
OL
= 4 mA
V
OL
0.3
0.5
V
Delay, (average)from differential input zero
crossings to RX DATA and RX DATA output
50% points
t
DRX
250
400
nS
Power Data
Maximum Currents, Per Channel (+5V)
Duty Cycle
Typ
Max
Transmitter Standby
20 mA
30 mA
25% duty cycle
155 mA
185 mA
50% duty cycle
290 mA
335 mA
100% duty cycle
560 mA
650 mA
Power Supply Voltage
+V
4.75 to 5.5 Volts
Aeroflex Circuit Technology
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SCD4468D REV B 5/25/00 Plainview NY (516) 694-6700
Configurations and Ordering Information
Model No.
DESC No.
Receiver Data level
Case
Configuration
ACT4468D
5962-92061(Pending)
Normally Low
DIP Package
Dual
ACT4468DF
5962-92061(Pending)
Normally Low
Flat Package
Dual
ACT4468DI
5962-92061(Pending)
Normally High
DIP Package
Dual
ACT4468DFI
5962-92061(Pending)
Normally High
Flat Package
Dual
Figure 3 Transmitter (TX) Output Waveform
Figure 4 Transmitter (TX) Output Offset
Figure 5 Typical Transformer Connection
6V P-P MIN
7.7V P-P MAX
90%
10%
t
r
*
t
f
*
* Rise and fall times measured at point A-A' in Fig 5
0 Volts
OUTPUT OFFSET
*
OUTPUT OFFSET
*
LAST BIT
2.5 sec
*Offset measured at point A-A' in Fig 5
1:2.5
A
A'
B'
B
TX DATA OUT
TX DATA OUT
RX DATA IN
RX DATA IN
70
70
52.5
52.5
Center
Tap
1:1.77 for
stub
coupling
0 volts
Magnified View
D.U.T
P'
P
Figure 6 Power Dissipation vs. Duty Cycle
P
O
W
E
R
D
I
S
S
I
P
A
T
I
O
N
M
I
L
L
I
W
A
T
T
S
(Total hybrid with one channel transmitting
and the other not powered)
Note: Vcc = 5 Volts, V
bus
(pt A-A') at 7.5 Volts P-P
0 10 20 30 40 50 60 70 80 90 100
1600
1400
1200
1000
800
600
400
200
0
DUTY CYCLE PERCENT
Z
O
Typical
Maximum
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