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www.aeroflex.com/act1.htm
ACT 4487 DUAL TRANSCEIVER
FOR MIL-STD-1553/1760
Features
• +5 / ±15 Volt Supply Operation
• Low Power Dissipation
• Small Size & Light Weight
• Dual Transceivers Saves Space & Cost
• 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
• DESC SMD (Standard Military Drawing)
TX DATA IN
TX DATA
TX INHIBIT IN
+5V (VL)
+15V (VCC)
-15V (V
GND1
GND2
GND3
RX DATA
RX DATA IN
CASE
RX STROBE IN
IN
EE)
IN
DRIVER
INPUT
AMPLIFIER
ACTIVE
FILTER
REFERENCE
ACTIVE
FILTER
OUTPUT
STAGE
COMP.
COMP.
Block Diagram (Without Transformer)
TX DATA OUT
TX DATA
OUT
OUT
RX DATA
RX DATA OUT
CIRCUIT TECHNOLOGY
General Description
The Aeroflex Circuit
Technology ACT 4487 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 ACT4487 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.
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
1.4:1 ratio transformer, isolated on
the data bus side with two 52.5
Ohm fault isolation resistors, and
loaded by two 70 Ohm
eroflex Circuit Technology – Data Bus Modules For The Future © SCD4487D REV B 3/10/98
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terminations, the data bus signal is
Note overlap
typically 7.5 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 for the removal of the
transmitter output from the line. A
logic “1” signal applied to the
“INHIBIT” takes priority over the
condition of the data inputs and
disables the transmitter (See
Transmitter Logic Waveform,
Figure1). The Transmitter may be
safely operated for an indefinite
period with the bus (point A) short
circuited at 100% duty cycle.
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 negative excursions of the input
beyond a pre-determined threshold
, and represent positive
(See Receiver Logic Waveform,
Figure 1 — Transmitter Logic Waveforms Idealized
DATA IN
DATA IN
Figure 2).
The pre-set internal thresholds
will detect data bus signals, point
A Figure 5, exceeding 1.20 Volts
P-P and reject signals less than
0.6 Volts P-P when used with a
transformer (See Figure 5 for
transformer data and typical
connection).
A low level at the RX Strobe
input inhibits the DATA and
DATA
outputs. If unused, a 2K
pull-up to +5 Volts is
recommended.
INHIBIT
LINE TO LINE
OUTPUT
Note:
DATA and DATA
and must be in the same state during off times (both high or low).
inputs must be complementary waveforms or 50% duty cycle average, with no delays between them,
Figure 2 — Receiver Logic Waveforms Idealized (ACT4487D)
LINE TO LINE
INPUT
STROBE
DATA OUT
DATA OUT
Aeroflex Circuit Technology SCD4487D REV B 3/10/98 Plainview NY (516) 694-6700
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Absolute Maximum Ratings
Operating case temperature -55°C to +125°C
Storage case temperature -65°C to +150°C
Power supply voltage
CC
V
VEE
VL
-0.3 V to +18 V
+0.3 V to-18 V
-0.3 V to +7.0 V
Logic input voltage -0.3 V to +5.5 V
Receiver differential input ±40 V
P-P
Receiver input voltage (common mode) ±10 V
Driver peak output current 300 mA
Total package power dissipation over the full operating
case temperature rise
(Note: Normal operation conditions require one
2.5 Watts
transceiver on and the other off)
Maximum junction to case temperature 10°C
Thermal resistance – junction to case 4°C/W
Electrical Characteristics — Driver Section
Input Characteristics, TX DATA IN or TX DATA IN (Notes 2 & 3 apply)
Parameter Condition Symbol Min Typ Max Unit
"0" Input Current VIN = 0.4 V I
"1" Input Current V
= 2.7 V I
IN
"0" Input Voltage V
"1" Input Voltage V
Inhibit Characteristics
"0" Input Current
"1" Input Current
"0" Input Voltage
"1" Input Voltage
Delay from TX inhibit, (0→1) to inhibited output From mid pt
Delay from TX inhibit, (1→0) to active output
Differential output noise, inhibit mode
Differential output impedance (inhibited) Note 1 See
Figure 5
= 0.4 V I
V
IN
=2.7V I
V
IN
inhibit to
±1.2V pt B,
See Figure 5
Point B
Point C
Output Characteristics
Differential output level, See Figure 5
See Figure 5
Rise and fall times(10% to 90% at pt A output)
See Figure 5
Output offset, Figure 3, 2.5µS after midpoint
crossing of the parity bit of the last word of a 660µS
message See Figure 5
Delay from 50% point of TX DATA or TX DATA
input
to zero crossing of differential signal. See Fig 5
Point A V
Point A
Point A
Point A t
ILD
IHD
IHD
IHD
ILI
IHI
V
ILI
V
IHI
t
DXOFF
t
DXON
V
NOI
Z
OI
Z
OI
O
t
r
V
OS
DXT
-0.1 -0.2
mA
1 40 µA
0.7
2.0 V
-0.1 -0.2
1.0 40
0.7
2.0
175 225
90 150
mA
µA
V
V
nS
nS
2 10 mV
2K
1K
6 7.5 9
Ω
Ω
V
100 160 300 nS
± 90
100 200
mV peak
nS
V
P-P
P-P
Aeroflex Circuit Technology SCD4487D REV B 3/10/98 Plainview NY (516) 694-6700
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Electrical Characteristics — Receiver Section
Parameter Condition Symbol Min Typ Max Unit
Differential Receiver Input Voltage Range
(See Figure 5, Point B)
TXFMR
1.4:1
V
Common Mode Rejection Ratio (Note 3) CMRR
"1" State – Rx Data or Rx Data
"0" State – Rx Data or Rx Data
Output IOH = -0.4 mA
Output IOI = 4 mA
V
V
Delay (average) from Differential Input Zero
Crossings to RX DATA and RX DATA
Output
t
50% points
Input Threshold Voltage (referred to the bus)
100KHz–1MHz
V
Strobe Characteristics (Logic "0" Inhibits Output)
"0" Input Current VS=0.4V
"1" Input Current V
"0" Input Voltage
"1" Input Voltage V
Strobe Delay (Turn-on or Turn-off)
=2.7V
S
IDR
OH
OL
DXT
TH
I
IL
I
IH
V
t
SD
40
V
P-P
45 dB
2.5 3.7 V
0.35
0.5
V
270 400 nS
0.60
0.75
-0.1
IL
IH
2.0
1.20 V
-0.2
1 +40
0.7
50 100
P-P
mA
µA
V
V
nS
Power Data
Power Supply Currents – Per Channel – See Figure 4
I
CC
I
I
I
I
I
I
I
EE
I
L
CC
EE
I
L
CC
EE
I
L
CC
EE
I
L
Transmitter Standby
25% duty cycle
50% duty cycle
100% duty cycle
Power Supply Voltages
V
CC
±15V Operating Power Supply Voltage Range
+5V
Operating Power Supply Voltage Range) V
VEE
Note 1. Power on or off, measured from 75KHz to 1MHz at point A and transformer self impedance of 3KΩ minimum
at 1MHz.
Note 2: Power Supplies: ±15 Volts ±0.75 V & +5 Volts ±0.5 V, bypassed by 10µF (Tantalum recommended)
Capacitor minimum. All measurements & specifications apply over the temperature range of -55°C to +125°C
(case temperature) unless otherwise specified.
Note 3: When measured as shown per Figure 5 with ± 10 Volt peak, line to ground, DC to 2MHz
Note 4: Typical power is measured with V
at point A = 7.5 V
BUS
P-P
+14.25
-14.25
L +4.50 +5.00 +5.50
0
12
18
45
12
18
90
12
18
180
12
18
+15.00
-15.00
1
16
30
50
20
30
100
20
30
200
20
30
+15.75
-15.75
mA
V
V
Aeroflex Circuit Technology SCD4487D REV B 3/10/98 Plainview NY (516) 694-6700
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Figure 3 – Transmitter (TX) Output Offset
POWER DISSIPATION
MILLIWATTS
Figure 5 – Typical 1553 Bus Connections
LAST BIT
Magnified View
0 Volts
2.5 µsec
OUTPUT OFFSET*
OUTPUT OFFSET
*
*Offset measured at point A in Figure 5
Figure 4 – Hybrid Power Dissipation vs. Duty Cycle
(Total hybrid with one channel transmitting
and the other not powered – 100% Duty Cycle)
3600
3200
2800
2400
2000
1600
1200
800
400
0.270
0
Note: Vcc= +15V, VEE = -15V, VL= +5V, Transformer ratio 1.4:1,
V
BUS
Typical Hybrid Input Power
Typical Hybrid
Dissipation
0 10 20 30 40 50 60 70 80 90 100
DUTY CYCLE – PERCENT
(point A) at 7.5VP-P.
2.97W
1.87W
Transformer Coupled Stub
ACT 4487
TX DATA OUT
TX DATA
OUT
RX DATA IN
RX DATA
IN
2:1
3
7
2
1
5
T1553-2
C
Zoi
Direct Coupled Stub
ACT 4487
TX DATA OUT
TX DATA
OUT
RX DATA IN
RX DATA
IN
Transformer Model use Technitrol Part# 1553-2
or equivalent
1.4:1
3
2
1
T1553-2
8
4
52.5Ω
B
52.5Ω
Zoi
1:1.4
VCM
52.5
52.5Ω
70Ω
Ω
A
A
70
Ω
Configurations and Ordering Information
ACT
Model # / Ordering Part #
ACT 4487-D DIP 5962-8757910X_ Normally Low
ACT 4487-DI DIP 5962-TBA Normally High
Aeroflex Circuit Technology SCD4487D REV B 3/10/98 Plainview NY (516) 694-6700
ACT 4487-DF FP 5962-8757910Y_ Normally Low
ACT 4487-DFI FP 5962-TBA Normally High
Specifications subject to change without notice.
Case
Style
DESC
Number
5
Rx Standby
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Figure 6 – Lead Numbers & Functions
ACT4487D
Pin
#
Function Channel
1 TX DATA OUT A
2 TX DATA
OUT A
3 GROUND 1 A
4 NC
5 RX DATA OUT A
6 STROBE A
7 GROUND 2 A
8 RX DATA
OUT A
9 CASE
10 TX DATA OUT B
11 TX DATA
OUT B
12 GROUND 1 B
13 NC
14 RX DATA OUT B
15 STROBE B
16 GROUND 2 B
17 RX DATA
OUT B
18 NC
19 V
CC B
20 RX DATA IN B
21 RX DATA
IN B
22 GROUND 3 B
23 V
EE B
24 +5 V (V
L) B
25 INHIBIT B
26 TX DATA IN B
27 TX DATA
28 V
CC A
IN B
29 RX DATA IN A
30 RX DATA
IN A
31 GROUND 3 A
32 V
EE A
33 +5 V (V
L) A
34 INHIBIT A
35 TX DATA IN A
36 TX DATA
Aeroflex Circuit Technology SCD4487D REV B 3/10/98 Plainview NY (516) 694-6700
IN A
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CIRCUIT TECHNOLOGY
Model ACT4487D Dual In Line
.097
1.90 MAX
1.70
0.085
36
0.78
MAX
Pin 1 & ESD
0.24
MIN
Designator
0.018 DIA.
±0.002
Model ACT4487D Flat Package
0.78 MAX
19
1.90 MAX
19
0.600
18
0.21MAX
18
0.015
±0.002
0.10 Typ
0.086 R
36
4 Places
Pin 1 & ESD
0.097
0.40
MIN
Notes
1. Dimensions shown are in inches
2. Pins are equally spaced at 0.100±0.002 tolerance,
2 SIDES
non-cumulative, each row
0.175 MAX
0.065
REF
Aeroflex Circuit Technology
35 South Service Road
Plainview New York 11830
www.aeroflex.com/act1.htm
Aeroflex Circuit Technology SCD4487D REV B 3/10/98 Plainview NY (516) 694-6700
7
Designator
0.010
±0.002
Telephone: (516) 694-6700
FAX: (516) 694-6715
Toll Free Inquiries: (800) THE-1553
E-Mail: sales-act@aeroflex.com
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