CIRCUIT TECHNOLOGY
www.aeroflex.com/act1.htm
eroflex Circuit T
echnology
– Data Bus Modules For The Future © SCD4487 REV B 1/29/98
General Description
The Aeroflex Circuit
Technology ACT 4487 is a next
generation monolithic transceiver
design which provide 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.
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
terminations, the data bus signal is
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
Block Diagram (Without Transformer)
ACTIVE OUTPUT
STAGE
COMP.
COMP.
REFERENCE
ACTIVE
FILTER
INPUT
AMPLIFIER
DRIVER
TX DATA IN
TX DATA IN
TX INHIBIT IN
-15V (VEE)
RX DATA IN
RX DATA IN
RX STROBE IN
TX DATA OUT
TX DATA OUT
RX DATA OUT
RX DATA OUT
FILTER
GND3
+5V (VL)
GND1
+15V (VCC)
GND2
CASE
Features
• +5 / ±15 Volt Supply Operation
• Low Power Dissipation
• Small Size & Light Weight
• 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
ACT 4487 SINGLE TRANSCEIVER
FOR MIL-STD-1553/1760
Aeroflex Circuit Technology SCD4487 REV B 1/29/98 Plainview NY (516)694-6700
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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 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, 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.
DATA IN
DATA IN
INHIBIT
LINE TO LINE
OUTPUT
Note:DATA and DATA inputs must be complementary waveforms or 50% duty cycle average, with no delays between them,
and must be in the same state during off times (both high or low).
Figure 1 — Transmitter Logic Waveforms Idealized
Figure 2 — Receiver Logic Waveforms Idealized (ACT4487)
Note overlap
LINE TO LINE
INPUT
DATA OUT
DATA OUT
STROBE
Aeroflex Circuit Technology SCD4487 REV B 1/29/98 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
VCC
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 VP-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 2.5 Watts
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 IILD -0.1 -0.2 mA
"1" Input Current VIN = 2.7 V IIHD 1 40 µA
"0" Input Voltage VIHD 0.7 V
"1" Input Voltage VIHD 2.0 V
Inhibit Characteristics
"0" Input Current VIN = 0.4 V IILI -0.1 -0.2 mA
"1" Input Current VIN=2.7V IIHI 1.0 40 µA
"0" Input Voltage VILI 0.7 V
"1" Input Voltage VIHI 2.0 V
Delay from TX inhibit, (0→1) to inhibited output From mid pt
inhibit to
±1.2V pt B,
See Figure 5
tDXOFF 175 225 nS
Delay from TX inhibit, (1→0) to active output tDXON 90 150 nS
Differential output noise, inhibit mode VNOI 210 mVP-P
Differential output impedance (inhibited) Note 1
See Figure 5 Point B ZOI 2K Ω
Point C ZOI 1K Ω
Output Characteristics
Differential output level,
See Figure 5 Point A VO67.5 9VP-P
Rise and fall times(10% to 90% at pt A output)
See Figure 5 Point A tr100 160 300 nS
Output offset, Figure 3, 2.5µS after midpoint crossing
of the parity bit of the last word of a 660µS message
See Figure 5 Point A VOS ± 90 mV peak
Delay from 50% point of TX DATA or TX DATA input
to zero crossing of differential signal. See Fig 5 Point A tDXT 100 200 nS
Aeroflex Circuit Technology SCD4487 REV B 1/29/98 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 VIDR 40 VP-P
Common Mode Rejection Ratio (Note 3) CMRR 45 dB
"1" State – Rx Data or Rx Data Output IOH = -0.4 mA VOH 2.5 3.7 V
"0" State – Rx Data or Rx Data Output IOI = 4 mA VOL 0.35 0.5 V
Delay (average) from Differential Input Zero
Crossings to RX DATA and RX DATA Output
50% points tDXT 270 400 nS
Input Threshold Voltage (referred to the bus) 100KHz–1MHz VTH 0.60 0.75 1.20 VP-P
Strobe Characteristics (Logic "0" Inhibits Output)
"0" Input Current VS=0.4V IIL -0.1 -0.2 mA
"1" Input Current VS=2.7V IIH 1+40 µA
"0" Input Voltage VIL 0.7 V
"1" Input Voltage VIH 2.0 V
Strobe Delay (Turn-on or Turn-off) tSD 50 100 nS
Power Data
Power Supply Currents – Per Channel – See Figure 4
Transmitter Standby
ICC
IEE
IL
0
12
18
1
16
30
mA
25% duty cycle
ICC
IEE
IL
45
12
18
50
20
30
50% duty cycle
ICC
IEE
IL
90
12
18
100
20
30
100% duty cycle
ICC
IEE
IL
180
12
18
200
20
30
Power Supply Voltages
±15V Operating Power Supply Voltage Range VCC
VEE +14.25
-14.25 +15.00
-15.00 +15.75
-15.75 V
+5V Operating Power Supply Voltage Range)VL+4.50 +5.00 +5.50 V
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 VBUS at point A = 7.5 VP-P
Aeroflex Circuit Technology SCD4487 REV B 1/29/98 Plainview NY (516)694-6700
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Configurations and Ordering Information
ACT
Model # / Ordering Part # Case
Style DESC
Number Rx Standby
ACT 4487 Plug In TBA Normally Low
ACT 4487-I Plug In TBA Normally High
ACT 4487-F Flat Package TBA Normally Low
ACT 4487-FI Flat Package TBA Normally High
Figure 3 – Transmitter (TX) Output Offset
OUTPUT OFFSET*
OUTPUT OFFSET*
LAST BIT
2.5 µsec
*Offset measured at point A in Figure 5
0 Volts
Magnified View
Figure 5 – Typical 1553 Bus Connections
1.4:1
TX DATA OUT
TX DATA OUT
RX DATA IN
RX DATA IN 70Ω
70Ω
52.5Ω
Transformer Model use Technitrol Part# 1553-2
3
2
152.5Ω
8
4
2:1
TX DATA OUT
TX DATA OUT
RX DATA IN
RX DATA IN
52.5Ω
3
2
152.5Ω
7
5
1:1.4
Transformer Coupled Stub
Direct Coupled Stub
C
B
Zoi VCM
Zoi
A
A
T1553-2
T1553-2
ACT 4487
ACT 4487
or equivalent
Figure 4 – Hybrid Power Dissipation vs. Duty Cycle
0 10 20 30 40 50 60 70 80 90 100
3200
2800
2400
2000
1600
1200
800
400
0
DUTY CYCLE – PERCENT
POWER DISSIPATION
MILLIWATTS
Note: Vcc= +15V, VEE = -15V, VL= +5V, Transformer ratio 1.4:1,
VBUS (point A) at 7.5VP-P.
0.270
3600
2.97W
1.87W
Typical Hybrid
Dissipation
Typical Hybrid Input Power
Specifications subject to change without notice.
Aeroflex Circuit Technology SCD4487 REV B 1/29/98 Plainview NY (516)694-6700
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Figure 6 – Lead Numbers & Functions
ACT4487
Pin # Function
1 TX DATA OUT
2 TX DATA OUT
3 GROUND
4 NC
5 NC
6 NC
7 RX DATA OUT
8 STROBE
9 GROUND
10 RX DATA OUT
11 NC
12 NC
13 VCC
14 NC
15 RX DATA IN
16 RX DATA IN
17 NC
18 CASE
19 VEE
20 +5 V
21 TX INHIBIT
22 TX DATA IN
23 TX DATA IN
24 NC
Aeroflex Circuit Technology SCD4487 REV B 1/29/98 Plainview NY (516)694-6700
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1.385 MAX.
Plug In Package Outline
0.805
MAX. 0.600
0.200
MAX.
.015
.018
.100
.240
1.100
(11 Equal Spaces at .100)
MIN.
12
1324
Pin 1 & ESD
Designator
Flat Package Outline
1.315 MAX.
0.735
MAX.
.375
MIN.
1.100
(11 Equal Spaces at .100)
.100
.015
.010
.200
MAX.
.065
Lead 1 & ESD
Designator
12
1324
Aeroflex Circuit Technology
35 South Service Road
Plainview New York 11830
Telephone: (516) 694-6700
FAX: (516) 694-6715
Toll Free Inquiries: (800) THE-1553
www.aeroflex.com/act1.htm E-Mail: sales-act@aeroflex.com
CIRCUIT TECHNOLOGY
