Figure 3 – Transmitter (TX) Output Offset
Figure 5 – Typical 1553 Bus Connections
LAST BIT
Transformer Coupled Stub
70Ω
Magnified View
OUTPUT OFFSET
ACT 4489
*
*
TX DATA OUT
0 Volts
OUTPUT OFFSET
1 : 0.707
3
7
2
C
1 : 1.4 52.5Ω
A
TX DATA OUT
2.5 µsec
1
5
T1553-1
Zoi
V
CM
52.5Ω
RX DATA IN
RX DATA IN
*
Offset measured at point A in Figure 5
Direct Coupled Stub
Figure 4 – Hybrid Power Dissipation vs. Duty Cycle
(Total hybrid with one channel transmitting
and the other not powered – 100% Duty Cycle)
3600
3200
3.0W
POWER DISSIPATION
MILLIWATTS
2800
2400
2000
1600
1200
800
400
0
0
10
20
30
40
50
60
Typical Hybrid
Dissipation
Transformer Model use Technitrol Part# 1553-1
or equivalent
70
80
90 100
DUTY CYCLE – PERCENT
Note: Vcc= +12V, V
EE
= -12V, V
L
= +5V, Transformer ratio 1:1,
V
BUS
(point A) at 7VP-P.
Typical Hybrid Input Power
1.9W
RX DATA IN
TX DATA OUT
RX DATA IN
1
4
T1553-1
52.5Ω
Zoi
70Ω
ACT 4489
TX DATA OUT
1:1
3
8
2
B
52.5Ω
A
0.270
Configurations and Ordering Information
ACT
Model # / Ordering Part #
ACT 4489-D
ACT 4489-DI
ACT 4489-DF
ACT 4489-DFI
Specifications subject to change without notice.
Aeroflex Circuit Technology
Case
Style
DIP
DIP
FP
FP
DESC
Number
TBA
TBA
TBA
TBA
Rx Standby
Normally Low
Normally High
Normally Low
Normally High
5
SCD4489D REV A 1/30/98 Plainview NY (516) 694-6700
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
