2
FEATURES
›› Meets the requirements of MIL-STD-1553B
›› Centre-tapped primary and secondary for increased
flexibility
›› Choice of transformation ratios to accommodate
the complete range of C-MAC transceivers and
remote terminals, in either transformer or direct-
coupled configurations
›› Leaded and surface mount versions available
MIL-STD-1553 and 1760
DATA BUS TRANSFORMERS
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Fig. 1 Connection Diagram
NOTE: For surface mount variant append part number with ‘-SM’
1553 TERMINATED
DATA BUS
Cable characteristic
impedance = ZO
ZO = 70 ohms nominal
FAULT ISOLATION
RESISTORS: R = 0.75 ZO
(supplier by user)
COUPLING
TRANSFORMER
STUB length 20 ft max
(Transformer-coupled only)
ISOLATION
TRANSFORMER
(Transformer-coupled only)
BUS
TRANSCEIVER
FC1553TI
R R
1
8
1: 2
57
13
2
13
18
4
TXDATAOUT
RXDATAIN
NRXDATAIN
NTXDATAOUT
R R
48
13
2
TXDATAOUT
RXDATAIN
NRXDATAIN
NTXDATAOUT
ZO
TRANSFORMER-COUPLED DIRECT-COUPLED
ZO
Pins
(1-3) : (5-7)
Pins
(1-3) : (4-8) (1-2)+(2-3) : (5-6)+(6-7) : (4-6)+(6-8)
FC1553TI 2 : 1 1.41 : 1 1+1 : 0.5+0.5 : 0.71+0.71
FC1553TI (12V) 1.66 : 1 1.20 : 1 1+1 : 0.6+0.6 : 0.83+0.83
FC1553TI (V) 1.41 : 1 1 : 1 1+1 : 0.71+0.71 : 1+1
FC1553TI (5V) 0.67 : 1 0.47 : 1 1+1 : 1.5+1.5 : 2.12+2.12
FC1553TI (5VX) 0.57 : 1 0.40 : 1 1+1 : 1.75+1.75 : 2.5+2.5
FC1760TI 0.60 : 1 0.42 : 1 1+1 : 1.67+1.67 : 2.38+2.38
TRANSFORMATION RATIOS
C-MAC Part No.
17
5 3
f = 1MHz1 Vin = 4Vpk-pk
Vin Vcm CMRR = 20 log10 Vcm
Vin
Operating Conditions
Electrical Characteristics
1
3
f = 75kHz1 Vin = 8Vpk-pk
Vin V1Zp = x 100 ohms
V2
V1
100R
V2
1
3
f = 250kHz1 Vin = 27Vpk-pk
Vin
360R
5
7
Vout overshoot = Vor
droop = x 100%
ED
EP
Fig.2 Open-circuit Primary Impedence Fig. 3 Common Mode Rejection Ratio
Fig. 4 Overshoot and Ringing, droop
Vout
ED
Ep
Ep
ED
Vor
Vor
Symbol Parameter Min Typical Max Unit
f Operating Frequency Range 75 1000 kHz
TCO Operating Case Temperature Range -55 +125 deg C
TCS Storage Temperature Range -55 +150 deg C
VWP Peak Working Voltage 50 V
Symbol Parameter Test Conditions Min Typical Max Unit
TR Turns Ratio Tolerance ±3 %
CMRR Common Mode Rejection Ratio Fig. 2 45 50 dB
ZPOpen-Circuit Primary Impedance Fig. 3 3 kΩ
or Overshoot and Ringing Fig. 4 ±1 Vpk-pk
EDDroop Fig. 4 10 20 %
I Leakage Industance (1-3) with
(4-8) short circuit 5 uH
RDC DC Winding Resistance (1-3), 10mA 1 3 Ω
RIW Interwinding Resistance (2-6), 100V 50 MΩ
CIW Interwinding Capacitance (2-6), 0.1V, 10kHz 70 pF
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MIL-STD 1553 and 1760 DATA BUS TRANSFORMERS
12.7
(0.5)
nom
7.6
(0.299)
max
10.0
(0.394)
min
1
2
3
4
5
6
7
8
Plug-in
Surface mount
3
2
14
5
6
7
8
16.5
(0.65) 2.54
(0.10)
typ
TOP
VIEW
16.5 (0.65)
BOTTOM
VIEW
3.0 x 1.25 TYP
(0.118 x 0.049)
in 8 places
5.0 max
(0.197)
3
2
14
5
6
7
8
15.9
(0.626)
max
2.54
(0.10)
typ
Diam. 0.5
(0.97)
nom
TOP
VIEW
15.9 (0.626) max
APPLICATION NOTES
›› Refer to the appropriate C-MAC transceiver data sheet for the correct selection of
transformer
›› In ‘transformer-coupled’ configuration, the chosen transformer forms the ‘isolation
transformer’, see Fig.1
›› In ‘direct coupled’ configuration, the same transformer forms the ‘coupling
transformer’, see Fig.1
›› Always use FC1553TI for the ‘coupling transformer’ in the ‘transformer-coupled’
configuration, see Fig. 1
›› For PCB layout the transformer connections should be short and balanced to en-
sure the series inductance and resistance are minimised
For further information contact us at:
C-MAC MicroTechnology
South Denes, Great Yarmouth, Tel: +44 (0) 1493 743 100
Norfolk, NR30 3PX, UK Email: info@cmac.com
SAS6102 Issue 2 April 2008
MIL-STD 1553 and 1760 DATA BUS TRANSFORMERS OUTLINE DRAWINGS
