BU-63705
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®
MIL-STD-1553 DUAL REDUNDANT
REMOTE TERMINAL HYBRID
SPACE-RT-II
FEATURES
•
Drop in Replacement for BU-65142
•
Radiation Tolerant & Radiation
Hardened versions for Space Based
Applications
•
Complete Integrated Remote
Terminal Including:
– Low-Power Transceivers
– Complete RT Protocol
•
Multiple Ordering Options;
+5V (Only), +5V/-15V, and +5V/-12V
•
Direct Interface to Systems with
No Processor
DESCRIPTION
The BU-63705, “SPACE-RT-II,” is a Hi-Rel radiation tolerant complete
dual redundant MIL-STD-1553 Remote Terminal Unit (RTU). The
SPACE-RT-II is a drop in Replacement for the BU-65142. The device
is based upon two DDC custom ICs, which includes two monolithic
bi-polar low power transceivers and one RICMOS™ protocol chip
containing data buffers and timing control logic. It supports all 13
mode codes for dual redundant operation, any combination of which
can be illegalized.
Parallel data transfers are accomplished with a DMA type handshak-
ing, compatible with most CPU types. Data transfers to/from memory
are simplified by the latched command word and word count out-
puts.
Error detection and recovery are enhanced by BU-63705 special fea-
tures. A 14-bit built-in-test word register stores RTU information, and
sends it to the Bus Controller in response to the Mode Command
Transmit Bit Word. The BU-63705 performs continuous on-line wrap-
around self-test, and provides four error flags to the host CPU. Inputs
are provided for host CPU control of 6 bits of the RTU Status Word.
Its integrated hermetic package, -55°C to +125°C operating tempera-
ture range, and complete RTU operation make the BU-63705 ideal for
MIL-STD-1553 applications requiring hardware or microprocessor
subsystems.
•
High Reliability Screening
WARNING: ITAR CONTROLLED PRODUCT
The product(s) referenced on this data sheet or product
brief and certain related technical data is subject to the
U.S. Department of State International Traffic in Arms
Regulations (ITAR) 22 CFR 120-130 and may not be
exported without the appropriate prior authorization from
the Directorate of Defense Trade Controls, United States
Department of State. This datasheet includes only basic
marketing information on the function of the product and
therefore is not considered technical data as defined in
22CFR 120.10.
FOR MORE INFORMATION CONTACT:
Data Device Corporation
105 Wilbur Place
Bohemia, New York 11716
631-567-5600 Fax: 631-567-7358
www.ddc-web.com
Technical Support:
1-800-DDC-5757 ext. 7771
All trademarks are the property of their respective owners.
© 2005 Data Device Corporation
Data Device Corporation
www.ddc-web.com
DATA
BUS A
ENCODER/
DECODER
BIT
PROCESSOR
BUFFER
TRANSFER
CONTROLS
TRANSCEIVER
DB0-DB15
BUF ENA
WATCHDOG
TIMEOUT
DTREQ
DTGRT
DTACK
DTSTR
R/W
DATA
BUS B
ENCODER/
DECODER
BIT
PROCESSOR
TRANSCEIVER
CURRENT
WORD
COUNTER
M
U
X
A0-A4
A5-A10
COMMAND
LATCH
2
RT ADDRESS
+
PARITY
PROTOCOL
SEQUENCER
AND
CONTROL
LOGIC
STATUS
REGISTER
16 MHz CLOCK
DAT/CMD
ILL CMD (ME)
SS REQ
ADBC
RT FLAG
SS BUSY
SS FLAG
ERROR FLAGS
MESS ERR
RT FAIL
HS FAIL
RTADD ERR
TIMING FLAGS
NBGT
INCMD
BITEN
STATEN
GBR
DDC CUSTOM CHIP
DS-BU-63705-L
11/10
FIGURE 1. BU-63705 SERIES BLOCK DIAGRAM
TABLE 1. SPACE-RT-II SERIES SPEC’S
PARAMETER
ABSOLUTE MAXIMUM RATING
Supply Voltage
Logic +5V
Transceiver +5V
-15V (BU-63705X1)
-12V (BU-63705X2)
Receiver Differential Input Voltage
Logic
Voltage Input Range for +5V
RECEIVER
Differential Input Impedance
(BU-63705 X1/X2) (DC to 1 MHz)
Differential Input Resistance
(BU-63705X3)
Input Threshold Level
Direct Coupled (BU-63705 X1/X2)
Transformer Coupled, Measured on
Stub (BU-63705X3)
CMRR (DC to 2 MHz)
CMV (DC to 2 MHz)
TRANSMITTER
Differential Output Voltage
Direct Coupled Across 35
Ω,
Measured on Bus
Transformer Coupled Across 70Ω,
Measured on Stub
Output Noise, Differential (Direct
Coupled)
Output Offset Voltage, (Transformer
Coupled Across 70 ohms)
Rise/Fall Time
LOGIC
V
IH
(V
CC
=5.5V)
V
IL
(V
CC
= 4.5V)
I
IH
(V
CC
= 5.5V, V
IN
= 2.7V)
16MHz_IN
All other inputs
I
IL
(V
CC
= 5.5V, V
IN
= 0.0V)
16MHz_IN
All other inputs
V
OH
(V
CC
= 4.5V, I
OH
= max)
V
OL
(V
CC
= 4.5V, I
OL
= max)
I
OH
(V
CC
= 4.5V) (Note 1)
I
OL
(V
CC
= 4.5V)
C
IN
(f = 1MHz)
C
IO
(f = 1MHz)
POWER SUPPLY REQUIREMENTS
+5V Logic Power
Logic Current Drain
BU-63705X1
+5V (Ch. A, Ch. B)
-15V (VA, VB)
BU-63705X2
+5V (Ch. A, Ch. B)
-12V (VA, VB)
BU-63705X3 (+5V Only)
+5V (Ch. A, Ch. B)
MIN
TYP
MAX
UNITS
TABLE 1. SPACE-RT-II SERIES SPEC’S (CONT)
PARAMETER
POWER SUPPLY REQUIREMENTS
(CONTINUED)
Current Drain
BU-63705X1
-15V (Ch.A & Ch. B)
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
BU-63705X2
MIN
TYP
MAX
UNITS
-0.5
-0.5
-18.0
-18.0
-0.5
4.0
2.5
0.28
0.200
6.5
7.0
0.3
0.3
40.0
Vcc+0.5
V
V
V
V
Vp-p
V
kΩ
KΩ
60
108
175
270
mA
mA
mA
mA
1.20
0.860
Vp-p
Vp-p
dB
V
-12V (Ch.A & Ch. B)
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
BU-63705X3
60
120
185
305
mA
mA
mA
mA
40
±10
+5V (Ch.A & Ch. B)
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
POWER DISSIPATION (NOTE 2)
Total Hybrid
BU-63705X1
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
BU-63705X2
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
BU-63705X3
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
Hottest Die
BU-63705X1
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
BU-63705X2
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
BU-63705X3
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
125
230
335
545
mA
mA
mA
mA
6
18
7
20
9
27
10
Vp-p
Vp-p
mVp-p,
diff
mVp-p,
diff
nsec
V
V
µA
µA
µA
µA
V
V
mA
mA
pF
pF
-250
100
2
150
+250
300
1.475
1.856
2.238
3.000
1.295
1.680
2.065
2.895
0.687
0.92
1.15
1.60
0.680
1.010
1.350
2.030
0.290
0.540
0.790
1.290
0.280
0.510
0.750
1.220
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
0.8
-10
-400
-10
-600
4
+10
-20
+10
-60
0.5
-8
8
50
50
20
30
4.5
5.0
5.5
115
5.5
-14.25
5.5
-11.4
5.25
V
mA
V
V
V
V
V
4.5
-15.75
4.5
-12.6
4.75
5.0
-15.0
5.0
-12.0
5.0
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TABLE 1. SPACE-RT-II SERIES SPEC’S (CONT)
PARAMETER
CLOCK INPUT
Frequency
• Nominal Value
• Long Term Tolerance
1553A Compliance
1553B Compliance
• Short Term Tolerance, ONE sec
1553A Compliance
1553B Compliance
• Duty Cycle
16 MHz
1553 MESSAGE TIMING
• RT -to - RT Response Timeout
• RT Response Time
• Transmitter Watchdog Timeout
THERMAL
• Thermal Resistance, Junction-to
-Case, Hottest Die (ThetaJC)
• Operating Junction Temperature
• Storage Temperature
• Lead Temperature
(soldering 10 sec.)
PHYSICAL CHARACTERISTICS
Size
78-pin Ceramic QIP (BU-63705D)
78-pin Ceramic Flat Pack
(BU-63705F)
Weight
Notes (for TABLE 1):
1. Minus sign indicates the direction of current flow.
2. Power dissipation specifications assume a transformer coupled configuration,
with external dissipation (while transmitting) of 0.14 watts for the active isolation
transformer, 0.08 watts for the active coupling transformer, 0.45 watts for each of
the two bus isolation resistors, and 0.15 watts for each of the two bus termination
resistors.
MIN
TYP
MAX
UNITS
16
-0.01
-0.10
-0.001
-0.01
40
0.01
0.10
0.001
0.01
60
MHz
%
%
%
%
%
The BU-63705 allows the subsystem host CPU to control 6 of the
bits in the RTU status word. Of particular interest is the Illegal
Command input which may be used to set the message error bit
and illegalize any command word. The BU-63705 provides four
error flags to the subsystem host CPU for evaluating its condition.
In addition a continuous on-line self-test is performed by the
BU-63705 on every transmission. The last Transmitted Word of
every message is wrapped around into the decoder and com-
pared with the Actual Word. Any discrepancy is flagged as an
error.
HIGH-REL SCREENING / RADIATION TOLERANCE
Please contact your local DDC representative for further infor-
mation on the High Reliability screening options and the
Radiation Tolerance specifications.
17.5
8
18.5
768
19.5
10
µs
µs
µs
TIMING
Interfacing the subsystem host CPU to the BU-63705 is simple
and compatible with most microprocessors. FIGURES 4 and 5
illustrate typical MIL-STD-1553 messages for Transmit data and
Receive data. FIGURES 6 and 7 illustrate RT to RT transfers. In
each case NBGT identifies the start of the message, and INCMD
identifies that a command is being processed. The handshake
sequence DTREQ, DTGRT, and DTACK is used to transfer each
word over the parallel data highway. DTSTR and RD/WR are
used to control transfers to RAM memory. GBR identifies a “good
block received”, when a received message has passed all valida-
tion checks and has the correct word count. BUFENA (Buffer
Enable) must be applied to enable the internal tri-state buffers.
7.55
-55
-65
150
150
300
°C/W
°C
°C
°C
1.80 x 2.10 x 0.21
(45.7 x 53.3 x 5.3)
1.80 x 2.10 x 0.21
(45.7 x 53.3 x 5.3)
1.7
(48.2)
in
(mm)
in
(mm)
oz
(g)
ERROR FLAGS
Four error flags are output to the subsystem to provide informa-
tion on the condition of the BU-63705.
1. The ME (Message Error) line goes LOW if any of the follow-
ing error conditions exist:
• format error
• word count error
• invalid word
• sync error
• RT to RT address error
• T/R bit error
2. The RTFAIL (Remote Terminal Failure) line goes LOW when-
ever the results of a continuous wraparound self-test shows
a discrepancy, or a transmitter watchdog timeout has
occurred.
3. The HSFAIL (Handshake Failure) line goes LOW whenever
the system does not issue a DTGRT in response to a
DTREQ before timing-out.
4. The RTADR ERR (RT Address Error) line goes LOW when-
ever the sum of the 5 address lines and parity lines show a
parity error (the terminal will not respond to commands while
this error condition exists).
INTRODUCTION
The BU-63705 is a complete dual redundant Remote Terminal
Unit (RTU). It is fully compliant with MIL-STD-1553B and supports
all message formats. As shown in FIGURE 1, it includes 2 trans-
ceivers and a custom chip containing 2 encoders / decoders, 2 bit
processors, an RTU protocol sequencer and control logic, output
latches, and buffers. With the addition of 2 data bus transformers,
the BU-63705 is ready for connection to a MIL-STD-1553 data
bus.
Data is transferred to and from the subsystem host CPU over a
16-bit parallel highway, which is isolated by a set of bi-directional
buffers. All transfers are made with a DMA type handshake sequence
of request, grant and acknowledge. Read/write and data strobes are
provided to simplify interfacing to external RAM. Also simplifying the
RAM interface is the availability of a latched command word and an
auto-incrementing word counter. These signals may be used as an
address to map the data directly to and from RAM.
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DIRECT COUPLED (SHORT STUB)
1.4:1
DATA BUS
Z
0 (70 to 85
Ω)
55
Ω
1 FT MAX
+5V
-15V
BU-63705X1
39 VPP
ISOLATION
TRANSFORMER
28 VPP
55
Ω
OR
TRANSFORMER COUPLED (LONG STUB)
2:1
1:1.4
20 FT MAX
8
4
1
3
0.75 Z
0
28 VPP
0.75 Z
0
39 VPP
ISOLATION
TRANSFORMER
20 VPP
COUPLING
TRANSFORMER
DIRECT COUPLED (SHORT STUB)
1:0.83
55
Ω
1 FT MAX
+5V
-12V
BU-63705X2
33 VPP
ISOLATION
TRANSFORMER
28 VPP
55
Ω
OR
TRANSFORMER COUPLED (LONG STUB)
1:0.67
1:1.4
20 FT MAX
8
4
1
3
0.75 Z
0
28 VPP
0.75 Z
0
33 VPP
ISOLATION
TRANSFORMER
20 VPP
COUPLING
TRANSFORMER
DIRECT COUPLED (SHORT STUB)
1:2.5
55
Ω
1 FT MAX
+5V
BU-63705X3
11.6 VPP
ISOLATION
TRANSFORMER
28 VPP
55
Ω
OR
TRANSFORMER COUPLED (LONG STUB)
1:1.79
1:1.4
20 FT MAX
8
4
1
3
0.75 Z
0
28 VPP
0.75 Z
0
11.6VPP
ISOLATION
TRANSFORMER
20 VPP
COUPLING
TRANSFORMER
Z
0
(70 to 85
Ω)
FIGURE 2. INTERFACE TO 1553 BUS
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DS-BU-63705-L
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