BU-65142 series*
MIL-STD-1553 DUAL REDUNDANT
REMOTE TERMINAL HYBRID
DESCRIPTION
The BU-65142 Series is a Hi-Rel
radiation tolerent complete dual
redundant MIL-STD-1553 Remote
Terminal Unit (RTU). The device is
based upon two DDC custom ICs,
which includes two monolithic bi-
polar low power transceivers and
one RiCmos protocol containing
data buffers and timing control logic.
It supports all 13 mode codes for dual
redundant operation, any combina-
tion of which can be illegalized.
Parallel data transfers are accom-
plished with a DMA type handshak-
ing, compatible with most CPU
types. Data transfers to/from mem-
ory are simplified by the latched
command word and word count out-
puts.
Error detection and recovery are
enhanced by BU-65142 Series spe-
cial features. 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-65142
Series performs continuous on-line
wraparound self-test, and provides
four error flags to the host CPU.
Inputs are provided for host CPU con-
trol of 6 bits of the RTU Status Word.
Its integrated hermetic package,
-55°C to +125°C operating tempera-
ture range, and complete RTU opera-
tion make the BU-65142 ideal for
MIL-STD-1553 applications requiring
hardware or microprocessor subsys-
tems.
FEATURES
•
Radiation Tolerant to 300 krad
•
Complete Integrated Remote
Terminal Including:
–Dual Low-Power Transceivers
–Complete RT Protocol
•
Multiple Ordering Options;
+5V (Only), +5V/-15V, and +5V/-12V
•
Direct Interface to Systems With
No Processor
•
Space Qualified
•
High Reliability Screening
*
(Note:
BU-65142 is NOT recommended for new design, consult factory or local representative for more information)
DATA
BUS A
TRANSCEIVER
ENCODER/
DECODER
BIT
PROCESSOR
BUFFER
DB0-DB15
BUF ENA
DTREQ
DTGRT
DTACK
DTSTR
R/W
WATCHDOG
TIMEOUT
TRANSFER
CONTROLS
DATA
BUS B
TRANSCEIVER
ENCODER/
DECODER
BIT
PROCESSOR
CURRENT
WORD
COUNTER
PROTOCOL
SEQUENCER
AND
CONTROL
LOGIC
M
U
X
A0-A4
A5-A10
DAT/CMD
ILL CMD (ME)
SS REQ
ADBC
RT FLAG
SS BUSY
SS FLAG
MESS ERR
RT FAIL
HS FAIL
RTADD ERR
NBGT
INCMD
BITEN
STATEN
GBR
COMMAND
LATCH
RT ADDRESS
+
PARITY
STATUS
REGISTER
16 MHz CLOCK
ERROR FLAGS
TIMING FLAGS
DDC CUSTOM CHIP
D-RAD
FIGURE 1. BU-65142 SERIES BLOCK DIAGRAM
©
1988, 1999 Data Device Corporation
TABLE 1. BU-65142 SPECIFICATIONS
PARAMETER
ABSOLUTE MAXIMUM RATING
Supply Voltage
Logic +5V
Transceiver +5V
-15V (BU-65142, BU-65142X1)
-12V (BU-65142X1/2)
Receiver Differential Voltage
Logic
Voltage Input Range for +5V
RECEIVER
Differential Input Impedance
(DC to 1 MHz)
Differential Input Voltage
Input Threshold Level
(Direct Coupled)
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 70
Ω,
Measured on Stub
Output Noise, Differential (Direct
Coupled)
Output Offset Voltage, (Transformer
Coupled Across 70 ohms)
Rise/Fall Time
LOGIC
V
IH
V
IL
I
IH
(V
IH
=2.7V)
!
BRO ENA,
ADDRE-ADDRA(RTAD4-RTAD0),
ADDRP (connect to 30kΩ pull-up )
!
(V
IH
=2.7V) DB15 - DB0
(connect to a 45kΩ pull-up )
!
(V
IH
≥2.4V)
All Other Inputs
I
IL
(VIL=0.4V)
!
BRO ENA,
ADDRE-ADDRA(RTAD4-RTAD0),
ADDRP (connect to 30kΩ pull-up )
!
(V
IL
=0.4V) DB15 - DB0
(connect to a 45kΩ pull-up )
!
(V
IL
=≥0.7V) All Other Inputs
C
IN
(f = 1 MHz)
C
0
(f = 1 MHz)
C
I0
(f = 1 MHz)
V
OH
!
(I
OH
= 6ma), VDD = 4.5V
V
OL
!
(I
OL
= 6mA), VDD = 4.5V
MIN
TYP
MAX
UNITS
TABLE 1. BU-65142 SPECIFICATIONS (continued)
PARAMETER
POWER SUPPLY REQUIREMENTS
+5V Logic Power (BU-65142X1/2)
Current Drain
+5V (BU-65142X3)
Current Drain
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
-15V (BU-65142X1)
Current Drain
• Idle
• 50% Transmitter Duty Cycle
• 25% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
-12V (BU-65142X2)
Current Drain
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
4.75
5.0
MIN
4.5
TYP
MAX
5.5
115
5.25
125
230
335
545
-15.75
-14.25
UNITS
V
mA
V
mA
mA
mA
mA
V
-0.5
-0.5
-18.0
-18.0
7.0
7.0
0.3
0.3
40.0
7.0
V
V
V
V
Vp-p
V
kohm
-0.5
4.0
40
0.70
40
±10
1.20
Vp-p
Vp-p
dB
V
60
108
160
255
-12.6
-11.4
60
120
185
305
mA
mA
mA
mA
V
mA
mA
mA
mA
6
18
7
20
9
27
10
Vp-p
Vp-p
-250
100
2.4
150
mVp-p,
diff
+250 mVp-p,
diff
300
nsec
V
V
mA
0.7
0.04
0.2
0.04
0.2
±20
mA
µA
0.4
mA
0.4
±20
50
10
50
4.0
0.5
mA
µA
pF
pF
pF
V
V
POWER DISSIPATION (See Note)
Total Hybrid
!
BU-65142X1
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
!
BU-65142X2
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
!
BU-65142X3
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
Hottest Die
!
BU-65142X1
• Idle
• 25% Transmitter Duty Cycle
• 50% Transmitter Duty Cycle
• 100% Transmitter Duty Cycle
!
BU-65142X2
1.475
1.856
2.238
3.000
1.295
1.680
2.065
2.895
0.687
0.92
1.15
1.60
W
W
W
W
W
W
W
W
W
W
W
W
0.680
1.010
1.350
2.030
0.290
0.540
0.790
1.290
W
W
W
W
W
W
W
W
•
•
•
•
•
•
•
•
Idle
25% Transmitter Duty Cycle
50% Transmitter Duty Cycle
100% Transmitter Duty Cycle
Idle
25% Transmitter Duty Cycle
50% Transmitter Duty Cycle
100% Transmitter Duty Cycle
!
BU-65142X3
0.28
0.51
0.75
1.22
W
W
W
W
Data Device Corporation
www.ddc-web.com
2
BU-65142 SERIES
V-01/03-0
TABLE 1. BU-65142 SPECIFICATIONS (continued)
PARAMETER
MIN TYP MAX
THERMAL
• Thermal Resistance, Junction-to-
Case, Hottest Die (θJC)
• Operating Junction Temperature
• Operating Junction Temperature
• Storage Temperature
• Lead Temperature
(soldering, 10 sec.)
PHYSICAL CHARACTERISTICS
Size
78-pin Ceramic QIP (BU-65142D)
20
-55
-55
-65
150
125
150
+300
TABLE 3. HIGH RELIABILITY SCREENING OPTIONS
UNITS
°C/W
°C
°C
°C
°C
ELEMENT EVALUATION
ASSEMBLY & TEST
Particle Impact Noise
Detection (PIND)
320-Hour Burn-In
100% Non-Destructive
Wirebond Pull
Radiographic (X-Ray)
Analysis
QCI TESTING
MIL-STD-883, Method 2020 Condition A
MIL-STD-883, Method 1015
MIL-STD-883, Method 2023
MIL-STD-883, Method 2012
METHOD
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)
in
(mm)
78-pin Ceramic Flat Pack
(BU-65142F)
Weight
Extended Temperature
Cycling:
20 Cycles Including
Radiographic (X-Ray)
Testing
Moisture Content Limit of
5000 PPM
MIL-STD-883, Method 1010 Condition C
and MIL-STD-883, Method 2012
MIL-STD-883, Method 1018
Note (for TABLE 1):
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 termi-
nation resistors.
TABLE 2. BU-65142 SERIES RADIATION SPECIFICATIONS
PART
NUMBER
TOTAL
DOSE
SINGLE EVENT
UPSET
SINGLE EVENT
LATCHUP
HIGH-REL SCREENING
DDC is committed to the design and manufacture of hybrids and
transformers with enhanced processing and screening for
spaceborne applications and other systems requiring the high-
est levels of reliability. These platforms include launch vehicles,
satellites and the International Space Station.
DDC has tailored its design methodologies to optimize the fabri-
cation of space level hybrids. The intent of the design guidelines
is to minimize the number of die and wirebonds, minimize the
number of substrate layers, and maximize the space between
components. DDC’s space grade products combine analog bipo-
lar and rad hard CMOS technology to provide various levels of
radiation tolerance.
The BU-65142 is packaged in a 78-pin ceramic package. In con-
trast to Kovar (metal) packages, the use of ceramic eliminates
the hermeticity problems associated with the glass beads used
in the metal packages. In addition, ceramic packages provide
more rigid leads, better thermal properties, easier wirebonding,
and lower weight.
The production of the space level hybrids can entail enhanced
screening steps beyond DDC’s standard flow. This includes
Condition A visual inspection, SEM analysis, and element eval-
uation for all integrated circuit die. For the hybrids, additional
screening includes Particle Impact Noise Detection (PIND), 320-
hour burn-in, 100% non-destructive wirebond pull, X-ray analy-
sis, as well as Destructive Physical Analysis (DPA) testing,
extended temperature cycling for QCI testing, and a moisture
content limit of 5000 PPM. TABLE 3 summarizes the procure-
ment screening, element evaluation, and hybrid screening used
in the production of the BU-65142.
BU-65142
X1/X2
300K
Rad
5.3 x 10
-6
errors/device-day,
(LET Threshold of
59 MeV/mg/cm
2
)
5.3 x 10
-6
errors/device-day,
(LET Threshold of
59 MeV/mg/cm
2
)
Immune
BU-65142
X3
175K
Rad
Immune
TABLE 3. HIGH RELIABILITY SCREENING OPTIONS
ELEMENT EVALUATION
Visual Inspection:
Integrated Circuits
Transistors & Diodes
Passive Components
METHOD
MIL-STD-883, Method 2010 Condition A
MIL-STD-750, Method 2072 and 2073
MIL-STD-883, Method 2032 Class S
SEM Analysis for Integrated MIL-STD-883, Method 2018
Circuits
Element Evaluation:
Visual, Electrical, Wire
Bondability,24-Hour
Stabilization Bake,10
Temperature Cycles
5000 g’s constant acceleration
MIL-H-38534
240-Hour Powered Burn-In
and 1000-Hour Life Test
(Burn-In and 1000-Hour Life
Test Are Only Required For
Active Components.)
Data Device Corporation
www.ddc-web.com
3
BU-65142 SERIES
V-01/03-0
INTRODUCTION
The BU-65142 is a complete dual redundant Remote Terminal
Unit (RTU). It is fully compliant with MIL-STD-1553B and sup-
ports all message formats. As shown in FIGURE 1, it includes
2 transceivers and a custom chip containing 2 encoders, 2 bit
processors, an RTU protocol sequencer and control logic, output
latches, and buffers. With the addition of 2 data bus transform-
ers, the BU-65142 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-direction-
al 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.
The BU-65142 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-65142 pro-
vides four error flags to the subsystem host CPU for evaluating
its condition. In addition a continuous on-line self-test is per-
formed by the BU-65142 on every transmission. The last
Transmitted Word of every message is wrapped around the
decoder and compared with the Actual Word. Any discrepancy
is flagged as an error.
RT to RT address error
T/R bit error.
The RTFAIL (Remote Terminal Failure) line goes LOW
whenever the results of a continuous wraparound self-test
shows a discrepancy, or a transmitter watchdog timeout
has occurred.
The HSFAIL (Handshake Failure) line goes LOW whenev-
er the system does not issue a DTGRT in response to a
DTREQ before timing-out.
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).
STATUS REGISTER
Six inputs to the BU-65142 allow the subsystem host CPU to
control bits in the RTU status word. The Illegal Command input
may be used to set the Message Error bit in the Status Word and
suppress the transmission of data to the bus controller. This line
allows illegalization of any combination of commands. The
latched Command Word may be connected to the address pins
of an optional external PROM, which would drive the illegal
Command line LOW when it identifies a command programmed
as illegal.
STATUS REGISTER BIT ASSIGNMENTS
The SRQ (Subsystem Request) line is used to set the
Status Word service request bit.
The ADBC (Accept Dynamic Bus Control) line is used to
set the Status Word bus control bit.
The RTFLAG (RT Flag Line) is used to set the Status Word
terminal flag bit.
The BUSY (Busy) line is used to set the Status Word busy
bit, and inhibit subsystem requests for data.
The SSFLAG (SubSystem Flag) line is used to set the
Status Word subsystem (fault) flag.
TIMING
Interfacing the subsystem host CPU to the BU-65142 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 hand-
shake sequence DTREQ , DTGRT, and DTACK is used to trans-
fer each word over the parallel data highway. DTSRB and
RD/WR are used to control transfers to RAM memory. GBR
identifies a “good block received”, when a received message has
passed all validation checks and has the correct word count.
BUFENA (Buffer Enable) must be applied to enable the internal
tri-state buffers.
BUILT-IN-TEST
The BU-65142 contains a 14-bit Built-In-Test (BIT) word register
which stores information about the condition of the RTU. When a
mode code is received to transmit the BIT word, the contents of
the BIT register is transmitted over the 1553 bus.
FIGURE 3 shows the fault assigned to each bit in the BIT word.
Conditions monitored are; transmitter timeouts, loop test failures,
transmitter shutdown, subsystem handshake failure, and the
results of individual message validations.
ERROR FLAGS
Four error flags are output to the subsystem to provide informa-
tion on the condition of the BU-65142.
The ME (Message Error) line goes LOW if any of the fol-
lowing error conditions exist:
format error
word count error
invalid word
sync error
Data Device Corporation
www.ddc-web.com
4
BU-65142 SERIES
V-01/03-0
DATA BUS
Z
0 (70 to 85
Ω)
DIRECT COUPLED (SHORT STUB)
1.4:1
55
Ω
1 FT MAX
+5V
-15V
BU-65142D1
BU-65142F1
55
Ω
39 VPP
ISOLATION
TRANSFORMER
28 VPP
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-65142D2
BU-65142F2
55
Ω
33 VPP
ISOLATION
TRANSFORMER
28 VPP
OR
TRANSFORMER COUPLED (LONG STUB)
1:0.6
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-65142D3
BU-65142F3
55
Ω
11.6 VPP
ISOLATION
TRANSFORMER
28 VPP
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
FIGURE 2. INTERFACE TO 1553 BUS
Data Device Corporation
www.ddc-web.com
5
Z
0
(70 to 85
Ω)
BU-65142 SERIES
V-01/03-0
