F
EATURES
•
•
•
•
•
–55°C to +85°C operation
16 to 32 VDC input
Fully isolated
Opto-coupler feedback
Switching frequency
Single and dual outputs
typical 80 kHz, variable freq.
Triple output - 200 kHz, fixed
Topology – Flyback
40 V for 50 ms transient protection
Inhibit function
Indefinite short circuit protection
Up to 70% efficiency
External capacitors required
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
MSR SERIES
4 WATT
MODELS
VDC O
UTPUT
SINGLE
DUAL
TRIPLE
5
±12
+5 & ±12
±15
+5 & ±15
•
•
•
•
•
•
Size (max.): 1.075 x 1.075 x 0.370 inches (27.31 x 27.31 x 9.40 mm).
See Section B8, case C2, for dimensions.
Weight:
20 grams maximum.
Screening: Standard or ES.See Section C2 for screening options,
see Section A5 for ordering information.
DESCRIPTION
The MSR Series™ DC/DC converters provide the high efficiencies
associated with switching regulators, yet have full isolation between
input and output. Interpoint builds the MSR converters using thick-
film hybrid technology and seals them in metal packages for military,
aerospace, and other high-reliability applications. The solder sealed
packages of the standard models pass a dip gross leak hermeticity
test. Environmentally screened models pass a fine leak hermeticity
test. See Section C2 for a complete list of screening options.
I
NHIBIT
F
UNCTION
The open collector TTL compatible inhibit terminal is referenced to
input common. Inhibiting the converter by pulling the inhibit terminal
(pin 15) low results in an input current as low as 2 mA for the
MSR2805S. The inhibit terminal has an open circuit voltage of 12
to 28 V.
S
HORT
C
IRCUIT
P
ROTECTION
Each output has current limiting circuitry for indefinite short circuit
protection providing that the case temperature does not exceed the
specified limits. Under short circuit conditions the input current is
reduced to less than full load input current and the output short
circuit current remains higher than full load output current.
C
ONVERTER
D
ESIGN
A footprint of just over one square inch makes the MSR Series
DC/DC converters one of Interpoint’s smallest converters. These
converters incorporate a flyback topology which requires a minimum
of components resulting in small package size. Single and dual
models self-oscillate at an operating frequency which is an approx-
imate inverse function of the load. At full load, the frequency is typi-
cally 80 kHz for single and dual output models. Triple output models
operate at a fixed frequency of approximately 200 kHz. A trans-
former in the forward power circuit and an opto-coupler in the feed-
back/control loop maintain input to output isolation.
M
INIMAL
H
EAT
S
INKING
The MSR Series converters’ high efficiency minimizes heat sinking
requirements, but care should be taken to remove self-generated
heat to prevent exceeding the maximum case temperature. Heat
conducting material (PCB, copper sheet, heat sink, etc.) in contact
with the converter’s baseplate can help to increase heat dissipation.
The converter can be operated at full load at a case temperature of
85°C, with the output power derated linearly to zero at 115°C.
C
ONVERTER
O
PERATION
MSR Series DC/DC converters feature an input voltage range of 16
to 32 VDC and can withstand a transient of up to 40 V for up to 50
msec. They offer a choice of five different output voltage (VDC)
configurations: +5 , ±12 , ±15, +5 main with ±12 auxiliaries, and +5
main with ±15 auxiliaries. Dual output models deliver up to 4 watts
for either balanced or unbalanced loads, however, at least 25% of
the total load should be on the positive output. The single output
model supplies up to 3.5 watts of output power while the triple output
models supply up to 3.2 watts. The high efficiency remains almost
constant over the entire input voltage range and from approximately
25% of full load to full load. This makes the MSR Series converters
ideal for either battery or aircraft power applications.
W
ARNING
: E
XTERNAL
C
APACITORS
R
EQUIRED
External capacitors are required on the outputs.
Operating the unit
without external capacitors will result in damage to the internal
circuitry.
Minimum recommended capacitor values are given in
Tables 1 and 2. For optimum performance, low ESR (Equivalent
Series Resistance) solid tantalum capacitors are required. The
specifications on the following pages are based on the use of high-
quality solid tantalums. Operation with different types of capacitors
will seriously affect performance.
B4-27
MSR SERIES
4 WATT
ABSOLUTE MAXIMUM RATINGS
Input Voltage
• 16 to 32 VDC
Output Power
• 3.2 to 4 watts depending on model
Lead Soldering Temperature (10 sec per lead)
• 300°C
Storage Temperature Range (Case)
• –-65°C to +150°C
DC/DC C
ONVERTERS
INHIBIT
Inhibit TTL Open Collector
• Logic low (output disabled)
≤
0.8 V
• Referenced to input common
• Logic high (output enabled)
≥
12 V
Open collector
TYPICAL CHARACTERISTICS
Output Voltage Temperature Coefficient
• MSR2805S 100 ppm/°C typ, 200 max.
• MSR28XXD 50 ppm/°C typ
• MSR285XXT 100 ppm/°C typ
Input to Output Capacitance
• 60 pF typical
Isolation
• 100 megohm minimum at 500 V
Conversion Frequency
• Single and dual output models, 80 kHz at
full load typical, variable frequency
• Triple output models, 200 kHz typical
fixed frequency
Inhibit Pin Voltage (unit enabled)
• 12 to 28 V
RECOMMENDED OPERATING CONDITIONS
Input Voltage Range
• 16 to 32 VDC continuous
• 40 V for 50 msec transient
Case Operating Temperature (Tc)
• –55°C to +85°C full power
• –55°C to +115°C absolute
Derating Output Power/Current
• Linearly from 100% at 85°C to 0% at 115°C
W
ARNING
: E
XTERNAL
C
APACITORS
R
EQUIRED
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, unless otherwise specified.
SINGLE AND DUAL OUTPUT MODELS
PARAMETER
1
OUTPUT VOLTAGE
OUTPUT CURRENT
OUTPUT POWER
OUTPUT RIPPLE
LINE REGULATION
LOAD REGULATION
INPUT VOLTAGE
16 TO 32 V
IN
Tc = –55°C TO +85°C
BW = DC TO 1 MHz
16 TO 32 V
IN
NO LOAD TO FULL
Tc = –55°C TO +85°C
TRANSIENT 50 ms
INPUT CURRENT
NO LOAD
FULL LOAD
INHIBITED
EFFICIENCY
CONDITIONS
MIN
4.90
—
—
—
—
—
16
—
—
—
—
65
MSR2805S
TYP
5.0
—
—
75
5
25
28
—
7
—
—
70
MAX
5.10
700
3.5
150
10
50
32
40
10
192
2
—
MIN
±11.88
—
—
—
—
—
16
—
—
—
—
67
MSR2812D
TYP
±12
—
—
75
10
12
28
—
10
—
—
70
MAX
±12.12
±167
4.0
150
20
24
32
40
15
213
15
—
MIN
±14.85
—
—
—
—
—
16
—
—
—
—
67
MSR2815D
TYP
±15
—
—
75
10
12
28
—
10
—
—
70
MAX
±15.15
±133
4.0
150
20
24
32
40
15
213
15
—
%
mA
UNITS
VDC
mA
W
mV p-p
mV
mV
VDC
V
Notes
1. External capacitors required to prevent damage to internal circuitry (see
Table 1 for specifications).
2. Dual output models deliver up to 4 watts total for balanced or unbalanced
loads, however, the positive output should carry at least 25% of the total load.
SINGLE AND DUAL OUTPUT EXTERNAL CAPACITORS
O
PERATION WITHOUT EXTERNAL CAPACITORS WILL RESULT IN DAMAGE TO THE INTERNAL CIRCUITRY
.
TABLE 1: EXTERNAL CAPACITOR REQUIREMENTS
Required
Connection
Positive Output (12 & 13) to
Output Common (8 & 9)
Positive Output (10) to
Dual Outputs
2
Output Common (8)
MSR2812D
External Capacitor (14) to
and
Output Common (8)
3
MSR2815D
Negative Output (12) to
Output Common (8)
Model
Single Output
MSR2805S
Minimum
Capacitor Value
1
220 µF, 10 V
100 µF, 25 V
100 µF, 25 V
10 µF, 25 V
POSITIVE
INPUT
1, 2
INHIBIT
15
17, 18
INPUT
COMMON
FEEDBACK
POSITIVE
OUTPUT
10
OUTPUT
COMMON
8
LOGIC
TIMING
CONTROL
SWITCH
VOLTAGE
REGULATOR
+
+
EXTERNAL
CAPACITORS
100µF
NEGATIVE
OUTPUT
12
14
10µF
+
100µF
Notes – Table 1
1. Capacitors should be high quality, low ESR components —
solid tantalum is recommended.
2. See Figure 1 for connection diagram
3. Place positive side of capacitor toward pin 8.
EXTERNAL
CAPACITOR
TERMINAL
F
IGURE
1: D
UAL
O
UTPUT
E
XTERNAL
C
APACITOR
C
ONNECTIONS
B4-28
DC/DC C
ONVERTERS
W
ARNING
: E
XTERNAL
C
APACITORS
R
EQUIRED
TRIPLE OUTPUT MODELS
PARAMETER
OUTPUT VOLTAGE
CONDITIONS
16 TO 32 V
IN
BALANCED LOAD
OUTPUT CURRENT
OUTPUT POWER
2
OUTPUT RIPPLE
3
MAIN
AUX
MAIN
AUX
Tc = –55°C TO +85°C
BW DC TO 1 MHz
MAIN
± AUX
LINE REGULATION
16 TO 32 V
IN
NO LOAD TO FULL
MAIN
± AUX
MAIN
± AUX
INPUT VOLTAGE
Tc = –55°C TO +85°C
TRANSIENT 50 ms
NO LOAD
INPUT CURRENT
FULL LOAD
INHIBITED
EFFICIENCY
MSR28512T
MIN
4.9
±11.5
10.0
1
—
—
—
—
—
—
—
—
16
—
—
—
—
65
TYP
5.0
±12.0
—
—
—
50
50
5
3
15
15
28
—
10
—
—
70
MAX
5.1
±12.5
400
±50.0
3.2
100
100
10
6
30
30
32
40
20
176
5
—
MIN
4.9
±14.5
10.0
1
—
—
—
—
—
—
—
—
16
—
—
—
—
65
MSR28515T
TYP
5.0
MAX
5.1
MSR SERIES
4 WATT
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, unless otherwise specified.
UNITS
VDC
±15.0 ±15.5
—
—
—
50
50
5
3
15
15
28
—
10
—
—
70
400
±40.0
3.2
100
100
10
7.5
30
30
32
40
20
176
5
—
%
mA
VDC
V
mV
mV
W
mV p-p
mA
LOAD REGULATION
Notes
1. External capacitors required (see Table 2 for specifications).
2. Minimum load required on main output for full power auxiliary operation.
TRIPLE OUTPUT EXTERNAL CAPACITOR
O
PERATION WITHOUT EXTERNAL CAPACITORS WILL RESULT IN DAMAGE TO THE INTERNAL CIRCUITRY
.
TABLE 2: EXTERNAL CAPACITOR REQUIREMENTS
Required
Connection
1
Positive 5 VDC Output (9) to
Output Common (6 or 7)
Minimum
Capacitor Value
2
220 µF, 10 V
POSITIVE
INPUT
1, 2
INHIBIT
15
INPUT
COMMON
17, 18
FEEDBACK
+5 OUTPUT
9
REF. &
COMP
OUTPUT
COMMON
6, 7
8
POSITIVE
AUXILIARY
OUTPUT
5
NEGATIVE
AUXILIARY
OUTPUT
220µF
EXTERNAL
CAPACITOR
Model
MSR28512T
and
MSR28515T
LOGIC
TIMING
CONTROL
SWITCH
DUAL
TRACKING
REGULATOR
Notes – Table 2
1. See Figure 2 for connection diagram.
2. Capacitors should be high quality, low ESR components —
solid tantalum is recommended.
F
IGURE
2:
T
RIPLE
O
UTPUT
E
XTERNAL
C
APACITOR
C
ONNECTIONS
B4-29
MSR SERIES
4 WATT
DC/DC C
ONVERTERS
W
ARNING
: E
XTERNAL
C
APACITORS
R
EQUIRED
PIN OUT
O
PERATION WITHOUT EXTERNAL CAPACITORS WILL RESULT IN DAMAGE TO THE INTERNAL CIRCUITRY
.
Pin
1, 2
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17, 18
1
Single Output
Positive Input
No connection
Case
No connection
No connection
No connection
Output Common
3
Output Common
3
No connection
No connection
Positive Output
3
Positive Output
3
No connection
Inhibit
No connection
Input Common
Dual Output
Positive Input
No connection
Case
No connection
No Connection
No connection
Output Common
No connection
Positive Output
No connection
Negative Output
No connection
Ext. Capacitor
Inhibit
No connection
Input Common
Triple Output
Positive Input
No connection
Case
Negative Aux. Output
Output Common Main
2
Output Common Aux.
2
Positive Aux. Output
+5 VDC Output
No connection
No connection
No connection
No connection
No connection
Inhibit
No connection
Input Common
See section B8, case C2, for dimensions.
18 17
10
1 2
9
Dot on top of cover
indicates pin one.
BOTTOM VIEW
MSR
F
IGURE
3: P
IN
O
UT
Pin Out Notes
1. Make external connection to both pins on all models.
Pins 1 and 2 positive input
Pins 17 and 18 input common
2. Pins 6 and 7 on triple output models are connected internally.
3. On the HR41-2805:
Make external connections to both output common pins (8 and 9).
Make external connections to both positive output pins (12 and 13).
MODEL NUMBERING KEY
Base Model
Input Voltage
MSR
28 512 T / ES
Output Voltage
(Main and aux. Vout for triple models)
Number of Outputs
(S = single, D = dual, T = triple)
Screening
(Standard screening has no designator
in this position.)
B4-30
24021-001-DTS Rev A
DQ# 1022
All technical information is believed to be accurate, but no responsibility is
assumed for errors or omissions. Interpoint reserves the right to make changes in
products or specifications without notice. MSR Series is a trademark of Interpoint.
Copyright © 1992 - 1999 Interpoint. All rights reserved.
CASE C
Dot on top of case
indicates pin one
C
ASES
BOTTOM VIEW CASE C1
MSA Series: Screening – Standard, ES, or 883
SMSA Series: Screening – Space Standard, H, or K
Seam Seal
Projection Weld
0.932
(23.67)
0.025
(0.64)
dia.
CASE C
BOTTOM VIEW
See Figures 9 - 11
for pin configurations.
Squared corner and dot on
top of case indicate pin one.
1
2
3
4
5
1.075 max
(27.31)
1.075 max
(27.31)
Materials
Header Case C1
Cold Rolled Steel/Nickel/Gold
Cases C2 and C3
Kovar/Nickel/Tin
Cover Case C1
Cold Rolled Steel/Nickel
Cases C2 and C3
Kovar/Nickel/Tin
Pins
Case C1
Copper/Nickel/Gold
Cases C2 and C3
Kovar/Nickel/Gold,
matched glass seal
Case dimensions in inches (mm)
Tolerance
±0.005
(0.13) for three decimal places
±0.01
(0.3) for two decimal places
unless otherwise specified
CAUTION
Heat from reflow or wave soldering may
damage the device. Solder pins
individually with heat application not
exceeding 300°C for 10 seconds per
pin.
0.205
±0.010
(5.21
±0.25)
0.270 max.
(6.86)
0.000
0.205
±0.010
(5.21
±0.25)
0.270 max.
(6.86)
0.000
0.132
(3.35)
0.000
0.000
8
7
6
0.132 (3.35)
0.332 (8.43)
0.532 (13.51)
0.732 (18.59)
F
IGURE
9:
C
ASE
C1
BOTTOM VIEW CASE C2
MSR Series: Screening – Standard or ES
HR40 Series: No screening options
0.018
±0.002
dia.
(0.46
±0.05)
Dot on top of case
indicates pin one
1 2
0.800 (20.32
9
18 17
0.932 (23.67)
10
3 4
6 5
0.205
±0.010
(5.21
±0.25)
0.370 max.
(9.40)
0.350 (8.89)
Marker bead
on pin 18
0.100 (2.54)
Pins equally
spaced
0.800 (20.32)
F
IGURE
10:
C
ASE
C2
F
IGURE
8: C
ASE
C
M
AXIMUM
D
IMENSIONS
Seam Seal
BOTTOM VIEW CASE C3
MSF EMI Filter: Screening – Standard or ES
0.018
±0.002
dia.
(0.46
±0.05)
0.000
Dot on top of case
indicates pin one
1 2
0.800 (20.32
9 8
0.100 (2.54)
7
F
IGURE
11:
C
ASE
C3
B8-8
0.800 0.600
(20.32) (15.24)
Note: Although every effort has been
made to render the case drawings at
actual size, variations in the printing
process may cause some distortion.
Please refer to the numerical dimen-
sions for accuracy.
0.205
±0.010
(5.21
±0.25)
0.205
±0.010
(5.21
±0.25)
0.370 max.
(9.40)
0.350 (8.89)
0.365 max.
(9.27)
0.000
0.000
0.300
(7.62)
