F
EATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
Fully qualified to Class H or K
Radiation hardened
–55° to +125°C operation
16 to 40 VDC input
Fully Isolated
Magnetic feedback
MODELS
Fixed frequency, 600 kHz typical
VDC O
UTPUT
Topology – Single Ended Forward
SINGLE
DUAL
Inhibit function
3.3
±5
Sync function
5
±12
Indefinite short circuit protection
12
±15
15
Up to 30 watts output power
Trim function on single
Size (max.): Non-flanged Case: H2 2.125 x 1.125 x 0.400 inches (53.98 x 28.58 x 10.16 mm)
output models
Flanged Case: K3 2.910 x 1.125 x 0.400 inches (73.79 x 28.58 x 10.16 mm)
• Up to 81% efficiency
See Figures 22 through 25 for dimensions.
Weight:
Non-flanged 52 grams max., flanged 55 grams max.
Screening: Space prototype, Class H, or Class K (MIL-PRF-38534)
Radiation hardness levels O or R
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
SMTR SERIES
30 WATT
DESCRIPTION
The SMTR Series™ of 28 volt DC/DC converters offers up to
30 watts of output power from single or dual output configurations.
The operate over the full military temperature range of –55°C to
+125°C with up to 84% efficiency. SMTR converters are packaged
in hermetically sealed metal enclosures, making them ideal for use
in military, aerospace and other high reliability applications.
S
YNCHRONIZATION
Synchronizing the converter with the system clock allows the
designer to confine switching noise to clock transitions, minimizing
interference and reducing the need for filtering. In sync mode, the
converter will run at any frequency between 500 kHz and 675 kHz.
The sync control operates with a quasi-TTL signal at any duty cycle
between 40% and 60%. The sync pin should be connected to input
common pin when not in use.
S
CREENING AND
R
EPORTS
SMTR converters offer three screening options (Standard, Class H,
or Class K) and two levels of radiation hardness (O or R). See
Tables 1, 2, and 3 for more information. Detailed reports on product
performance are also available and are listed in Table 4.
W
IDE
V
OLTAGE
R
ANGE
SMTR converters are designed to provide full power operation over
a full 16 to 40 Vdc voltage range. Operation below 16 volts,
including MIL-STD-704D emergency power conditions is possible
with derated power.
C
ONVERTER
D
ESIGN
The SMTR converters are constant frequency, pulse-width mod-
ulated switching regulators which use a quasi-square wave, single
ended, forward converter design. Tight load regulation is maintained
by using a wide bandwidth magnetic feedback and, on single output
models, through use of remote sense. On dual output models, the
positive output is independently regulated and the negative output is
cross regulated through the use of tightly coupled magnetics.
Indefinite short circuit protection and overload protection are
provided by a constant current-limit feature. This protective system
senses current in the converter’s secondary stage and limits it to
approximately 115% of the maximum rated output current.
SMTR converters are provided with internal filtering capacitors that
help reduce the need for external components in normal operation.
For systems that require compliance with MIL-STD-461C’s CE03
standard, Interpoint offers filter/transient suppression modules
(including the FMC-461, FMD-461 and FM-704A series filters) which
will result in compliance.
I
MPROVED
D
YNAMIC
R
ESPONSE
The SMTR Series feed-forward compensation system provides
excellent dynamic response and noise rejection. Audio rejection is
typically 50 dB. The min. to max. step line transient response is typi-
cally less than 4%.
I
NHIBIT
F
UNCTION
SMTR converters provide an inhibit terminal that can be used to
disable internal switching, resulting in no output and very low
quiescent input current. The converter is inhibited when a TTL
compatible low (≤0.8V) is applied to the inhibit pin. The unit is
enabled when the pin, which is internally connected to a pull-up
resistor, is left unconnected or is connected to an open-collector
gate. The open circuit output voltage associated with the inhibit pin
is 9 to 11 Vdc. In the inhibit mode, a maximum of 8 mA must be sunk
from the inhibit pin.
21
SMTR SERIES
30 WATT
ABSOLUTE MAXIMUM RATINGS
Input Voltage
• 16 to 40 VDC
Output Power
• 25 to 30 watts depending on model
Lead Soldering Temperature (10 sec per pin)
• 300°C
Storage Temperature Range (Case)
• –65°C to +135°C
DC/DC C
ONVERTERS
SYNC AND INHIBIT
Sync (500 to 675 kHz)
• Duty cycle 40% min, 60% max
• Logic low 0.8 V max
• Logic high 4.5 V min, 5 V max
• Referenced to input common
• If not used, connect to input common
Inhibit TTL Open Collector
• Logic low (output disabled)
Voltage
≤0.8
V
Inhibit pin current 8.0 mA max
• Referenced to input common
• Logic high (output enabled)
Open collector
TYPICAL CHARACTERISTICS
Output Voltage Temperature Coefficient
• 100 ppm/°C typical single and dual outputs
• 200 ppm/°C main, 300 ppm/°C aux
triple output
Input to Output Capacitance
• 50 pF typ (100 pF typ triple outputs)
Current Limit
• 115% of full load typical
Isolation
• 100 megohm minimum at 500 V
Audio Rejection
• 40 dB typ (50 dB typ triple output)l
Conversion Frequency
• Free run 550 min, 600 typ, 650 max kHz
• External sync 500 to 675 kHz
Inhibit Pin Voltage (unit enabled)
• 9 to 11 V
RECOMMENDED OPERATING CONDITIONS
Input Voltage Range
• 16 to 40 VDC continuous
• 50 V for 50 msec transient
Case Operating Temperature (Tc)
• –55°C to +125°C full power
• –55°C to +135°C absolute
Derating Output Power/Current
• Linearly from 100% at 125°C to 0% at 135°C
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, radiation level O, unless otherwise specified.
SINGLE OUTPUT MODELS
PARAMETER
OUTPUT VOLTAGE
OUTPUT CURRENT
1
OUTPUT POWER
1
OUTPUT RIPPLE
VOLTAGE
LINE REGULATION
2
LOAD REGULATION
INPUT VOLTAGE
1
NO LOAD TO FULL
INPUT CURRENT
1
CONDITION
V
IN
= 16 to 40 VDC
V
IN
= 16 to 40 VDC
10 kHz – 2 MHz
Tc = –55°C TO +125°C
Vin = 16 to 40 VDC
Tc = –55°C TO +125°C
NO LOAD TO FULL
Tc = –55°C TO +125°C
CONTINUOUS
TRANSIENT 50 ms
NO LOAD
FULL LOAD
INHIBITED
10 kHz – 10 MHz
Tc = –55°C TO +125°C
SHORT CIRCUIT
POWER DISSIPATION
RECOVERY
1, 4
50% – 100% – 50%
TRANSIENT
RECOVERY
4
16 – 40 – 16 VDC
TRANSIENT
5
RECOVERY
4
DELAY
OVERSHOOT
FULL LOAD
NO LOAD
SMTR283R3S
MIN
3.27
0
0
—
—
—
—
16
—
—
—
—
—
74
—
—
—
—
—
—
—
—
—
TYP
3.30
––
—
15
—
—
—
28
—
30
0.94
7
25
76
—
1.4
MAX
3.33
5.45
18
40
50
20
20
40
50
75
—
8
50
—
10
6
SMTR2805S
MIN
4.95
0
0
—
—
—
—
16
—
—
—
—
—
74
—
—
—
—
—
—
—
—
—
TYP
5.00
—
—
35
50
15
15
28
—
35
1.15
3
20
78
—
1.4
SMTR2812S
SMTR2815S
UNITS
VDC
A
W
mV p-p
MAX MIN TYP MAX MIN TYP MAX
5.05 11.88 12.00 12.12 14.85 15.00 15.15
5.0
0
—
2.5
0
—
2.0
25
40
90
50
50
40
50
75
—
8
50
—
10
5
0
—
—
—
—
16
—
—
—
—
—
78
—
—
—
—
—
—
—
—
—
—
25
40
15
15
28
—
35
1.30
3
20
83
—
1.4
30
40
90
50
50
40
50
75
—
8
50
—
10
5
0
—
—
—
—
16
—
—
—
—
—
79
—
—
—
—
—
—
—
—
—
—
25
40
15
15
28
—
35
1.25
3
20
84
—
1.4
30
40
90
50
50
40
50
75
—
8
50
—
10
5
mV
mV
VDC
V
mA
A
mA
mA p-p
%
W
ms
mV pk
µs
mV pk
µs
ms
INPUT RIPPLE
CURRENT
EFFICIENCY
LOAD FAULT
3
STEP LOAD RESP.
±125 ±250
—
200
—
—
1.4
0
33
±300
300
5
50
150
±200 ±300
60
200
±200 ±300
—
300
1.4
0
50
5
50
250
±250 ±400
60
200
±400 ±500
—
300
1.4
0
120
5
120
600
±350 ±500
60
200
±500 ±600
—
300
1.4
0
150
5
150
750
STEP LINE RESP.
START-UP
1
mV pk
Notes
1. Tc = –55°C to +125°C
2. Operation is limited below 16V (see Figure 21).
3. Indefinite short circuit protection not guaranteed above 125°C case.
4. Recovery time is measured from application of the transient to point at which
Vout is within 1% of final value.
5. Transition time
≥10
µs.
22
DC/DC C
ONVERTERS
DUAL OUTPUT MODELS
PARAMETER
OUTPUT VOLTAGE
CONDITIONS
+V
OUT
–V
OUT
OUTPUT CURRENT
1, 2
OUTPUT POWER
1, 2
OUTPUT RIPPLE
VOLTAGE +/– V
OUT
LINE REGULATION
3
V
IN
= 16 TO 40 VDC
LOAD REGULATION
NO LOAD TO FULL
CROSS REGULATION
EFFECT ON –V
OUT
INPUT VOLTAGE
1
NO LOAD TO FULL
INPUT CURRENT
V
IN
= 16 TO 40 VDC
V
IN
= 16 TO 40 VDC
10 kHz - 2 MHz
Tc = –55°C TO +125°C
Tc = –55°C
TO +125°C
Tc = –55°C
TO +125°C
SEE NOTE 4
SEE NOTE 5
CONTINUOUS
TRANSIENT 50 ms
NO LOAD
FULL LOAD
INHIBITED
10 kHz - 10 MHz
POWER DISSIPATION
SHORT CIRCUIT
1
RECOVERY
50 – 100 – 50% BALANCED
TRANSIENT
RECOVERY
7
16 – 40 – 16 V
IN
TRANSIENT
8
RECOVERY
7
START–UP
1
DELAY
OVERSHOOT
FULL LOAD
NO LOAD
—
—
0
50
180
250
—
—
0
120
120
600
—
—
0
150
+V
OUT
–V
OUT
+V
OUT
–V
OUT
SMTR2805D
MIN
TYP
MAX
4.95
5.00
5.05
4.92
0
0
—
—
—
—
—
—
—
—
16
0
—
—
—
—
74
—
—
—
—
—
—
—
5.00
2.5
—
20
40
10
50
5
25
7
4
28
—
35
1.10
3
15
76
—
1.4
±200
100
±200
—
1.4
5.08
4.5
25
50
80
50
100
50
100
12
6
40
50
75
—
8
50
—
10
5.0
±300
200
±400
300
5
SMTR2812D
MIN
TYP
MAX
11.88 12.00 12.12
11.82
0
0
—
—
—
—
—
—
—
—
16
0
—
—
—
—
77
—
—
—
—
—
—
—
12.00
1.25
—
30
40
10
50
15
30
4
4
28
—
50
1.34
3
20
80
—
1.4
±150
100
±200
—
1.4
12.18
2.25
30
80
120
50
150
50
180
8.3
6
40
50
75
—
8
50
—
10
5.0
±300
200
±400
300
5
SMTR SERIES
30 WATT
SMTR2815D
MIN
TYP
MAX
14.85 15.00 15.15
14.77 15.00
0
0
—
—
—
—
—
—
—
—
16
0
—
—
—
—
78
—
—
—
—
—
—
—
1.0
—
25
40
10
50
15
30
3
4
28
—
50
1.29
3
20
81
—
1.4
±200
100
±400
—
1.4
15.23
1.8
30
80
120
50
180
50
180
8
6
40
50
75
—
8
50
—
10
5.0
±400
200
±500
300
5
150
750
A
W
mV p-p
UNITS
VDC
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, radiation level O, unless otherwise specified.
mV
mV
%
VDC
V
mA
A
mA
mA p-p
%
W
ms
mV pk
µs
mV pk
µs
ms
INPUT RIPPLE
CURRENT
1
EFFICIENCY
LOAD FAULT
6
STEP LOAD
RESPONSE ± V
OUT
STEP LINE
RESPONSE ± V
OUT
mV pk
Notes
1. Tc = –55°C to +125°C.
2. Up to 90% of the total output current/power is available from either output
providing the positive output is carrying at least 10% of the total output
power.
3. Operation is limited below 16 V (see Figure 21).
4. Effect on the negative output under the following conditions:
+P
out
20% to 80%; –P
out
80% to 20%
5. Effect on the negative output under the following conditions:
+P
out
50%; –P
out
10% to 50%
6. Indefinite short circuit protection not guaranteed above 125°C case.
7. Recovery time is measured from application of the transient to point at which
Vout is within 1% of final value.
8. Transition time
≥
10 µs.
23
SMTR SERIES
30 WATT
1
+VIN
OUTPUT
COMMON
SENSE
RETURN
SENSE
INPUT
COMMON
POSITIVE
OUTPUT
DC/DC C
ONVERTERS
TRIM AND REMOTE SENSE (AVAILABLE ON SINGLE OUTPUT MODELS ONLY)
SMTR SINGLE OUTPUT CONVERTER
1
1
3
6
1
RT
5
10
RL
SENSE
INPUT
COMMON
POSITIVE
OUTPUT
+VIN
OUTPUT
COMMON
SENSE
RETURN
4
2
3
6
2
RL
4
SMTR SINGLE OUTPUT CONVERTER
10
5
EXTERNAL TRIM CONNECTION
1 Make connections at converter.
REMOTE SENSE CONNECTION
2 Make connections at load.
F
IGURE
1: T
RIM
C
ONNECTION1, 2, 3
Trim Formulas
Vout = desired output voltage; Rt = trim resistor
5V: Rt = 1300*Vout – 6512
1.2475
12V: Rt = 1300*Vout – 15631
1.2475
15V: Rt = 1300*Vout – 19498
1.2475
F
IGURE
2: R
EMOTE
S
ENSE2, 3
Notes for Remote Sense and Trim
1. When trimming output voltage and/or remote sensing, the total output
voltage increase must be less than 0.6 volts at the converters pins to
maintain specified performance.
2. If neither voltage trim nor remote sense will be used, connect pin 3 to
pin 4 and pin 5 to pin 6 or the output voltage will increase by 1.2 volts.
3. CAUTION: The converter will be permanently damaged if the positive
remote sense (pin 6) is shorted to ground. Damage may also result if
the output common or positive output is disconnected from the load with
the remote sense leads connected to the load.
PIN OUT
Dot on top of cover indicates pin one.
Pin
1
2
3
4
5
6
7
8
9
10
Single Output
Positive Input
Inhibit
Sense Return
Output Common
Positive Output
Positive Sense
Case Ground
Case Ground
Sync
Input Common
Dual Output
Positive Input
Inhibit
Positive Output
Output Common
Negative Output
Case Ground
Case Ground
Case Ground
Sync
Input Common
1
2
3
4
5
BOTTOM VIEW
SMTR SINGLE
FLANGED AND NON-FLANGED
10
9
8
7
6
Dotted line outlines flanged package option.
See Figures 22 and 23 and for dimensions.
F
IGURE
3: P
IN
O
UT
S
INGLE
O
UTPUT
M
ODELS
Dot on top of cover indicates pin one.
1
2
3
4
5
BOTTOM VIEW
SMTR DUAL
FLANGED AND NON-FLANGED
10
9
8
7
6
Dotted line outlines flanged package option.
See Figures 24 and 25 for dimensions.
F
IGURE
4: P
IN
O
UT
D
UAL
O
UTPUT
M
ODELS
24
DC/DC C
ONVERTERS
SMD NUMBERS
S
TANDARD
M
ICROCIRCUIT
D
RAWING
(SMD)
5962-0150102HXC
5962-9306802HXC
5962-9306902HXC
5962-9307002HXC
IN PROCESS
IN PROCESS
IN PROCESS
MTR S
ERIES
S
IMILAR
P
ART
SMTR283R3S/HO
SMTR2805S/HO
SMTR2812S/HO
SMTR2815S/HO
SMTR2805D/HO
SMTR2812D/HO
SMTR2815D/HO
SMTR SERIES
30 WATT
MODEL NUMBERING KEY
Base Model
Input Voltage
Output Voltage
Number of Outputs
(S = single, D = dual)
Case Option
(Non-flanged case has no designator
in this position)
Screening
Radiation Level
SMTR
28 05 S F / K
R
To indicate the flanged case option change the “X” to “Z” In the
SMD number. The SMD number shown is for Class H
screening, non-flanged, and no Radiation Hardness Assurance
(RHA) level. See the SMD for the numbers for other screening
and radiation levels. For exact specifications for an SMD
product, refer to the SMD drawing. Call your Interpoint repre-
sentative for status on the SMHF SMD releases which are “in
process.” SMDs can be downloaded from
http://www.dscccols.com//programs/smcr
Typical Performance Curves: 25°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
85
16V
80
80
85
16V
82
87
16V
28V
EFFICIENCY (%)
EFFICIENCY (%)
EFFICIENCY (%)
28V
75
28V
75
40V
70
77
40V
72
70
40V
65
65
67
60
5
10
15
20
25
60
62
5
10
15
20
5
10
15
20
25
OUTPUT POWER (Watts)
OUTPUT POWER (Watts)
OUTPUT POWER (Watts)
SMTR2805S EFFICIENCY
SMTR2812S EFFICIENCY
SMTR2815S EFFICIENCY
F
IGURE
5
85
16V
80
28V
85
16V
90
F
IGURE
6
F
IGURE
7
0
10
EFFICIENCY (%)
EFFICIENCY (%)
ATTENUATION (dB)
20
28V
80
20
30
40
50
60
70
80
90
75
70
40V
65
75
40V
70
60
5
10
15
20
65
5
10
15
OUTPUT POWER (Watts)
100
0.1
1
10
100
SMTR2812D EFFICIENCY
OUTPUT POWER (Watts)
FREQUENCY (kHz)
SMTR2815D EFFICIENCY
AUDIO REJECTION, SMTR SERIES
F
IGURE
8
F
IGURE
9
F
IGURE
10
25