F
EATURES
• –55°C to +85°C operation
• 10 to 16 VDC input or
16 to 36 VDC input typical
• Fully isolated
• Opto-coupler feedback
• Fixed frequency 125 kHz typical
• Topology – Push-Pull Forward
• Transient protection
50 V for up to 50 ms 28 Vin models
• Inhibit function
• Indefinite short circuit protection
• Trimmable output on single models
• Up to 83% efficiency
DC/DC C
ONVERTERS
12
AND
28 V
OLT
I
NPUT
MHE/MLP SERIES
20 WATT
MODELS
VDC O
UTPUT
SINGLE
DUAL
5
±12
12
±15
15
Size (max.): Non-flanged 2.125 x 1.125 x 0.495 MHE (case H6) inches
or 0.417 MLP (case H4)
(53.98 x 28.58 x 12.57 (MHE) or 10.59 (MLP) mm)
Flanged 2.910 x 1.125 x 0.495 MHE (case K7) inches
or 0.417 MLP (case K5)
(73.91 x 28.58 x 12.57 (MHE) or 10.59 (MLP) mm)
See Section B8, cases H4, H6, K5, and K7, for dimensions.
Weight:
50 grams typical
Screening: Standard or ES. See Section C2 for screening options, see
Section A5 for ordering information.
DESCRIPTION
The MHE Series™ and the MLP Series™ DC/DC converters offer
the high efficiencies associated with switching regulators, yet have
full isolation and the excellent regulation typical of linear regulators.
No external components are required for operation. MHE Series and
MLP Series converters are built using thick-film hybrid technology,
and are sealed in metal packages for military, aerospace, and other
high-reliability applications. Unscreened models are solder sealed
and are guaranteed to pass a gross leak test (maximum leak rate of
1 x 10
-3
atm.-cc/sec). Environmentally screened models are
hermetically sealed and are screened as described in Section C2.
The MHE Series and MLP Series converters are pulse-width modu-
lated switching regulators operating in the forward mode, with a
nominal switching frequency of 125 to 140 kHz. Isolation is achieved
through the use of a transformer in the forward power circuit, and an
optocoupler is used in the feedback/control loop. The full load output
power is available over the full input voltage range. Short-term tran-
sients of 50 volts will not impair normal operation for 28 volt input
models.
The efficiency is typically greater than 80% over the entire input
voltage range and from approximately 25% of full load to full load.
This feature makes the MHE/MLP Series converters ideal for either
battery or aircraft power applications.
An inhibit function is provided on MHE/MLP Series converters to
allow power shutdown and startup from a logic input. The unit is
inhibited when the inhibit input pin (pin 2) is connected to the input
common (pin 10). The open circuit voltage of the inhibit pin is 8 to
10 VDC for 12 V input models or 11 to 13 VDC for 28 V input
models. During inhibit, the input inhibit pin must sink approximately
1 mA. In the inhibit mode, converter output drops to less than 1 V
and the input current is typically 8 mA.
Automatic current limiting circuitry protects the MHE/MLP Series
converters against short circuits.
MHE/MLP Series converters are rated to operate at full load up to a
case temperature of 85°C, with the output power derated linearly to
zero at 115°C. Because of the unit’s high efficiency, heat sinking
requirements are minimized, but due consideration should be given
to removing self-generated heat when operating the device at
maximum ratings. To increase dissipation, heat conducting material
(PCB, copper sheet, heat sink, etc.) should be brought into contact
with the converter’s baseplate.
When the MHE/MLP Series converters are used in applications
requiring full power operation for extended periods of time, or in
shock and vibration environments, it is highly recommended that the
flange-mount option be used. This option provides improved thermal
transfer capabilities as well as a mechanically secure mounting
configuration.
B4-13
MHE/MLP SERIES
20 WATT
ABSOLUTE MAXIMUM RATINGS
Output Power
• 10 to 20 watts depending on model
Lead Soldering Temperature (10 sec per lead)
• 300°C
Storage Temperature Range (Case)
• –55°C to +125°C
DC/DC C
ONVERTERS
INHIBIT
Inhibit TTL Open Collector
• Logic low (output disabled)
Logic low voltage
≤0.8
V
• Referenced to input common
• Logic high (output enabled)
Open collector
TYPICAL CHARACTERISTICS
Output Voltage Temperature Coefficient
• 150 ppm/°C, typical
Input to Output Capacitance
• 60 pF, typical
Current Limit
• 125% of full load, typical
Isolation
• 100 megohm minimum at 500 V
Conversion Frequency
• 125 kHz, typical
Inhibit Pin Voltage (unit enabled)
• 11 to 13 V MHE28XXX, MLP28XXX
• 8 to 10 V MHE12XXX
RECOMMENDED OPERATING CONDITIONS
Input Voltage Range
Continuous
• 17 to 40 VDC MHE28XXX
• 10 to 16 VDC MHE12XXX
• 16 to 40 VDC MLP28XXX
Transient
• 50 V for 50 msec on 28 V input models
Case Operating Temperature (Tc)
• –55°C to +85°C full power
Derating Output Power/Current
• Linearly from 100% at 85°C to 0% at 115° C
• MHE28XXX models derate by 33% at 16 Vin
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, unless otherwise specified.
SINGLE OUTPUT MHE12XX MODELS
PARAMETER
OUTPUT VOLTAGE
OUTPUT CURRENT
OUTPUT POWER
OUTPUT RIPPLE
VOLTAGE
LINE REGULATION
LOAD REGULATION
INPUT VOLTAGE
INPUT CURRENT
INPUT RIPPLE
CURRENT
EFFICIENCY
CONDITION
–55°C TO +85°C
–55°C TO +85°C
0 TO 1 MHz
V
IN
MIN TO MAX
NO LOAD TO FULL
CONTINUOUS
TRANSIENT 50 ms
NO LOAD
10 kHz – 2 MHz
MIN
4.95
—
—
—
—
—
10
—
—
—
78
MHE1205S
TYP
5.00
—
—
35
2
10
12
—
—
30
81
MAX
5.05
3
15
70
5
20
16
—
24
80
—
MIN
11.88
—
—
—
—
—
10
—
—
—
79
MHE1212S
TYP
12.00
—
—
35
3
5
12
—
—
30
82
MAX
12.12
1.25
15
70
10
15
16
—
32
80
—
MHE1215S
MIN
14.85
—
—
—
—
—
10
—
—
—
80
TYP
15.00
—
—
35
3
10
12
—
—
30
83
MAX UNITS
15.15 VDC
1.0
A
15
70
10
20
16
—
32
80
—
W
mV p-p
mV
mV
VDC
V
mA
mA p-p
%
B4-14
DC/DC C
ONVERTERS
SINGLE AND DUAL MHE28XX MODELS
PARAMETER
CONDITIONS
OUTPUT VOLTAGE
OUTPUT CURRENT
1
–55 TO +85°C
OUTPUT POWER
1
OUTPUT RIPPLE
VOLTAGE
LINE REGULATION
LOAD REGULATION
INPUT VOLTAGE
INPUT CURRENT
INPUT RIPPLE
CURRENT
EFFICIENCY
–55 TO +85°C
0 - 1 MHz
V
IN
MIN TO MAX
NO LOAD TO FULL
CONTINUOUS
TRANSIENT 50 ms
NO LOAD
10 kHz - 2 MHz
MHE/MLP SERIES
20 WATT
UNITS
VDC
A
W
mV p-p
mV
mV
VDC
V
mA
mA p-p
%
Electrical Characteristics: 25°C Tc, 28 VDC Vin (12 Vin for 12 V models), 100% load, unless otherwise specified.
MHE2805S
MHE2812S
MHE2815S
MHE2812D
MHE2815D
MIN TYP MAX MIN TYP MAX MIN TYP MAX
MIN
TYP MAX
MIN
TYP MAX
4.95 5.00 5.05 11.88 12.00 12.12 14.85 15.00 15.15 ±11.88 ±12.00 ±12.12 ±14.85 ±15.00 ±15.15
—
—
3.0
—
— 1.67
—
— 1.33
—
—
±0.63
—
—
±0.5
—
—
—
—
17
—
—
—
78
—
35
2
10
28
—
—
20
81
15
60
5
20
40
50
18
50
—
—
—
—
—
17
—
—
—
79
—
60
3
5
28
—
—
25
82
20
80
10
15
40
50
30
50
—
—
—
—
—
17
—
—
—
80
—
30
3
5
28
—
—
25
83
20
60
10
15
40
50
30
50
—
—
—
—
—
17
—
—
—
76
—
30
3
5
28
—
—
25
79
15
50
10
15
40
50
35
50
—
—
—
—
—
17
—
—
—
76
—
30
3
5
28
—
—
25
79
15
50
15
15
40
50
35
50
—
SINGLE AND DUAL MLP MODELS
PARAMETER
CONDITIONS
OUTPUT VOLTAGE
OUTPUT CURRENT
1
–55 TO +85°C
OUTPUT POWER
1
OUTPUT RIPPLE
VOLTAGE
LINE REGULATION
–55 TO +85°C
0 - 1 MHz
V
IN
MIN TO MAX
MLP2805S
MLP2812S
MLP2815S
MLP2812D
MLP2815D
MIN TYP MAX MIN TYP MAX MIN TYP MAX
MIN
TYP MAX
MIN
TYP MAX
4.95 5.00 5.05 11.88 12.00 12.12 14.85 15.00 15.15 ±11.88 ±12.00 ±12.12 ±14.85 ±15.00 ±15.15
—
—
2
—
— 1.25
—
—
1
—
—
±0.41
—
— ±0.33
—
—
—
—
16
—
—
—
78
—
25
2
10
28
—
—
20
81
10
60
5
20
40
50
20
50
—
—
—
—
—
16
—
—
—
79
—
30
3
5
28
—
—
25
82
15
50
10
15
40
50
30
50
—
—
—
—
—
16
—
—
—
80
—
30
3
5
28
—
—
25
83
15
50
10
15
40
50
30
50
—
—
—
—
—
16
—
—
—
78
—
30
3
5
28
—
—
25
81
10
60
10
15
40
50
30
50
—
—
—
—
—
16
—
—
—
78
—
30
3
5
28
—
—
25
81
10
60
10
15
40
50
30
50
—
UNITS
VDC
A
W
mV p-p
mV
mV
VDC
V
mA
mA p-p
%
LOAD REGULATION NO LOAD TO FULL
INPUT VOLTAGE
CONTINUOUS
TRANSIENT 50 ms
INPUT CURRENT
NO LOAD
INPUT RIPPLE
CURRENT
10 kHz - 2 MHz
EFFICIENCY
Note
1. On dual output models at least 25% of the load should be on the positive output.
B4-15
MHE/MLP SERIES
20 WATT
Pin
1
2
3
4
5
6
7
8
9
10
Single Output
Positive Input
Inhibit
Output Adjust
Output Common
Positive Output
No connection
No connection
Case Ground
No connection
Input Common
DC/DC C
ONVERTERS
PIN OUT
Dual Output
Positive Input
Inhibit
Positive Output
Output Common
Negative Output
No connection
No connection
Case Ground
No connection
Input Common
Squared corner and dot on
top of cover indicate pin one.
1
2
3
4
5
BOTTOM VIEW
MHE and MLP
10
9
8
7
6
Dotted line outlines flanged package option.
See Section B8, case H4, H6, K5 and K7 for dimensions.
F
IGURE
1: P
IN
O
UT
MODEL NUMBERING KEY
MHE
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
(Standard screening has no designator
in this position.)
28 12 S
F / ES
OUTPUT ADJUSTMENT RESISTOR VALUES
FOR MHE2805S AND MLP2805S
TYPICAL PERFORMANCE CURVE
Resistance
Pin 3 to 4
Output Voltage
Increase (%)
0
+1%
+2%
+3%
+4%
+5%
86
18 V
84
82
28 V
∞
390K
145K
63K
22K
0
Efficiency (%)
80
78
76
74
72
2.5
5.0
7.5
10.0
12.5
15.0
36 V
Output Adjustment all single output models:
The output can be adjusted upward by using the output
adjust (pin3). The resistance between output adjust (pin 3)
and output common (pin 4) will determine the magnitude of
the increase in the output.
The table above is applicable
only to MHE2805S and MLP2805S.
Output Power (Watts)
MLP2815S Efficiency
F
IGURE
2
B4-16
22820-001-DTS Rev
B
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 spec-
ifications without notice. MHE Series and MLP Series are trademarks of Interpoint.
Copyright © 1995 - 1999 Interpoint. All rights reserved.
C
ASES
Dot on top of case indicates pin one
CASE H
CASE H
BOTTOM VIEW
See Figures 29 – 34
for pin configurations.
1.125 max
(28.58)
2.125 max
(53.98)
Materials
Header Cold Rolled Steel/Nickel/Gold
cases H1 and H2
Cold Rolled Steel/Nickel/Tin
cases H3, H4, and H5
Cover Kovar/Nickel
cases H1 and H2
Cold Rolled Steel/Nickel/Tin
cases H3, H4, and H5
Pins
#52 alloy
ceramic seal
case H1
case H2 (except MHV Series Single and Dual)
compression glass seal
MHV Series Single and Dual
case H3, H4, H5
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.
F
IGURE
28: C
ASE
H M
AXIMUM
D
IMENSIONS
BOTTOM VIEW CASE H1
FMC EMI Filter: Screening – Standard, ES, or 883
SFMC EMI Filter: Screening – Space Standard, H, or K
Seam Seal
0.040 dia
(1.02)
1.110 (28.19)
0.955 (24.26)
1
0.555 (14.1)
5
0.155 (3.94)
0.000
0.400 max.
(10.16)
0.000
0.25
±0.03
(6.4
±0.8)
0.000
0.245
(6.22)
1.845
(46.86)
2.090
(53.01)
4
2
3
Squared corner and dot on top
of case indicate pin one.
F
IGURE
29: C
ASE
H1
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 dimensions for accuracy.
B8-17