1
Size (max.): Non flanged 1.460 x 1.130 x 0.330 (37.08 x 28.70 x 8.38 mm)
Flanged 2.005 x 1.130 x 0.330 (50.93 x 28.70 x 8.38 mm)
Weight: 30 grams maximum.
Screening: Standard, ES, or 883 (Class H).
DESCRIPTION
The MHF+ Series™ of high frequency DC/DC converters offers a
wide input voltage range of 16 to 40 volts and up to 15 watts of
output power. The units are capable of withstanding short term tran-
sients up to 50 volts. The package is a hermetically sealed, welded
metal case. Flanged and non-flanged models are available.
CONVERTER DESIGN
The MHF+ converters are switching regulators that use a quasi-
square wave, single-ended forward converter design with a constant
switching frequency of 550 kHz. Isolation between input and output
circuits is provided with a transformer in the forward path and a
temperature compensated optical link in the feedback control loop.
For the MHF+ dual output models, good cross regulation is main-
tained by tightly coupled output magnetics. Up to 90% of the total
output power (80% on 2805D) is available from either output,
providing the opposite output is simultaneously carrying 10% of the
total output power (20% on 2805D models). Predictable current limit
is accomplished by directly monitoring the output load current and
providing a constant current output above the overload point.
HIGHER POWER DENSITY
The MHF+ Series offers a new standard of performance for small
size and high power density. At just 0.33 inch high and a total foot-
print of 1.7 in2, this low profile package offers a total power density
of up to 28 watts per cubic inch.
LOW NOISE,HIGH AUDIO REJECTION
The MHF+ converters’ feed-forward compensation system provides
excellent dynamic response and noise rejection. Audio rejection is
typically 50 dB. Typical output voltage response for a 50% to 100%
step load transient is as low as 1.3% with a 150 msec recovery time.
Input ripple current is typically 35 mA p-p with output ripple voltage
typically 30 mV p-p .
INHIBIT FUNCTION
MHF+ converters provide an inhibit terminal that can be used to
disable internal switching, resulting in no output and very low quies-
cent input current. The converter is inhibited when a TTL compatible
low (≤0.8 – output disabled) 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 8.5 to 12 V. In the inhibit mode, a maximum of 4 mA must be sunk
from the inhibit pin.
SYNCHRONIZATION
A synchronization feature is included with the MHF+ Series that
allows the user to match the switching frequency of the converter to
the frequency of the system clock. An external synchronization
feature is included that allows the user to adjust the nominally 550
kHz operating frequency to any frequency within the range of 500
kHz to 600 kHz. This is initiated by applying a TTL compatible input
of the desired frequency to pin 5.
SHORT CIRCUIT PROTECTION
MHF+ Series converters provide short circuit protection by
restricting the output current to approximately 115% of the full load
output current. The output current is sensed in the secondary stage
to provide highly predictable and accurate current limiting, and to
eliminate foldback characteristics.
UNDERVOLTAGE LOCKOUT
Undervoltage lockout prevents the units from operating below
approximately 12 VDC input voltage to keep system current levels
smooth, especially during initialization or re-start operations.
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
MHF+ SERIES
SINGLE & DUAL
15 WATT
FEATURES
• –55° to +125°C operation
• 16 to 40 VDC input
• Fully isolated
• Optocoupler feedback
• Fixed frequency, 550 kHz typical
• Topology – Single Ended Forward
• 50 V for up to 50 ms transient protection
• Inhibit and sync functions
• Indefinite short circuit protection
• Undervoltage lockout
• Up to 84% efficiency, 28 W/in3
MODELS
VDC OUTPUT
SINGLE
3.3
5
5.2
12
15
28
DUAL
±5
±12
±15
RECOMMENDED OPERATING CONDITIONS
TYPICAL CHARACTERISTICS
SYNC AND INHIBIT
ABSOLUTE MAXIMUM RATINGS
Input Voltage
• 16 to 40 VDC
Power Dissipation (Pd)
•6 W
Output Power
• 12 to 15 watts depending on model
Lead Soldering Temperature (10 sec per lead)
• 300°C
Storage Temperature Range (Case)
• –65°C to +150°C
2
DC/DC C
ONVERTERS
Output Voltage Temperature Coefficient
• 100 ppm/°C typical
• 150 ppm/°C maximum
Input to Output Capacitance
• 60 pF typical
Undervoltage Lockout
• 12 V input typical
Current Limit
• 115% of full load typical
Isolation
• 100 megohm minimum at 500 V
Audio Rejection
• 50 dB typical
Conversion Frequency (55°C to +125°C Tc)
• Free run 550 kHz typical
480 kHz min, 620 kHz max
Inhibit Pin Voltage (unit enabled)
• 8.5 to 12 V
Input Voltage Range
• 16 to 40 VDC continuous
• 50 V for up to 50 msec transient
Case Operating Temperature (Tc)
• –55°C to +125°C full power
• –55°C to +135°C absolute
Derating Output Power/Current (Tc)
• Linearly from 100% at 125°C to 0% at 135°C
MHF+ SERIES
SINGLE AND DUAL
15 WATT
SINGLE OUTPUT MODELS MHF+283R3S MHF+2805S MHF+285R2S
PARAMETER CONDITION MIN TYP MAX MIN TYP MAX MIN TYP MAX UNITS
OUTPUT VOLTAGE 3.27 3.30 3.33 4.95 5.00 5.05 5.16 5.20 5.24 VDC
OUTPUT CURRENT VIN = 16 to 40 VDC 0 — 2.4 0 — 2.4 0 — 2.4 A
OUTPUT POWER VIN = 16 to 40 VDC 0 — 8 0 — 12 0 — 12.48 W
OUTPUT RIPPLE 10 kHz - 2 MHz — 30 80 — 30 80 — 30 50 mV p-p
VOLTAGE Tc = –55°C to +125°C — 50 120 — 60 100 — 60 100
LINE REGULATION Vin = 16 to 40 VDC — 5 100 — 5 50 — 5 35 mV
LOAD REGULATION NO LOAD TO FULL — 20 50 — 20 50 — 20 35 mV
INPUT VOLTAGE CONTINUOUS 16 28 40 16 28 40 16 28 40 VDC
NO LOAD TO FULL TRANSIENT 50 ms — — 50 — — 50 — — 50 V
INPUT CURRENT NO LOAD — 25 65 — 25 40 — 25 42
FULL LOAD — — 397 — 560 624 — 560 605 mA
INHIBITED — 5 12 — 5 12 — 5 12
INPUT RIPPLE 10 kHz - 10 MHz — 45 80 — 35 80 — 35 100
CURRENT Tc = –55°C to +125°C — — 120 — — 100 — — 100 mA pp
EFFICIENCY 72 75 — 75 77 — 75 77 — %
LOAD FAULT1SHORT CIRCUIT
POWER DISSIPATION — 5 8 — 3.5 6 — 3.5 6 W
RECOVERY2— 7.5 30 — 7.5 30 — 7.5 30 ms
STEP LOAD RESP. 50% – 100% – 50%
TRANSIENT –400 150 500 –400 150 400 –400 150 400 mV pk
RECOVERY2— 150 300 — 150 300 — 150 300 µs
STEP LINE RESP. 16 – 40 – 16 VDC
TRANSIENT3–800 550 800 –800 550 800 –800 550 800 mV pk
RECOVERY2— 0.8 1.2 — 0.8 1.2 — 0.8 1.2 ms
START-UP DELAY — 10 25 — 10 25 — 10 25 ms
OVERSHOOT4— 200 300 — 100 600 — 100 600 mV pk
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
Notes
1. Indefinite short circuit protection not guaranteed above 125°C (case)
2. Recovery time is measured from application of the transient
to the point at which Vout is within regulation.
3. Input step transition time >10 µs.
4. Input step transition time <100 µs.
Sync In (500 to 600 kHz)
• Duty cycle 40% to 60%
• 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)
Logic low voltage ≤0.8 V
Inhibit pin current 4.0 mA max
• Referenced to input common
• Logic high (output enabled)
Open collector or unconnected
3
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
SINGLE OUTPUT MODELS MHF+2812S MHF+2815S MHF+2828S
PARAMETER CONDITION MIN TYP MAX MIN TYP MAX MIN TYP MAX UNITS
OUTPUT VOLTAGE 11.88 12.00 12.12 14.85 15.00 15.15 27.72 28.00 28.28 VDC
OUTPUT CURRENT VIN = 16 to 40 VDC 0 — 1.25 0 — 1.00 0 — 0.54 A
OUTPUT POWER VIN = 16 to 40 VDC 0 — 15 0 — 15 0 — 15 W
OUTPUT RIPPLE 10 kHz - 2 MHz — 30 80 — 30 80 — 60 120 mV p-p
VOLTAGE Tc = –55°C to +125°C — 50 120 — 50 120 — 100 180
LINE REGULATION Vin = 16 to 40 VDC — 5 50 — 5 50 — 50 150 mV
LOAD REGULATION NO LOAD TO FULL — 20 50 — 20 50 — 50 150 mV
INPUT VOLTAGE CONTINUOUS 16 28 40 16 28 40 16 28 40 VDC
NO LOAD TO FULL TRANSIENT 50 ms — — 50 — — 50 — — 50 V
INPUT CURRENT NO LOAD — 25 50 — 25 62 — 25 60
FULL LOAD — 680 752 — 670 752 — 640 760 mA
INHIBITED — 5 12 — 5 12 — 5 12
INPUT RIPPLE 10 kHz - 10 MHz — 35 80 — 35 80 — 35 80
CURRENT Tc = –55°C to +125°C — — 120 — — 120 — — 120 mA pp
EFFICIENCY 78 79 — 78 80 — 82 84 — %
LOAD FAULT1SHORT CIRCUIT
POWER DISSIPATION — 3.5 6 — 3.5 6 — 3.5 6 W
RECOVERY2— 7.5 30 — 7.5 30 — 7.5 30 ms
STEP LOAD RESP. 50% – 100% – 50%
TRANSIENT –500 150 500 –600 200 600 –800 600 800 mV pk
RECOVERY2— 150 300 — 150 300 — 200 400 µs
STEP LINE RESP. 16 – 40 – 40 VDC
TRANSIENT3–800 550 800 –800 550 800 –1200 1100 1200 mV pk
RECOVERY2— 0.8 1.2 — 0.8 1.2 — 0.8 1.2 ms
START-UP DELAY 0 10 25 0 10 25 0 10 25 ms
OVERSHOOT40 200 1200 0 200 1500 0 200 280 mV pk
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
Notes
1. Indefinite short circuit protection not guaranteed above 125°C (case)
2. Recovery time is measured from application of the transient to point at
which Vout is within regulation.
3. Input step transition time >10 µs.
4. Input step transition time <100 µs.
4
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
DUAL OUTPUT MODELS MHF+2805D MHF+2812D MHF+2815D
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX MIN TYP MAX UNITS
OUTPUT VOLTAGE +VOUT 4.95 5.00 5.05 11.88 12.00 12.12 14.85 15.00 15.15 VDC
–VOUT 4.92 5.00 5.08 11.82 12.00 1218 14.78 15.00 15.23
OUTPUT CURRENT1VIN = 16 to 40 VDC — ±1.2 1.92 — ±0.625 1.125 — ±0.500 0.900 A
OUTPUT POWER1VIN = 16 to 40 VDC — — 12 — — 15 — — 15 W
OUTPUT RIPPLE 10 kHz - 2 MHz — 30 80 — 30 80 — 30 80
VOLTAGE ±VOUT Tc = –55°C to +125°C — 60 120 — 60 120 — 50 120 mV p-p
LINE REGULATION BALANCED +VOUT — 5 50 — 5 50 — 5 50 mV
Vin = 16 to 40 VDC LOAD –VOUT — — 80 — — 100 — — 100
LOAD REGULATION BALANCED +VOUT — 20 50 — 20 50 — 20 50 mV
LOAD –VOUT — — 100 — — 100 — — 100
CROSS REGULATION2NEGATIVE VOUT — 6 7.5 — 3 6 — 3 6 %
INPUT VOLTAGE CONTINUOUS 16 28 40 16 28 40 16 28 40 VDC
NO LOAD TO FULL TRANSIENT 50 msec — — 50 — — 50 — — 50 V
INPUT CURRENT NO LOAD — 20 40 — 25 50 — 25 50
FULL LOAD — 540 600 — 645 754 — 638 754 mA
INHIBITED — 6 12 — 5 12 — 5 12
INPUT RIPPLE 10 kHz - 10 MHz — 20 50 — 35 60 — 35 60
CURRENT Tc = –55°C to +125°C — 40 80 — 50 100 — 50 100 mA p-p
EFFICIENCY 77 79 — 76 83 — 76 84 — %
LOAD FAULT SHORT CIRCUIT3
POWER DISSIPATION — 3 6 — 3 6 — 3 6 W
RECOVERY4— 7.5 30 — 7.5 50 — 7.5 50 ms
STEP LOAD RESP.550% – 100% – 50%
BALANCED LOADS TRANSIENT +VOUT –600 200 600 –600 300 600 –600 300 600 mV pk
–VOUT –600 150 600 –600 100 500 –600 100 600
RECOVERY4— 150 500 — 200 400 — 200 500 µs
STEP LINE RESP. 16 – 40 – 40 VDC
±V
OUT TRANSIENT6–800 600 800 –750 550 750 –750 550 750 mV pk
RECOVERY4— 0.8 1.2 — 0.8 1.2 — 0.8 1.2 ms
START-UP DELAY — 12 20 — 12 25 — 12 25 ms
OVERSHOOT70 100 250 0 200 750 0 200 750 mV pk
Notes
1. Up to 13.5 watts, 90% (9.6W, 80% for 2805D) of the total output power is
available from either output providing the opposite output is simultaneously
carrying 10% (20% for 2805D) of the total output power. Each
output must carry a minimum of 10% (20% for 2805D) of the total output
power in order to maintain regulation on the negative output.
2. Effect on –Vout for the following conditions:
+Po = 50% to 10% and –Po = 50%
+Po = 50% and –Po = 50% to 10%
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 regulation.
5. Response of either output with the opposite output held at half of the total
output power.
6. Input step transition time >10 µs.
7. Input step transition time <100 µs.
5
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
PWM
Controller
ID
IC
Limit Ref.
Output
Common
Positive
Output
Positive
Input
Inhibit
Input
Common
5 µH
2 µF
BLOCK DIAGRAM
FIGURE 1: MHF+ SINGLE OUTPUT
PIN OUT
MHF+ 28 12 D F / 883
Base Model
Input Voltage
Output Voltage
Screening
Number of Outputs
(S = single, D = dual)
(R = decimal point, 3R3 = 3.3 Vout)
(Standard screening has no designator
in this position.)
Case Option
(Non-flanged case has no designator in
this position)
6
MHF+ SERIES
SINGLE AND DUAL
15 WATT
DC/DC C
ONVERTERS
SMD NUMBERS
MODEL NUMBERING KEY
Pin Single Output MHF+2828S Dual Output
(Except MHF+2828S)
1 Inhibit Inhibit Inhibit
2 No connection Positive Output Positive Output
3 Output Common (See note 1, below) Output Common
4 Positive Output Output Common Negative Output
52Sync Sync Sync
6 Case Ground Case Ground Case Ground
7 Input Common Input Common Input Common
8 Positive Input Positive Input Positive Input
1. Pin 3 of MHF+2828S will provide 14 Vout referenced to output common (pin 4).
2. If Sync is not used, pin 5 should be connected to input common.
FIGURE 2: PIN OUT
STANDARD MICROCIRCUIT
DRAWING (SMD)
IN PROCESS
5962-9213901HXC
IN PROCESS
5962-9166401HXC
5962-9160101HXC
5962-9689801HXC
5962-9555901HXC
5962-9214401HXC
5962-9161401HXC
MHF+
SIMILAR PART
MHF+283R3S/883
MHF+2805S/883
MHF+285R2S/883
MHF+2812S/883
MHF+2815S/883
MHF+2828S/883
MHF+2805D/883
MHF+2812D/883
MHF+2815D/883
BOTTOM VIEW
MHF+ SINGLE AND DUAL
NON-FLANGED OR FLANGED
Dot on top of cover
indicates pin one.
Dotted line outlines flanged package option.
1 2345
876
For exact specifications for an SMD product, refer to the SMD
drawing. Call your Interpoint representative for status on the
MHF+ SMD releases which are “in process”. SMDs can be
downloaded from
http://www.dscc.dla.mil/programs/smcr
See pages 9 and 10 for dimensions.
Flanged SMDs have the suffix HZC instead of HXC.
7
MHF+ SERIES
SINGLE AND DUAL
15 WATT
DC/DC C
ONVERTERS
Typical Performance Curves: 25°C Tc , 28 VDC Vin, 100% load, free run, unless otherwise specified.
FIGURE 6FIGURE 8
OUTPUT POWER (Watts)
MHF+2805D EFFICIENCY
EFFICIENCY (%)
40
90
80
70
60
50
2
46 81012
40V
28V
16V
OUTPUT POWER (Watts)
MHF+2815D EFFICIENCY
EFFICIENCY (%)
40
90
80
70
60
50
2 4 6 8 10 12 14
40V
28V
16V
OUTPUT POWER (Watts)
MHF+2805S EFFICIENCY
EFFICIENCY (%)
40
90
80
70
60
50
246 81012
16V
28V
40V
FIGURE 3
OUTPUT POWER (Watts)
MHF+2812S EFFICIENCY
EFFICIENCY (%)
40
90
80
70
60
50
2
46 8101214
16V
40V
28V
15
FIGURE 4
OUTPUT POWER (Watts)
MHF+2812D EFFICIENCY
EFFICIENCY (%)
40
90
80
70
60
50
2468101214
40V
28V
16V
15
FIGURE 7
FIGURE 5
OUTPUT POWER (Watts)
MHF+2815S EFFICIENCY
EFFICIENCY (%)
40
90
80
70
60
50
2468101214
16V
40V
15
28V
FREQUENCY (kHz)
MHF+ SERIES AUDIO REJECTION
ATTENUATION (dB)
–1000.1 1 10 100
–90
–80
–70
–60
–50
–40
–20
–10
0
–30
FIGURE 9
1ms/div
16V TO 40V
MHF+2805S STEP LINE RESPONSE
500mV/div.
V
IN
20V/div.
VOUT
FIGURE 10 FIGURE 11
50µs/div
50% 100%
MHF+2805S STEP LOAD RESPONSE
100mV/div.
50% to 100%
100% to 50%
MHF+ SERIES
SINGLE AND DUAL
15 WATT
DC/DC C
ONVERTERS
8
Typical Performance Curves: 25°C Tc , 28 VDC Vin, 100% load, free run, unless otherwise specified.
FIGURE 18 FIGURE 20
POSITIVE OUTPUT LOAD (% OF TOTAL LOAD)
–VOUT WITH SHIFT IN LOAD BALANCE
CROSS REGULATION
–V
OUT
VOLTAGE CHANGE (%)
–10 1000 20 40 60 80
–5
0
5
10
2812D
2815D
2805D
OUTPUT POWER (Watts)
50 mV DROP
LOW LINE DROPOUT VS. LOAD
INPUT VOLTAGE (Volts)
10 11 12 13 14 15
14
15
16
MHF+2812S&D
MHF+2815S&D
MHF+2805S&D
13
12
50µs/div
50% 100%
MHF+2815D +V
OUT
STEP LOAD RESPONSE
100mV/div.
50% to 100%
100% to 50% PO= 7.5 W
FIGURE 15
50µs/div
20% 100%
MHF+2815D +VOUT STEP LOAD RESPONSE
100mV/div.
20% to 100%
100% to 20%
PO= 7.5 W
FIGURE 16
OUTPUT LOAD (%)
COND. A: 50% LOAD +V; 50% to 10% –V
COND. B: 50% LOAD –V; 50% to 10% +V
MHF+2805D/MHF+2812D/MHF+2815D
CROSS REGULATION
–V
OUT
VOLTAGE CHANGE (%)
–10
0
10
10 20 30 40 50
–8
–6
–4
–2
2
4
6
8
2815D
2812D
2812D
COND B
COND A
2805D
2805D
FIGURE 19
FIGURE 17
2 ms/div
MHF+2815D TURN-ON INTO FULL LOAD
20V/div.
V
IN
5V/div.
+VOUT
–VOUT
FIGURE 12 FIGURE 14
200µs/div
10% 100%
MHF+2805S STEP LOAD RESPONSE
100mV/div.
10% to 100%
100% to 10%
1 ms/div
16V TO 40V
MHF+2815D STEP LINE RESPONSE
200mV/div.
V
IN
20V/div.
+VOUT
2 ms/div
MHF+2805S TURN-ON INTO FULL LOAD
1V/div.
V
IN
20V/div.
VOUT POUT= 12W
FIGURE 13
9
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
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.
CASE E
BOTTOM VIEW
See Figure 22
for pin configurations.
Squared corner and dot on top
of case indicate pin one.
1.460 max
(37.08)
1.130 max
(28.70)
Materials
Header Cold Rolled Steel/Nickel/Gold
Cover Kovar/Nickel
(SMHF Series
Cold Rolled Steel/Nickel/Gold)
Pins #52 alloy/Gold
compression 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.
FIGURE 21: CASE E MAXIMUM DIMENSIONS
0.000
0.205
(5.21)
0.505
(12.83)
0.705
(17.91)
0.905
(22.99)
1.105
(28.07)
0.330 max
(8.38)
0.000
0.25 (6.35)
0.000
0.160
(4.06)
0.960
(24.38)
1 2345
0.030 dia.
(0.76)
876
MHF+ Series Single and Dual: Screening – Standard, ES, or 883
BOTTOM VIEW CASE E1
0.330 max
(8.38)
0.000
0.25 (6.35)
Projection Weld
Seam Seal Squared corner and dot on top
of case indicate pin one.
FIGURE 22: CASE E1
10
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
Materials
Header Cold Rolled Steel/Nickel/Gold
Cover MHF+ Series and FMH Filter
Kovar/Nickel
SMHF
Cold Rolled Steel/Nickel
Pins #52 alloy (all cases)
compression glass seal
Case dimensions in inches (mm)
Tolerance ±0.005 (0.13) for three decimal places
±0.01 (0.2) for two decimal places
unless otherwise specified
CASE G
BOTTOM VIEW
Flanged package
See Figure 24
for pin configuration
2.005 max
(50.93)
1.130 max
(28.70)
Squared corner and dot on top
of case indicate pin one.
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.
Flange Thickness: 0.047 (1.19)
FIGURE 23: CASE G MAXIMUM DIMENSIONS
11
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
1.590 (40.39)
0.128 dia
(3.25)
0.030 dia.
(0.76)
Flanged cases: Designator "F" required in Case Option position of model number
MHF+ Series Single and Dual: Screening – Standard, ES, or 883
BOTTOM VIEW CASE G1
0.000
0.205 (5.21)
0.505 (12.83)
0.705 (17.91)
0.905 (22.99)
1.105 (28.07)
0.000
0.160
(4.06)
0.960
(24.38)
1 2345
876
0.140 (3.56)
0.560
(14.22)
0.330 max.
(8.38)
0.000
0.25 (6.35)
0.330 max.
(8.38)
0.000
0.25 (6.35)
Squared corner and dot on top
of case indicate pin one.
Projection Weld
Seam Seal
FIGURE 24: CASE G1
12
DC/DC C
ONVERTERS
MHF+ SERIES
SINGLE AND DUAL
15 WATT
TEST STANDARD /ES /883 (Class H)*
PRE-CAP INSPECTION
Method 2017, 2032 yes yes yes
TEMPERATURE CYCLE (10 times)
Method 1010, Cond. C, -65°C to 150°C no no yes
Method 1010, Cond. B, -55°C to 125°C no yes no
CONSTANT ACCELERATION
Method 2001, 3000 g no no yes
Method 2001, 500 g no yes no
BURN-IN
Method 1015, 160 hours at 125°C no no yes
96 hours at 125°C case (typical) no yes no
FINAL ELECTRICAL TEST MIL-PRF-38534, Group A
Subgroups 1 through 6: -55°C, +25°C, +125°C no no yes
Subgroups 1 and 4: +25°C case yes yes no
HERMETICITY TESTING
Fine Leak, Method 1014, Cond. A no yes yes
Gross Leak, Method 1014, Cond. C no yes yes
Gross Leak, Dip (1 x 10-3) yes no no
FINAL VISUAL INSPECTION
Method 2009 yes yes yes
Test methods are referenced to MIL-STD-883 as determined by MIL-PRF-38534.
*883 products are built with element evaluated components and are 100% tested and guaranteed over the full military temperature
range of –55°C to +125°C.
TABLE 1: ENVIRONMENTAL SCREENING
21621-001-DTS Rev B This revision supercedes all previous releases.
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. MHF+ Series is a trademark of Interpoint.
Copyright © 1999-2000 Interpoint. All rights reserved.
Contact Information:
Interpoint Headquarters USA
Phone: 1-800-822-8782
+425-882-3100
Email: power@intp.com
www.interpoint.com
Interpoint UK
Phone: +44-1252-815511
Email: poweruk@intp.com
Interpoint France
Phone: +33-134285455
Email: powerfr@intp.com
1
Size (max.): Non flanged, case E2, 1.460 x 1.130 x 0.330 inches (37.08 x 28.70 x 8.38 mm)
Flanged , case G2, 2.005 x 1.130 x 0.330 inches (50.93 x 28.70 x 8.38 mm)
See Figures 13 - 16 for dimensions.
Weight: 32 grams maximum.
Screening: Standard, ES, or 883 (Class H). See Table 1 for screening options.
DESCRIPTION
Interpoint’s MHF+ Series™ Triple DC/DC converters provide a wide
input voltage range of 16 to 48 VDC delivering 15 watts of total
output power with output voltages of +5 and ±12 or +5 and ±15
VDC. The main output, +5 VDC, will supply up to 7.5 watts and the
auxiliaries will supply up to 7.5 watts of combined power. Full power
operation at -55° C to +125°C plus the ability to withstand transients
of up to 80 V for up to 120 milliseconds make these converters an
ideal choice for your high reliability systems.
CONVERTER DESIGN
MHF+ Triple Series of DC/DC converters incorporate dual-phase,
phase-shifted technology with a continuous flyback topology. This
design eliminates a minimum load requirement on the main output
and eliminates cross regulation effects between the main output
voltage and the auxiliary output voltages. The phase-shifted design
offers a further benefit in reduced input and output ripple.
INHIBIT FUNCTION
An open collector, TTL compatible, inhibit terminal (pin 1) provides
shut-down and start-up control. Applying a logic level low (<0.8 V),
referenced to input common, will disable the output of the converter.
When inhibited input current is reduced to 5 mA or less and there is
no generation of switching noise. The inhibit terminal typically sinks
3 mA when the converter is inhibited.
Leaving the terminal open or pulling it high will enable the converter.
Use an open collector interface for logic high voltages of up to 11
volts. (Refer to Figure 2 for a connection diagram.) An open collector
interface is not required if the logic high is in excess of the open
circuit voltage of the inhibit terminal, 11 volts, but less than 40 volts.
SOFT START FEATURE
The soft-start feature provides a controlled 20 milliseconds turn-on
to minimize inrush current and reduce overshoot at initial start-up or
when inhibit is released.
SYNCHRONIZATION
To synchronize the converter’s switching frequency to a system
clock apply the clock signal to the sync terminal (pin 7). When
multiple converters are powered from a single power source, asyn-
chronous (free run) operation will result in lower peak noise for
common spectral peaks, but synchronous operation will eliminate
any possibility of interference frequencies in the low audio band.
Source impedance of the signal should be less than 100 ohms and
the transition time should be less than 100 nanoseconds. The
capacitively coupled sync input will synchronize on a differential
signal of as low as 4 volts to as high as 10 volts. If the sync function
is not used, the terminal should be left open.
SHORT CIRCUIT PROTECTION
Internal current limiting circuitry protects all three outputs against
short circuits. When output power exceeds approximately 130% of
maximum output power, the output currents are limited. In addition,
separate current limiting circuitry protects each output individually
resulting in normal operation of either the main or the auxiliaries,
whichever is not in a shorted condition.
PACKAGING
MHF+ Triple converters are packaged in hermetically sealed metal
cases. MHF+ Triple converters can be purchased in a flanged or
non-flanged case. The flanged option provides increased heat dissi-
pation and also provides greater stability when mechanically
secured.
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
MHF+ SERIES TRIPLE
15 WATT
FEATURES
• –55° to +125°C operation
• 16 to 48 VDC input
• Fully Isolated
• Optocoupler feedback
• Fixed frequency 450 kHz
• Topology – Current Mode Flyback
• Transient protection 80 V/120 ms
• Inhibit and sync functions
• Indefinite short circuit protection
• Undervoltage lockout
• Up to 76% efficiency
MODELS
VDC OUTPUT
TRIPLE OUTPUT
+5 and ±12
+5 and ±15
RECOMMENDED OPERATING CONDITIONS
TYPICAL CHARACTERISTICSABSOLUTE MAXIMUM RATINGS
Input Voltage
• 16 to 48 VDC
Power Dissipation (Pd)
• 12 watts
Output Power
• 15 watts
Lead Soldering Temperature (10 sec per pin)
• 300°C
Storage Temperature Range (Case)
• –65°C to +150°C
2
MHF+ SERIES TRIPLE
15 WATT
DC/DC C
ONVERTERS
Output Voltage Temperature Coefficient
• 150 ppm/°C typical
Current Limit
• 130% typical
Isolation
• 100 megohm minimum at 500 V
Conversion Frequency
• Free run 375 minimum, 500 kHz maximum
• External sync range 400 to 600 kHz
Inhibit Pin Voltage (unit enabled)
• 10 V typical
Input Voltage Range
• 16 to 48 VDC continuous
• 80 V for up to 120 msec
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
SYNC AND INHIBIT
Sync 400 to 600 kHz
• Duty cycle 40% to 60%
• Logic low 0.8 V max
• Logic high 4.5 V min, 10.0 V max
• If not used, leave unconnected
• Referenced to input common
Inhibit: TTL Open Collector
• Logic low (output disabled)
Logic low voltage ≤0.8 V max
Inhibit pin current 3.0 typ, 5.0 max
• Referenced to input common
Logic high (output enabled)
Open collector
Unconnected or 11 to 40 V
PWM CM
CONTROLLER
0°
180°
PWM CM
CONTROLLER
INPUT
COMMON FEEDBACK ISOLATOR
FEEDBACK ISOLATOR
OUTPUT
COMMON
+ AUX.
OUTPUT
–AUX.
OUTPUT
POSITIVE
INPUT
SYNC
+5 OUTPUT
FIGURE 1: BLOCK DIAGRAM
3
MHF+ SERIES TRIPLE
15 WATT
DC/DC C
ONVERTERS
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
MHF+28512T MHF+28515T
PARAMETER CONDITION MIN TYP MAX MIN TYP MAX UNITS
OUTPUT VOLTAGE MAIN 4.95 5.0 5.05 4.925 5.0 5.05
+ AUXILIARY 11.64 12.0 12.36 14.55 15.0 15.45 VDC
– AUXILIARY 11.64 12.0 12.36 14.55 15.0 15.45
OUTPUT CURRENT1MAIN 0 —1.5 0 —1.5
+ AUXILIARY ——0.416 ——0.333 A
– AUXILIARY ——0.416 ——0.333
TOTAL ——2.125 ——2.0
OUTPUT POWER2MAIN ——7.5 ——7.5
+ AUXILIARY ——5——5W
– AUXILIARY —— 5——5
TOTAL ——15 ——15
OUTPUT RIPPLE 10 kHz to 2 MHz MAIN —20 75 —20 75
VOLTAGE 10 kHz to 2 MHz ± AUXILIARY —30 90 —30 112 mV p-p
LINE REGULATION3MAIN —25 75 —25 75 mV
VIN = MIN. TO MAX. ±AUXILIARY —120 240 —150 300
LOAD REGULATION3, 4 MAIN —25 60 —25 60 mV
± AUXILIARY —120 240 —150 300
CROSS REGULATION5– AUXILIARY ——1200 ——1500 mV
INPUT VOLTAGE CONTINUOUS 16 28 48 16 28 48 VDC
TRANSIENT 120 ms ——80 ——80 V
INPUT CURRENT NO LOAD3—20 35 —20 35
FULL LOAD —705 724 —705 724 mA
INHIBITED3—35 —35
INPUT RIPPLE CURRENT 10 kHz to 10 MHz —20 50 —20 50 mA p-p
EFFICIENCY 74 76 —74 76 —%
LOAD FAULT6POWER DISSIPATION
MAIN3——12 ——12 W
±AUXILIARY ——12 ——12
STEP LOAD TRANSIENT
RESPONSE3, 7, 8 MAIN ——850 ——850 mV pk
± AUXILIARY ——750 ——750
RECOVERY MAIN —58 —58 ms
RECOVERY ±AUX. —23 —23
START-UP3, DELAY EACH OUTPUT —10 25 —10 25 ms
Notes
1. The sum of the 12 volt auxiliary output currents may not exceed 625 mA.
The sum of the 15 volt auxiliary output currents may not exceed 500 mA.
2. The sum of the auxiliary output power may not exceed 7.5 watts.
3. Case temperature –55°C to +125°C.
4. Load regulation for the +5 is specified at 0.0 to 1.5 A with the aux. both held
at 3.76 W (313 mA for the ±12, 250 mA for the ±15). Load regulation for the
aux. is specified as both aux. from 0.0 to 3.76 W (313 mA for ±12, 250 mA
for ±15) at the same time with the +5 held at 1.5 A.
5. Cross regulation only occurs between the two auxiliaries and is measured on
–aux. +5 is held constant at 1.0 A. Cross regulation is specified for two
conditions:
Negative aux.= 3.76 W; positive aux.= 0.37 W to 3.76 W.
Negative aux. = 0.37 W to 3.76 W; positive aux. = 3.76 W.
6. Load fault = <0.05 Ω.
7. Transition time is 2 – 10 µs.
8. Time to settle to within 1% of Vout final value.
Positive Input
1
5
28V
Input Common
FMH-461
EMI FILTER
Positive Output
Output Common
3
Positive Input
9
8Input Common
MHF+ TRIPLE
2
4
Case*
*The case ground connection should be as low an impedance as possible to minimize EMI.
Direct contact of baseplate to chassis ground provides the lowest impedance.
Chassis Ground
6
+5
Load
Positive Input
9
7
1
8
2
4
5
28V
Sync In
Inhibit
Input Common
+5 Output
Output Common
– Aux. Output
+ Aux.
Load
3
– Aux.
Load
+ Aux. Output
0.01 F
5.1k
9
1
8
200 pF
3.9 K
10 K
INHIBIT
MHF+ Triple
INPUT
COMMON
POSITIVE INPUT
10 k
1N4148
2N3501
4
MHF+ SERIES TRIPLE
15 WATT
DC/DC C
ONVERTERS
CONNECTION DIAGRAMS
FIGURE 2: INHIBIT INTERFACE
FIGURE 3: AC COUPLING OF SYNC SIGNAL
FIGURE 4: EMI FILTER CONNECTION
If the sync terminal ([pin 7) is not used, it must be left floating.
The ac coupling shown will prevent sync signal failure.
SMD NUMBERS
PIN OUT
MHF+ 28 512 T F / ES
Base Model
Input Voltage
Output Voltage
Screening
Number of Outputs
(T = triple)
(Main and aux. Vout)
Case Option
(Non-flanged case has no designator in
this position)
(Standard screening has no designator
in this position.)
5
MHF+ SERIES TRIPLE
15 WATT
DC/DC C
ONVERTERS
MODEL NUMBERING KEY
Pin Description
1 Inhibit
2 Main (+5 V) Output
3 Output Common
4 Positive Auxiliary Output
5 Negative Auxiliary Output
6 Case Ground
7 Sync In
8 Input Common
9 Positive Input
If Sync is not used, leave it unconnected.
FIGURE 5: PIN OUT BOTTOM VIEW
STANDARD MICROCIRCUIT
DRAWING (SMD)
5962-9560101HXC
5962-9560201HXC
MHF+
SIMILAR PART
MHF+28512T/883
MHF+28515T/883
Dotted line outlines flanged package option.
1 2345
986
7
Squared corner and dot on top
of package indicate pin one.
BOTTOM VIEW
MHF+ Triple
For exact specifications for an SMD product, refer to the SMD drawing. SMDs
can be downloaded from
http://www.dscc.dla.mil/programs/smcr
Refer to Figures 13 - 16 for dimensions.
Flanged SMDs have the suffix HZC instead of HXC.
6
MHF+ SERIES TRIPLE
15 WATT
DC/DC C
ONVERTERS
Typical Performance Curves: 25°C Tc , 28 VDC Vin, 100% load, free run, unless otherwise specified.
FIGURE 9FIGURE 11
MHF+28512T TURN ON INTO FULL LOAD
MAIN
5 ms / div.
+5 VDC
2 V / div.
MHF+28515T has a similar response
10 V / div.
VIN
INPUT
GND
+5
GND
MHF+28512T TURN ON INTO FULL LOAD
AUXILIARIES
5 ms / div.
–12 VDC
5 V / div.
+12 VDC
MHF+28515T has a similar response
10 V / div.
VIN
16
EFFICIENCY
55
80
60
65
70
75
46
810 12 14
16 V
28 V
48 V
2
MHF+28512T EFFICIENCY
OUTPUT POWER (W)
FIGURE 6
16
EFFICIENCY
55
80
60
65
70
75
246
810 12 14
16 V
48 V
MHF+28515T EFFICIENCY
OUTPUT POWER (W)
28 V
FIGURE 7
MHF+28512T TURN ON INTO FULL LOAD
MAIN
5 ms / div.
+5 VDC
2 V / div.
MHF+28515T has a similar response
10 V / div.
VIN
INPUT
GND
+5
GND
FIGURE 10
FIGURE 8
MHF+28512T has a similar response
MHF+ 28515T STEP LINE RESPONSE
500 mV / div.
5 ms / div.
–15 VDC
±15 = 250 mA EACH, +5 = 1.5 A
200 mV / div.
INPUT V: 16 TO 40 VDC,
+15 VDC
5 VDC
MAXIMUM OUTPUT POWER (W)
INPUT VOLTAGE
LOW LINE DROPOUT
MHF+28515T
MHF+28512T
11.5
11
10.5
9.5
9
8.5
10
246810121416
FIGURE 12
7
DC/DC C
ONVERTERS
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.
CASE E
BOTTOM VIEW
See Figure 14
for pin configurations.
Squared corner and dot on top
of case indicate pin one.
1.460 max
(37.08)
1.130 max
(28.70)
Materials
Header Cold Rolled Steel/Nickel/Gold
Cover Kovar/Nickel
(SMHF Series
Cold Rolled Steel/Nickel/Gold)
Pins #52 alloy/Gold
compression 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.
FIGURE 13: CASE E MAXIMUM DIMENSIONS
0.000
0.205
(5.21)
0.505
(12.83)
0.705
(17.91)
0.905
(22.99)
1.105
(28.07)
0.000
0.160
(4.06)
0.960
(24.38)
0.030 dia.
(0.76)
MHF+ Series Triple: Screening – Standard, ES, or 883
12345
876
9
BOTTOM VIEW CASE E2
0.330 max
(8.38)
0.000
0.25 (6.35)
0.330 max
(8.38)
0.000
0.25 (6.35)
Projection Weld
Seam Seal Squared corner and dot on top
of case indicate pin one.
FIGURE 14: CASE E2
MHF+ SERIES TRIPLE
15 WATT
8
DC/DC C
ONVERTERS
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.
Materials
Header Cold Rolled Steel/Nickel/Gold
Cover MHF+ Series and FMH Filter
Kovar/Nickel
Pins #52 alloy (all cases)
compression glass seal
Case dimensions in inches (mm)
Tolerance ±0.005 (0.13) for three decimal places
±0.01 (0.2) for two decimal places
unless otherwise specified
CASE G
BOTTOM VIEW
Flanged package
See Figure 16
for pin configuration
2.005 max
(50.93)
1.130 max
(28.70)
Squared corner and dot on top
of case indicate pin one.
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.
Flange Thickness: 0.047 (1.19)
FIGURE 15: CASE G MAXIMUM DIMENSIONS
1.590 (40.39)
0.128 dia
(3.25)
0.030 dia.
(0.76)
Flanged case: Designator (F) required in Case Option position of model number.
MHF+ Series Triple: Screening – Standard, ES, or 883
BOTTOM VIEW CASE G2
0.000
0.205 (5.21)
0.505 (12.83)
0.705 (17.91)
0.905 (22.99)
1.105 (28.07)
0.000
0.160
(4.06)
0.960
(24.38)
12345
98
67
0.140 (3.56)
0.560
(14.22)
0.330 max.
(8.38)
0.000
0.25 (6.35)
0.330 max.
(8.38)
0.000
0.25 (6.35)
Projection Weld
Seam Seal Squared corner and dot on top
of case indicate pin one.
FIGURE 17: CASE G2
MHF+ SERIES TRIPLE
15 WATT
9
DC/DC C
ONVERTERS
MHF+ SERIES TRIPLE
15 WATT
TEST STANDARD /ES /883 (Class H)*
PRE-CAP INSPECTION
Method 2017, 2032 yes yes yes
TEMPERATURE CYCLE (10 times)
Method 1010, Cond. C, -65°C to 150°C no no yes
Method 1010, Cond. B, -55°C to 125°C no yes no
CONSTANT ACCELERATION
Method 2001, 3000 g no no yes
Method 2001, 500 g no yes no
BURN-IN
Method 1015, 160 hours at 125°C no no yes
96 hours at 125°C case (typical) no yes no
FINAL ELECTRICAL TEST MIL-PRF-38534, Group A
Subgroups 1 through 6: -55°C, +25°C, +125°C no no yes
Subgroups 1 and 4: +25°C case yes yes no
HERMETICITY TESTING
Fine Leak, Method 1014, Cond. A no yes yes
Gross Leak, Method 1014, Cond. C no yes yes
Gross Leak, Dip (1 x 10-3) yes no no
FINAL VISUAL INSPECTION
Method 2009 yes yes yes
Test methods are referenced to MIL-STD-883 as determined by MIL-PRF-38534.
*883 products are built with element evaluated components and are 100% tested and guaranteed over the full military temperature
range of –55°C to +125°C.
TABLE 1: ENVIRONMENTAL SCREENING
Contact Information:
www.interpoint.com
Interpoint Headquarters USA
Phone: 1-800-822-8782
+425-882-3100
Email: power@intp.com
Interpoint UK
Phone: +44-1252-815511
Email: poweruk@intp.com
Interpoint France
Phone: +33-134285455
Email: powerfr@intp.com
21623-002-DTS Rev B This revision supercedes all previous releases.
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. MHF+ Series is a trademark of Interpoint.
Copyright © 1995 - 1999 Interpoint. All rights reserved.
