F
EATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
–55° to +100°C operation
19 to 40 VDC input
Fully Isolated
Magnetic feedback
Fixed frequency, 600 kHz typical
Topology – Single Ended Forward
80 V for up to 50 ms transient protection
Inhibit function – input and output
Sync function – input and output
Output trim on single output models
Indefinite short circuit protection
Remote sense on single output models
Up to 87% efficiency
Parallelable up to 228 watts
DC/DC C
ONVERTERS
28 V
OLT
I
NPUT
MFLHP SERIES
100 WATT
MODELS
VDC O
UTPUT
SINGLE
5
12
15
DUAL
±5
±12
±15
Size (max.): 3.005 x 1.505 x 0.400 inches (76.33 x 38.23 x 10.16 mm)
See Section B8, case U1, for dimensions.
Weight:
100 grams maximum
Screening: Standard or ES. See Section C2 for screening options,
see Section A5 for ordering information.
DESCRIPTION
The MFLHP Series™ 28 volt DC/DC converters are rated up to 100
watts output power over a –55° to +100°C temperature range with a
28 Vdc nominal input. On dual output models, up to 70% of the rated
output power can be drawn from either the positive or negative
outputs. Current sharing allows the units to be paralleled for total
power of up to 270 watts. The welded, hermetically sealed package
is only 3.005 x 1.505 x 0.400 inches, giving the series an overall
power density of up to 67 watts per cubic inch.
I
NHIBIT
The MFLHP Series converters have two TTL compatible inhibit
terminals (INH1 and INH2) that can be used to disable power
conversion, resulting in a very low quiescent input current. An open
collector TTL compatible low (<0.8 volts) is required between INH1
(pin 4) and Input Common (pin 2) to inhibit the converter. An open
collector TTL compatible low (<0.5 volts) is required between INH2
(pin 12) and Output Common (pin 8) to inhibit the converter. The
application of intermediate voltages to these pins (1.5 to 10.5 volts)
should be avoided.
D
ESIGN
F
EATURES
The MFLHP Series converters are switching regulators that use a
quasi-square wave, single ended forward converter design with a
constant switching frequency of 600 kHz.
Isolation between input and output circuits is provided with a trans-
former in the forward path and wide bandwidth magnetic coupling in
the feedback control loop. The MFLHP Series uses a unique dual
loop feedback technique that controls output current with an inner
feedback loop and output voltage with a cascaded voltage mode
feedback loop.
The additional secondary current mode feedback loop improves
transient response in a manner similar to primary current mode
control and allows for ease of paralleling.
Tight load regulation is achieved through a wide-bandwidth
magnetic feedback circuit. The output voltage on single MFLHP
models can be easily trimmed by adding an external resistor. (See
Figure 1 for voltage changes with different resistor values.)
C
URRENT
S
HARING AND
P
ARALLEL
O
PERATION
Multiple MFLHP converters may be used in parallel to drive a
common load (see Figure 2). In this mode of operation the load
current is shared by two or three MFLHP converters. In current
sharing mode, one MFLHP converter is designated as a master. The
SLAVE pin (pin 11) of the master is left unconnected and the
MSTR/INH2 pin (pin 12) of the master is connected to the SLAVE
pin (pin 11) of the slave units. The units designated as slaves have
the MSTR/INH2 pin (pin 12) connected to the SNS RTN pin (pin 9).
Figure 2 shows the typical setup for two or three units in parallel.
Note that synchronizing the units together (though shown in the
figure) is not required for current sharing operation. A second slave
unit may be placed in parallel with a master and slave; this requires
the TRI pin (pin 3) of the master unit to be connected to the SNS
RTN pin (pin 9).
When paralleled, 76% of the total combined power ratings of the
MFLHP converters are available at the load. Overload and short
circuit performance are not adversely affected during parallel
operation.
B2-19
MFLHP SERIES
100 WATT
ABSOLUTE MAXIMUM RATINGS
Input Voltage
• 19 to 40 VDC
Power Dissipation (Pd)
• 20 watts
Output Power
• 80 to 100 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
SYNC IN AND INHIBIT (INH1, INH2)
Sync In (525 to 675 kHz)
• Duty cycle 40% min, 60% max
• Logic low 0.8 V max
• Logic high 4.5 V min
• Referenced to input common
• If not used, connect to input common
Sync Out - Referenced to input common
Inhibit (INH1, INH2) TTL Open Collector
• Logic low (output disabled)
Current –10 to –5 mA
INH1 referenced to input common
Logic low 0.8 V max
INH2 referenced to output common
Logic low 0.5 V max
• Logic high (output enabled)
Open collector
TYPICAL CHARACTERISTICS
Output Voltage Temperature Coefficient
• 100 ppm/°C typical
Input to Output Capacitance
• 150 pF typical
Isolation
• 100 megohm minimum at 500 V
Audio Rejection
• 50 dB typical
Conversion Frequency
• Free run mode 600 kHz typical
550 kHz min, 650 kHz. max
• External sync range 525 to 675 kHz
Inhibit Pin Voltage (unit enabled)
• INH1 = 9 to12 V, INH2 = 6 to 9 V
RECOMMENDED OPERATING CONDITIONS
Input Voltage Range
• 19 to 40 VDC continuous
• 80 V for 50 msec transient
Case Operating Temperature (Tc)
• –55 to +100°C full power
• –55 to +135°C absolute
Derating Output Power/Current
• Linearly from 100% at 100°C to 0% at 135°C
PINS NOT USED
TR1, Master, and Slave
If not used, leave unconnected
Electrical Characteristics: –50°C to +100°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
SINGLE OUTPUT MODELS
PARAMETER
OUTPUT VOLTAGE
OUTPUT CURRENT
OUTPUT POWER
OUTPUT RIPPLE
VOLTAGE 10 k - 2 MHz
LINE REGULATION
LOAD REGULATION
INPUT VOLTAGE
NO LOAD TO FULL
INPUT CURRENT
CONDITION
25°C
V
IN
= 19 to 40 VDC
V
IN
= 19 to 40 VDC
Tc = 25°C
Tc = –55°C to +100°C
V
IN
= 19 to 40 VDC
NO LOAD TO FULL
CONTINUOUS
TRANSIENT
1
50 ms
NO LOAD
FULL LOAD
INHIBITED - INH1
INHIBITED - INH2
10 kHz - 10 MHz
Tc = 25°C
POWER DISSIPATION
SHORT CIRCUIT
RECOVERY
50% – 100% – 50%
TRANSIENT
RECOVERY
3
19 – 40 – 19 VDC
TRANSIENT
4
RECOVERY
3
DELAY
OVERSHOOT
MFLHP2805S
MIN
4.95
0
0
—
—
—
—
19
—
—
—
—
—
—
77
—
—
—
—
—
—
—
—
TYP MAX
5.00 5.05
—
16
—
15
30
0
0
28
—
70
3.6
9
35
15
80
15
1.5
350
1.5
250
200
3.5
0
80
35
75
20
20
40
80
120
3.73
14
70
50
—
20
4
450
3.0
400
300
6
25
MFLHP2812S
MIN TYP MAX
11.88 12.00 12.12
0
—
7.5
0
—
—
—
—
19
—
—
—
—
—
—
83
—
—
—
—
—
—
—
—
—
30
45
0
0
28
—
50
3.8
9
35
15
86
15
1.5
450
1.5
250
200
3.5
0
90
75
125
20
20
40
80
80
3.95
14
70
50
—
20
4
700
3.0
400
300
6
50
MFLHP2815S
MIN TYP MAX
14.85 15.00 15.15
0
— 6.67
0
—
—
—
—
19
—
—
—
—
—
—
84
—
—
—
—
—
—
—
—
—
30
45
0
0
28
—
50
4.2
9
35
15
87
15
1.5
450
1.5
250
200
3.5
0
100
85
150
20
20
40
80
80
4.40
14
70
50
—
20
4
700
3.0
400
300
6
50
UNITS
VDC
A
W
mV p-p
mV
mV
VDC
V
mA
A
mA
INPUT RIPPLE
CURRENT
EFFICIENCY
LOAD FAULT
2
Tc = 25°C
STEP LOAD RESP.
mA pp
%
W
ms
mV pk
ms
mV pk
µs
ms
mV pk
STEP LINE RESP.
START-UP
Notes
1. Unit will shut down above approximately 45V but will be undamaged and
will restart when voltage drops into normal range.
2. Indefinite short circuit protection not guaranteed above 100°C case.
3. Recovery time is measured from application of the transient to point at
which Vout is within 1% of final value.
4. Transition time
≥
10 µs.
B2-20
DC/DC C
ONVERTERS
DUAL OUTPUT MODELS
PARAMETER
OUTPUT VOLTAGE
Tc = 25°C
OUTPUT CURRENT
1
V
IN
= 19 TO 40 VDC
OUTPUT POWER
V
IN
= 19 TO 40 VDC
OUTPUT RIPPLE
VOLTAGE
LINE REGULATION
V
IN
= 19 TO 40 VDC
LOAD REGULATION
NO LOAD TO FULL
CROSS REGULATION
Tc = 25°C
INPUT VOLTAGE
NO LOAD TO FULL
INPUT CURRENT
Tc = 25°C
CONDITIONS
+V
OUT
–V
OUT
EACH OUTPUT
TOTAL
EACH OUTPUT
TOTAL
10 kHz - 2 MHz
+V
OUT
–V
OUT
+V
OUT
–V
OUT
+V
OUT
–V
OUT
SEE NOTE 2
SEE NOTE 3
CONTINUOUS
TRANSIENT
4
50 ms
NO LOAD
FULL LOAD
INHIBITED - INH1
INHIBITED - INH2
10 kHz - 10 MHz
BALANCED LOAD
POWER DISSIPATION
SHORT CIRCUIT
RECOVERY
50 %–100%– 50% LOAD
TRANSIENT
RECOVERY
6
19 – 40 – 16 V
IN
TRANSIENT
7
RECOVERY
6
DELAY
OVERSHOOT
—
—
—
—
—
—
—
—
19
0
—
—
—
—
—
77
—
—
—
—
—
—
—
—
25
25
0
25
0
25
6
3
28
—
50
3.6
9
35
15
80
15
1.5
350
1.5
250
200
3.5
0
125
125
50
100
50
100
8
6
40
80
120
14
70
50
—
20
4.0
450
3.0
400
300
6
25
—
—
—
—
—
—
—
—
19
0
—
—
—
—
—
83
—
—
—
—
—
—
—
—
50
50
0
25
10
50
2
2
28
—
50
3.8
9
35
15
86
15
1.5
450
1.5
250
200
3.5
0
150
150
50
100
100
200
4
4
40
80
100
14
70
50
—
20
4.0
700
3.0
400
300
6
50
—
—
—
—
—
—
—
—
19
0
—
—
—
—
—
84
—
—
—
—
—
—
—
—
50
50
0
25
10
50
2
2
28
—
550
4.2
9
35
15
87
15
1.5
450
1.5
250
200
3.5
0
MFLHP2805D
MIN TYP MAX
4.95 5.00 5.05
4.92 5.00 5.08
0
0
0
0
—
—
—
—
11.2
16.0
56
80
MFLHP2812D
MIN TYP MAX
11.88 12.00 12.12
11.82 12.00 12.18
0
0
0
0
—
—
—
—
5.3
7.5
63
90
MFLHP SERIES
100 WATT
MFLHP2815D
MIN TYP MAX
14.85 15.00 15.15
14.77 15.00 15.23
0
0
0
0
—
—
—
—
4.67
6.67
70
100
200
200
50
100
100
200
4
4
40
80
100
14
70
50
—
20
4.0
700
3.0
400
300
6
50
mV
%
VDC
V
mA
A
mA
mA p-p
%
W
ms
mV pk
ms
mV pk
µs
ms
mV p
UNITS
VDC
A
W
Electrical Characteristics: –55°C to +100°C Tc, 28 VDC Vin, 100% load, free run, unless otherwise specified.
mV p-p
mV
INPUT RIPPLE
CURRENT
EFFICIENCY 25°C Tc
LOAD FAULT
5
Tc = 25°C
STEP LOAD
RESPONSE ± V
OUT
STEP LINE
RESPONSE ± V
OUT
START–UP
Notes
1. Up to 70% of the total output power is available from either output providing
the opposite output is simultaneously carrying 30% of the total power.
2. Effect on the
negative output under the following conditions:
+P
out
30% to 70%; –P
out
70% to 30%
3. Effect on the
negative output under the following conditions:
+P
out
50%; –P
out
10% to 50%
4. Unit will shut down above approximately 45V but will be undamaged and
will restart when voltage drops into normal range.
5. Indefinite short circuit protection not guaranteed above 100°C case.
6. Recovery time is measured from application of the transient to point at
which Vout is within 1% of final value.
7. Transition time
≥
10 µs.
B2-21
MFLHP SERIES
100 WATT
28V
+
–
DC/DC C
ONVERTERS
1
2
3
4
5
6
Positive Input
Input Common
TR1
INH1
Sync Out
Sync In
MSTR/INH2 12
Slave 11
Pos. Sense 10
9
Sense Return
8
Output Common
7
Positive Output
SINGLE OUTPUT MODELS CONNECTION DIAGRAMS - SENSE AND PARALLEL
Inhibit
Sync In
–
+
RL
REMOTE SENSE CONNECTION
1
2
3
Inhibit
Sync In
4
5
6
MSTR/INH2 12
11
Slave
10
Pos. Sense
9
Sense Return
8
Output Common
7
Positive Output
28V
+
–
Positive Input
Input Common
TR1
INH1
Sync Out
Sync In
RA
–
+
RL
OUTPUT VOLTAGE ADJUST CONNECTION
F
IGURE
1: S
ENSE
C
ONNECTIONS AND
T
RIM
T
ABLE
28V
+
–
1
2
3
4
5
6
Positive Input
Input Common
TR1
INH1
Sync Out
Sync In
MSTR/INH2 12
Slave 11
Pos. Sense
Sense Return
10
9
8
7
+
RL
–
Inhibit
Sync In
MASTER
Output Common
Positive Output
CONNECT ONLY WHEN 2 SLAVES ARE USED
1
2
3
4
5
6
Positive Input
Input Common
TR1
INH1
Sync Out
Sync In
MSTR/INH2 12
Slave 11
Pos. Sense 10
Sense Return 9
Output Common 8
7
Positive Output
SLAVE 1
1
2
3
4
5
6
Positive Input
Input Common
TR1
INH1
Sync Out
Sync In
MSTR/INH2 12
Slave 11
Pos. Sense 10
Sense Return 9
SLAVE 2
Output Common 8
7
Positive Output
F
IGURE
2: P
ARALLEL
C
ONNECTIONS
B2-22
DC/DC C
ONVERTERS
PIN OUT
Pin
1
2
3
4
5
6
7
8
9
10
11
12
Single Output
Positive Input
Input Common
Triple (TRI)
Inhibit 1 (INH1)
Sync Out
Sync In
Positive Output
Output Common
Sense Return
Positive Sense
Slave
Master / Inhibit 2
(MSTR/INH2)
Dual Output
Positive Input
Input Common
Triple (TRI)
Inhibit 1 (INH1)
Sync Out
Sync In
Positive Output
Output Common
Negative Output
No connection
Slave
Master / Inhibit 2
(MSTR/INH2)
Angled corner indicates pin one.
MFLHP SERIES
100 WATT
1
2
3
4
5
6
12
11
TOP VIEW
MFLHP
(Pin side, marked side)
10
9
8
7
See Section B8, case U1 for dimensions.
Pin 6 should be connected to input common if
external sync (Sync In) is not used.
Sense pins must be connected to their respective
outputs if not used.
F
IGURE
3: P
IN
O
UT
MODEL NUMBERING KEY
MFLHP 28 05 S / ES
Base Model
Input Voltage
Output Voltage
Number of Outputs
(S = single, D = dual)
Screening
(Standard screening has no designator
in this position.)
Typical Performance Curves: 25°C Tc , 28 VDC Vin, 100% load, free run, unless otherwise specified.
90
85
19V
90
85
19V
90
85
19V
Efficiency (%)
Efficiency (%)
Efficiency (%)
80
75
70
65
60
10
30
28V
40V
80
75
70
65
28V
80
75
70
65
40V
28V
40V
Output (Watts)
50
70
90
60
10
30
50
70
90
60
10
30
50
70
90
100
Output Power (Watts)
Output Power (Watts)
MFLHP2805S & MFLHP2805D
Efficiency
MFLHP2812S & MFLHP2812D
Efficiency
MFLHP2815S & MFLHP2815D
Efficiency
F
IGURE
4
F
IGURE
5
F
IGURE
6
B2-23
