MRH SERIES
15 WATT
DC/DC CONVERTERS
INHIBIT
TYPICAL CHARACTERISTICS
ABSOLUTE MAXIMUM RATINGS
Inhibit TTL Open Collector
• Logic low (output disabled)
Inhibit pin current ≤ –2 mA
• Referenced to input common
• Logic high (output enabled)
Open collector
Power Dissipation (Pd)
• 5 W
Output Power
• 15 watts
Lead Soldering Temperature (10 sec per lead)
• 300°C
Storage Temperature Range (Case)
• –65°C to +125°C
Output Voltage Temperature Coefficient
• 250 ppm/°C max
Input to Output Capacitance
• 100 p, typical
Current Limit
• 125% of full load typical
Isolation
• 100 megohm minimum at 500 V
Conversion Frequency
• 375 kHz. typical
Inhibit Pin Voltage (unit enabled)
• 5 to 6 V
RECOMMENDED OPERATING CONDITIONS
Input Voltage Range
• Continuous
Radiation (will operate through)
16 to 40 VDC MRH28XXS and MRH2812D
19 to 40 VDC MRH2815D
16 to 36 VDC MRH285XXT
13
• Neutron fluence 10 neutrons/ sq. cm.
11
• Radiation dose rate 10 rads (Si) /sec
5
• Total dose 10 rads (Si)
• 50 V for 50 msec transient
Case Operating Temperature (Tc)
• –55°C to +85°C full power
• –55°C to +125°C absolute
DERATING OUTPUT POWER/CURRENT AND INPUT VOLTAGE
Temperatures are referenced to the temperature at the converter’s baseplate
• Linearly derate output power/current from 100% at 85°C to 0% at 125°C.
• Above 105°C linearly derate steady state input voltage to 33 V and
transient voltage to 38 V, at 125°C.
• Operation below an input voltage of 19 volts, including operation in MIL-
STD-704E emergency power conditions, is possible with derated
output power. See Figures 9 and 10.
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, unless otherwise specified.
SINGLE OUTPUT MODELS
PARAMETER
MRH2805S
MRH2812S
TYP MAX
MRH2815S
TYP MAX
CONDITIONS
MIN
4.95
0.05
0.25
—
TYP
5.0
—
—
40
5
MAX
5.05
3.0
15
MIN
11.88
0.02
0.25
—
MIN
14.85
0.016
0.25
—
UNITS
VDC
A
OUTPUT VOLTAGE
OUTPUT CURRENT
OUTPUT POWER
OUTPUT RIPPLE
12
—
—
25
5
12.12
1.25
15
15
—
—
25
5
15.15
1.0
15
–55°C TO +85°C
MIN. TO MAX. V
W
IN
10 kHz TO 2 MHz
70
50
50
mV p-p
mV
LINE REGULATION
16 TO 40 V
IN
—
10
—
20
—
20
1
LOAD REGULATION
MIN. LOAD TO FULL
NO LOAD TO FULL
TRANSIENT 50 ms
NO LOAD
—
5
30
—
5
30
—
5
30
mV
2
INPUT VOLTAGE
16
28
—
50
—
22
40
16
28
—
50
—
22
40
19
28
—
50
—
22
40
VDC
V
—
50
—
50
—
50
INPUT CURRENT
—
60
—
60
—
60
FULL LOAD
—
750
25
—
730
25
—
720
25
mA
INHIBITED
—
—
—
INPUT RIPPLE
CURRENT
10 kHz TO10 MHz
—
73
—
—
—
25
75
5
50
—
—
—
10
—
76
—
—
—
25
78
5
50
—
—
—
10
—
78
—
—
—
25
80
5
50
—
—
—
10
mA p-p
%
EFFICIENCY
3
LOAD FAULT
SHORT CIRCUIT
OVERLOAD
DELAY
W
POWER DISSIPATION
START-UP
5
5
5
3
3
3
ms
Notes
1. Load regulation is not guaranteed below minimum load.
2. Converter should not be inhibited or operated below 12 Vin above 10
rads (Si) total dose.
3. Indefinite short circuit protection is not guaranteed above 85°C case.
4
B4-20
CRANE [ Crane Aerospace & Electronics. ]
