MHD SERIES
20 WATT
ABSOLUTE MAXIMUM RATINGS
Input Voltage
• 16 to 40 V
Output Power
• 15 to 20 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 AND INHIBIT
Sync (500 to 675 kHz)
• Duty cycle 40% min, 60% max
• Logic low 0.8 V max, 0.0 V min
• Logic high 4.0 V min, 10 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 8.0 mA max
• Referenced to input common
• Logic high (output enabled)
Open collector
TYPICAL CHARACTERISTICS
Output Voltage Temperature Coefficient
• 100 ppm/°C typical
Input to Output Capacitance
• 50 pF typical
Current Limit
• 115% of full load typical
Isolation
• 100 megohm minimum at 500 V
Audio Rejection
• 50 dB typical
Conversion Frequency
• Free run mode 625 kHz typical
550 kHz. min, 650 kHz max
• External sync range 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 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
• Linearly from 100% at 125°C to 0% at 135° C
Electrical Characteristics:25C Tc, 28 VDC Vin, 100% load, free run, 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
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
1
FULL LOAD
INHIBITED
1
10 kHz – 10 MHz
Tc = –55°C TO +125°C
SHORT CIRCUIT
POWER DISSIPATION
RECOVERY
1, 3
50% – 100% – 50%
10% – 100%
100% – 10%
50% – 100% – 50%
10% – 100%
100% – 10%
16 – 40 – 16 VDC
TRANSIENT
5
RECOVERY
4
START-UP
1
DELAY
OVERSHOOT
FULL LOAD
NO LOAD
MHD2805S
MIN
4.95
0
0
—
—
—
—
—
—
16
—
—
—
—
—
76
—
—
—
—
—
—
—
—
—
—
—
—
—
TYP MAX
5.00 5.05
—
3
—
35
50
10
15
5
15
28
—
35
0.70
7
20
78
—
1.4
±200
–400
+350
60
60
200
15
50
90
50
50
50
50
40
50
75
—
8
50
—
10
5
±300
–600
+600
200
600
600
MHD2812S
MIN TYP MAX
11.88 12.00 12.12
0
— 1.67
0
—
—
—
—
—
—
16
—
—
—
—
—
80
—
—
—
—
—
—
—
—
—
—
—
—
—
—
25
40
10
15
5
15
28
—
35
0.87
7
20
83
—
1.4
±250
–600
+500
60
150
250
20
40
90
50
50
50
50
40
50
75
—
8
50
—
10
5
±400
–1000
+750
200
300
500
MHD2815S
MIN TYP MAX
14.85 15.00 15.15
0
— 1.33
0
—
—
—
—
—
—
16
—
—
—
—
—
81
—
—
—
—
—
—
—
—
—
—
—
—
—
—
25
40
10
15
5
15
28
—
35
0.85
7
20
84
—
1.4
±350
–800
+600
60
250
250
20
40
90
50
50
50
50
40
50
75
—
8
50
—
10
5
±500
–1200
+1000
200
500
500
MHD2818S
MIN TYP MAX
17.82 18.00 18.18
0
— 1.11
0
—
—
—
—
—
—
16
—
—
—
—
—
81
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
28
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
20
40
90
50
50
50
50
40
50
75
—
8
50
—
10
5
±600
—
—
200
—
—
±600
300
5
180
—
UNITS
VDC
A
W
mV p
mV
mV
VDC
V
mA
A
mA
mA p-p
%
A
ms
mV pk
INPUT RIPPLE
CURRENT
EFFICIENCY
LOAD FAULT
3
SHORT CIRCUIT TO
FULL LOAD
STEP LOAD RESP.
TRANSIENT
RECOVERY
4
STEP LINE RESP.
µs
±200 ±300
—
300
1.4
0
50
5
50
250
±400 ±500
—
300
1.4
0
120
5
120
600
±500 ±600
—
300
1.4
0
150
5
150
750
mV pk
µs
ms
mV pk
Notes
1. Tc = –55°C to +125°C
2. Operation is limited below 16V (see Figure 15).
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.
B2-48
CRANE [ Crane Aerospace & Electronics. ]
