SMHF SERIES
SINGLE AND DUAL
15 WATT
DC/DC CONVERTERS
ABSOLUTE MAXIMUM RATINGS
SYNC AND INHIBIT
TYPICAL CHARACTERISTICS
Input Voltage
• 16 to 40 VDC
Power Dissipation (Pd)
• 8 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
Sync In (500 to 600 kHz)
• Duty cycle 40% to 60%
• Logic low 0.8 V max
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
• 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 max
Inhibit pin current 4.0 mA max
• Referenced to input common
• Logic high (output enabled)
Open collector or unconnected
RECOMMENDED OPERATING CONDITIONS
• 50 dB typical
Input Voltage Range
• 16 to 40 VDC continuous
• 0 V for up to 50 msec transient
Case Operating Temperature (Tc)
• –55°C to +125°C full power
Conversion Frequency (º55°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
• –55°C to +135°C absolute
Derating Output Power/Current (Tc)
• Linearly from 100% at 125°C to 0% at 135°C
Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, radiation level O, unless otherwise specified.
SINGLE OUTPUT MODELS
SMHF283R3S
SMHF2805S
SMHF2812S
SMHF2815S
OUTPUT VOLTAGE
Tc = 25°C
3.27 3.3 3.33 4.95
5
5.05 11.88 12 12.12 14.85 15 15.15
VDC
A
OUTPUT CURRENT
V
V
= 16 TO 40 VDC
—
0
—
—
2.4
8
—
0
—
2.4
12
80
—
0
—
—
1.25
15
—
0
—
—
60
1.00
15
IN
OUTPUT POWER
= 16 TO 40 VDC
—
W
IN
OUTPUT RIPPLE
VOLTAGE
LINE REGULATION
10 kHz - 2 MHz
Tc = –55°C TO +125°C
= 16 TO 40 VDC
—
—
—
60
80
5
160
240
100
—
—
—
30
—
—
—
60
50
5
160
120
100
—
—
—
75
mV p-p
mV
150 240
5
100 260
V
100
5
100
IN
LOAD REGULATION
INPUT VOLTAGE
NO LOAD TO FULL
INPUT CURRENT
NO LOAD TO FULL
CONTINUOUS
TRANSIENT 120 ms
NO LOAD
—
16
0
20
28
—
25
—
5
45
—
73
50
40
—
16
0
20
28
—
25
50
40
50
40
—
16
0
20
28
—
25
50
40
50
50
—
16
0
20
28
—
25
50
40
50
62
mV
VDC
V
50
—
—
—
—
—
70
65
—
—
—
—
—
73
—
—
—
—
—
78
—
—
—
—
—
74
FULL LOAD
397
12
80
120
—
560 624
680 752
670 752
mA
INHIBITED
5
12
80
120
—
5
12
80
120
—
5
12
80
120
—
INPUT RIPPLE
CURRENT
10k Hz - 10 MHz
Tc = –55°C TO +125°C
Tc = 25°C
35
—
75
35
—
79
35
—
80
mA p-p
%
EFFICIENCY
1
LOAD FAULT
SHORT CIRCUIT
POWER DISSIPATION
—
—
5
8
—
—
3.5
7.5
8
—
—
3.5
7.5
8
—
—
3.5
7.5
7
W
2
RECOVERY
7.5
30
30
30
30
ms
STEP LOAD
RESPONSE
50 %–100%– 50%
TRANSIENT
–400 150 500 –500 150 500 –700 150 700 –800 200 800
150 300 150 300 150 500 600 1200
mV pk
µs
2
RECOVERY
—
—
—
—
STEP LINE
RESPONSE
16 TO 40 TO 16 V
IN
3
TRANSIENT
–800 550 800 –800 550 800 –800 550 800 –800 550 800
mV pk
µs
µs
2
RECOVERY
—
—
—
0.8
10
1.2
25
—
—
—
0.8
10
1.2
25
—
—
—
0.8
10
1.2
25
—
—
—
0.8 1.2
10 25
200 1500
START-UP
DELAY
4
0 TO 28 VIN
OVERSHOOT
200 300
100 600
200 1200
mV pk
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 >10µs.
4. Input step transition time <100µs.
34
CRANE [ Crane Aerospace & Electronics. ]
