RECOMMENDED OPERATING CONDITIONS

TYPICAL CHARACTERISTICS

SYNC AND INHIBIT

ABSOLUTE MAXIMUM RATINGS

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

34

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 (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

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

• –55°C to +135°C absolute

Derating Output Power/Current (Tc)

• Linearly from 100% at 125°C to 0% at 135°C

SMHF SERIES

SINGLE AND DUAL

15 WATT

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

OUTPUT CURRENT

—

—

2.4

—

—

2.4

—

—

1.25

—

—

1.00

A

OUTPUT POWER

0

—

8

0

—

12

0

—

15

0

—

15

W

OUTPUT RIPPLE

10 kHz - 2 MHz

—

60

160

—

30

80

—

60

160

—

60

75

mV p-p

VOLTAGE

Tc = –55°C TO +125°C

—

80

240

—

150

240

—

50

120

—

100

260

LINE REGULATION

—

5

100

—

5

100

—

5

100

—

5

100

mV

LOAD REGULATION

NO LOAD TO FULL

—

20

50

—

20

50

—

20

50

—

20

50

mV

INPUT VOLTAGE

CONTINUOUS

16

28

40

16

28

40

16

28

40

16

28

40

VDC

NO LOAD TO FULL

TRANSIENT 120 ms

0

—

50

0

—

50

0

—

50

0

—

50

V

INPUT CURRENT

NO LOAD

—

25

65

—

25

40

—

25

50

—

25

62

FULL LOAD

—

—

397

—

560

624

—

680

752

—

670

752

mA

INHIBITED

—

5

12

—

5

12

—

5

12

—

5

12

INPUT RIPPLE

10k Hz - 10 MHz

—

45

80

—

35

80

—

35

80

—

35

80

mA p-p

CURRENT

Tc = –55°C TO +125°C

—

—

120

—

—

120

—

—

120

—

—

120

EFFICIENCY

Tc = 25°C

70

73

—

73

75

—

78

79

—

74

80

—

%

SHORT CIRCUIT

POWER DISSIPATION

—

5

8

—

3.5

8

—

3.5

8

—

3.5

7

W

—

7.5

30

—

7.5

30

—

7.5

30

—

7.5

30

ms

STEP LOAD

50 %–100%– 50%

RESPONSE

TRANSIENT

–400

150

500

–500

150

500

–700

150

700

–800

200

800

mV pk

—

150

300

—

150

300

—

150

500

—

600

1200

µs

STEP LINE

RESPONSE

–800

550

800

–800

550

800

–800

550

800

–800

550

800

mV pk

—

0.8

1.2

—

0.8

1.2

—

0.8

1.2

—

0.8

1.2

µs

START-UP

DELAY

—

10

25

—

10

25

—

10

25

—

10

25

µs

0 TO 28 VIN

—

200

300

—

100

600

—

200

1200

—

200

1500

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.

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 max

Inhibit pin current 4.0 mA max

• Referenced to input common

• Logic high (output enabled)

Open collector or unconnected

Electrical Characteristics: 25°C Tc, 28 VDC Vin, 100% load, radiation level O, unless otherwise specified.