OKI-78SR3.3/1.5-W36-C - MURATA MANUFACTURING

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MDC_OKI-78SR-W36.C05 Page 1 of 20

OKI-78SR Series

Non-Isolated Switching Regulator DC-DC

Typical units

FEATURES

7-36Vin (3.3 & 5Vout), 15-36Vin (12Vout)



Fixed Output: 3.3 or 5V @ 1.5A or 12V @ 1.0A

PRODUCT OVERVIEW

Vertical SIP or horizontal mount, small footprint

package

“No heat sink” direct replacement for 3-terminal

78xx-series linear regulators

High efﬁciency with no external components

Short circuit protection

Outstanding thermal derating performance

UL/EN/IEC 60950-1, 2nd Edition safety approvals

Fabricated on a 0.41 x 0.65 inch (10.4 x 16.5

mm) Single Inline Package (SIP) module, the OKI-

78SR series are non-isolated switching regulator

(SR) DC-DC power converters for embedded ap-

plications. The ﬁxed single output converters offer

both tight regulation and high efﬁciency directly at

the power usage site and are a direct plug-in

replacement for TO-220 package 78xx series

linear regulators. Typically, no extra outside

components are required.

Three nominal output voltages are offered (3.3,

5 and 12 VDC), up to 1.5 Amp maximum output.

Based on ﬁxed-frequency buck switching

topology, the high efﬁciency means very low heat

and little electrical noise, requiring no external

components. The 3.3 and 5Vout models have an

ultra wide input range of 7 to 36 Volts DC and the

12Vout model has an input voltage range of 15 to

36V.

Protection features include short circuit current

limit protection. The OKI-78SR is designed to

meet all standards approvals. RoHS-6 (no lead)

hazardous material compliance is speciﬁed as

standard.

For full details go to

www.murata-ps.com/rohs

Connection Diagram

Figure 1. OKI-78SR

Note: Murata Power Solutions strongly recommends an external input fuse, F1.

See speciﬁcations.

External

Power

Source

Controller

+Vin

+Vout

Reference

and

Error Ampliﬁer

Common

New!

12V

Model

• Switching

• Filters

• Current Sense

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MDC_OKI-78SR-W36.C05 Page 2 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

Note:

Some model number combinations

may not be available.

Contact Murata Power Solutions.

PART NUMBER STRUCTURE

OKI - / 1.5 - W36 H - C RoHS-6 Hazardous

Substance Compliance

Okami Non-Isolated PoL

78SR Series Blank: Vertical Mount

H Sufﬁx: Horizontal Mount

Maximum Rated Output in Volts

Input Voltage Range

7-36V (3.3 & 5Vo)

Maximum Rated Output 15-36V (12Vo)

Current in Amps

FUNCTIONAL SPECIFICATIONS SUMMARY AND ORDERING GUIDE

Root Model

Output Input

Efficiency

Package

Inches (mm)

OUT

(Volts)

OUT

(Amps

max)

Power

(Watts)

R/N (mVp-p) Regulation (Typ.)

Nom.

(Volts)

Range

(Volts)

no load

(mA)

full load

(Amps)

Max. Line Load Min. Typ.

OKI-78SR-3.3/1.5-W36-C

3.3 1.5 4.95 40 ±0.25% ±0.40% 12 7-36 5 0.48 84% 85.5%

0.41 x 0.34 x 0.65

(10.4 x 8.64 x 16.5)

OKI-78SR-5/1.5-W36-C 5 1.5 7.5 75 ±0.25% ±0.40% 12 7-36 5 0.69 89% 90.5%

0.41 x 0.34 x 0.65

(10.4 x 8.64 x 16.5)

OKI-78SR-12/1.0-W36-C

12 1.0 12 75 ±0.25% ±0.25% 24 15-36 5 0.53 93.5% 95.3%

0.41 x 0.34 x 0.65

(10.4 x 8.64 x 16.5)

NOTE: All specifications are at nominal line voltage, Vout = nominal and full load, +25˚C.with no external capacitor, unless otherwise noted.

Product Label

Because of the small size of these products, the product label contains a

character-reduced code to indicate the model number and manufacturing date

code. Not all items on the label are always used. Please note that the label dif-

fers from the product photograph on page 1. Here is the layout of the label:

The label contains three rows of information:

Mfg. XXXXXX Product code

date

code

YMDX Rev. Revision level

The manufacturing date code is four characters:

First character – Last digit of manufacturing year, example 2009

Second character – Month code (1 through 9 = Jan-Sep;

Figure 2. Label Artwork Layout

First row – Murata Power Solutions logo

Second row – Model number product code (see table)

Third row – Manufacturing date code and revision level

O, N, D = Oct, Nov, Dec)

Third character – Day code (1 through 9 = 1 to 9, 10 = 0 and

11 through 31 = A through Z)

Fourth character – Manufacturing information

78SR - 3.3

Model Number Product

Code

OKI-78SR-3.3/1.5-W36-C I33115

OKI-78SR-5/1.5-W36-C I50115

OKI-78SR-12/1.0-W36-C I12110

OKI-78SR-3.3/1.5-W36H-C I33115H

OKI-78SR-5/1.5-W36H-C I50115H

OKI-78SR-12/1.0-W36H-C I12110H

NEW

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MDC_OKI-78SR-W36.C05 Page 3 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

FUNCTIONAL SPECIFICATIONS – OKI-78SR-3.3/1.5-W36-C

ABSOLUTE MAXIMUM RATINGS

Conditions ①

Minimum Typical/Nominal Maximum Units

Input

Voltage,

Continuous

Full power operation 0 36 Vdc

Input Reverse

Polarity

None, install external fuse None Vdc

Output

Power

0 5.15 W

Output Current

Current-limited, no damage, short-circuit protected 0 1.5 A

Storage

Temperature

Range

Vin = Zero (no power) -55 125 °C

Absolute maximums are stress ratings. Exposure of devices to greater than any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those

listed in the Performance/Functional Speciﬁcations Table is not implied or recommended.

INPUT

Operating voltage range

7 12 36 Vdc

Recommended External Fuse

Fast blow 2 A

Reverse Polarity Protection ⑨

None, install external fuse None Vdc

Internal Filter

Type

C-TYPE

Input current

Full Load

Conditions

Vin = nominal 0.48 0.51 A

Low Line

Vin @ min 0.80 0.85 A

Inrush

Transient

0.16 A

-Sec.

Short Circuit Input Current

5 mA

No Load Input Current

Vin = nominal 5 10 mA

Shut

Down Mode Input Current

1 mA

Reﬂected (back) ripple current ②

(Cin = 2 X 100uF, CBus = 1000uF, LBus = 1uH) 50 mA, pk-pk

GENERAL

and

SAFETY

Efficiency @ Vin nom, 3.3Vout 83.7 85.5 %

@ Vin min, 3.3Vout 87.0 88.4 %

Safety Certiﬁed to UL-60950-1, IEC/EN60950-1,

2nd Edition Yes

Calculated MTBF ④

Per Telcordia SR332, issue 1, class 3, ground

ﬁxed, Tambient=+25°C 78.7 Hours x 10

DYNAMIC

CHARACTERISTICS

Fixed Switching

Frequency

500 kHz

Dynamic Load Response 50-100-50% load step, settling time to within

±2% of Vout di/dt =1A/μSec 25 50 μSec

Dynamic Load

Peak

Deviation

same as above 100 150 mV

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MDC_OKI-78SR-W36.C05 Page 4 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

FUNCTIONAL SPECIFICATIONS – OKI-78SR-3.3/1.5-W36-C (CONT.)

OUTPUT

Conditions

Minimum Typical/Nominal Maximum Units

Total

Output

Power

0 4.95 5.15 W

Voltage

Nominal Output

Voltage

Range

3.168

3.3

3.432 Vdc

Setting

Accuracy

At 50% load -4 4 % of Vnom.

Output

Voltage

Overshoot

Startup:

3 %Vo nom

Current

Output Current Range

0 1.5 1.5 A

Minimum Load ⑪

No minimum load

Current Limit Inception 98% of Vnom., after warmup @3.3Vout 2.50 3.50 5.00 A

Short Circuit Mode ⑥⑪

Short Circuit Current

Hiccup technique, autorecovery within

±1% of Vout 0.01 A

Short Circuit Duration

(remove short for recovery) Output shorted to ground, no damage Continuous

Short circuit protection method ⑧

Current limiting

Regulation ⑩

Total

Regulation Band

Over all line, load and temp conditions -3 Vo set 3 % Vo set

Line Regulation

Vin=min. to max. Vout=nom. ±0.25 %

Load Regulation

Iout=min. to max. ±0.40 %

Ripple and Noise (20MHz BW) ⑪

3.3Vo, 12Vin

40 mV pk-pk

Temperature

Coefﬁcient

At all outputs ±0.02 % of Vnom./°C

Maximum Capacitive Loading

low ESR; >0.001, <0.01 ohm 300 μF

Maximum Capacitive Loading

0.01 ohm 3300 μF

MECHANICAL

Outline Dimensions

0.41 x 0.65 x 0.34

Inches

10.4 x 16.5 x 8.64

Weight

0.07 Ounces

2 Grams

Pin Material

copper alloy

Pin Finish

Matte Tin 100-300 μ"

Nickel 75-150 μ"

ENVIRONMENTAL

Operating Ambient Temperature Range ③

see derating curves -40 85 °C

Storage

Temperature

Vin = Zero (no power) -55 125 °C

RoHS Compliant

RoHS

Specification Notes

1) All speciﬁcations are typical unless noted. General conditions for Speciﬁcations are +25 deg.C ambient

temperature, Vin=nominal, Vout=nominal, full rated load. Adequate airﬂow must be supplied for extended

testing under power. See Derating curves..

2) Input Back Ripple Current is tested and speciﬁed over a 5 Hz to 20 MHz bandwidth. Input ﬁltering is Cin=2

x 100 μF, Cbus=1000 μF, Lbus=1 μH. All caps are low ESR types.

3) Note that Maximum Power Derating curves indicate an average current at nominal input voltage. At higher

temperatures and/or lower airﬂow, the DC/DC converter will tolerate brief full current outputs if the total

RMS current over time does not exceed the Derating curve. All Derating curves are presented near sea

level altitude. Be aware of reduced power dissipation with increasing altitude.

4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1, Case 3, ground

ﬁxed conditions, Tpcboard=+25 ˚C, full output load, natural air convection.

5) The input and output are not isolated. They share a single COMMON power and signal return.

6) Short circuit shutdown begins when the output voltage degrades approximately 2% from the selected

setting. Output current limit and short circuit protection are non-latching. When the overcurrent fault is

removed, the converter will immediately recover.

7) The output is not intended to sink appreciable reverse current.

8) “Hiccup” overcurrent operation repeatedly attempts to restart the converter with a brief, full-current

output. If the overcurrent condition still exists, the restart current will be removed and then tried again.

This short current pulse prevents overheating and damaging the converter.

9) Input Fusing: If reverse polarity is accidentally applied to the input, to ensure reverse input protection,

always connect an external input fast-blow fuse in series with the +Vin input. Use approximately twice the

full input current rating with nominal input voltage.

10) Regulation speciﬁcations describe the deviation as the line input voltage or output load current is varied

from a nominal midpoint value to either extreme.

11) Output noise may be further reduced by installing an external ﬁlter. Do not exceed the maximum output

capacitance. At zero output current and no external capacitor, the output may contain low frequency

components which exceed the ripple speciﬁcation. The output may be operated indeﬁnitely with no load.

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MDC_OKI-78SR-W36.C05 Page 5 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

= 36V

Efﬁciency vs. Line Voltage and Load Current @ +25˚C. (Vout = Vnom.) Maximum Current Temperature Derating at sea level (Vin=7V to 36V)

100 2.00

50 1.00

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Load Current (Amps)

0.00

25 30 35

40 45 50

55 60 65 70 75 80

Ambient Temperature (ºC)

0.33 m/s (65

LFM)

PERFORMANCE DATA – OKI-78SR-3.3/1.5-W36-C

Efficiency (%)

Output Current (Amps)

Output Ripple and Noise (Vin=7V, Vout=nominal, Iout=1.5A, Cload=0, Ta=+25˚C.,

ScopeBW=100MHz)

Output Ripple and Noise (Vin=12V, Vout=nominal, Iout=1.5A, Cload=0, Ta=+25˚C.,

ScopeBW=100MHz)

Output Ripple and Noise (Vin=36V, Vout=nominal, Iout=1.5A, Cload=0, Ta=+25˚C.,

ScopeBW=100MHz)

= 12V

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MDC_OKI-78SR-W36.C05 Page 6 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

PERFORMANCE DATA – OKI-78SR-3.3/1.5-W36-C

Step Load Transient Response (Vin=7V, Vout=nominal, Cload=0, Iout=0.75A to 1.5A,

Slew=1A/μS, Ta=+25˚C.) Trace 2=Vout, 100 mV/div. Trace 4=Iout, 0.5A/div

Step Load Transient Response (Vin=7V, Vout=nominal, Cload=0, Iout=1.5A to 0.75A,

Slew=1A/μS, Ta=+25˚C.) Trace 2=Vout, 100 mV/div. Trace 4=Iout, 0.5A/div.

Step Load Transient Response (Vin=12V, Vout=nominal, Cload=0, Iout=0.75A to 1.5A,

Slew=1A/μS, Ta=+25˚C.) Trace 2=Vout, 100 mV/div. Trace 4=Iout, 0.5A/div.

Step Load Transient Response (Vin=12V, Vout=nominal, Cload=0, Iout=1.5A to 0.75A,

Slew=1A/μS, Ta=+25˚C.) Trace 2=Vout, 100 mV/div. Trace 4=Iout, 0.5A/div.

Step Load Transient Response (Vin=36V, Vout=nominal, Cload=0, Iout=0.75A to 1.5A,

Slew=1A/μS, Ta=+25˚C.) Trace 2=Vout, 100 mV/div. Trace 4=Iout, 0.5A/div.

Step Load Transient Response (Vin=36V, Vout=nominal, Cload=0, Iout=1.5A to 0.75A,

Slew=1A/μS, Ta=+25˚C.) Trace 2=Vout, 100 mV/div. Trace 4=Iout, 0.5A/div.

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MDC_OKI-78SR-W36.C05 Page 7 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

FUNCTIONAL SPECIFICATIONS – OKI-78SR-5/1.5-W36-C

ABSOLUTE MAXIMUM RATINGS

Conditions ①

Minimum Typical/Nominal Maximum Units

Input

Voltage,

Continuous

Full power operation 0 36 Vdc

Input Reverse

Polarity

None, install external fuse None Vdc

Output

Power

0 7.80 W

Output Current

Current-limited, no damage, short-circuit protected 0 1.5 A

Storage

Temperature

Range

Vin = Zero (no power) -55 125 °C

Absolute maximums are stress ratings. Exposure of devices to greater than any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those

listed in the Performance/Functional Speciﬁcations Table is not implied or recommended.

INPUT

Operating voltage range

7 12 36 Vdc

Recommended External Fuse

Fast blow 2 A

Reverse Polarity Protection ⑨

None, install external fuse None Vdc

Internal Filter

Type

C-TYPE

Input current

Full Load Conditions

Vin = nominal 0.69 0.73 A

Low Line

Vin @ min 1.16 1.22 A

Inrush

Transient

0.16 A

-Sec.

Short Circuit Input Current

5 mA

No Load Input Current

Vin = nominal 5 10 mA

Shut

Down Mode Input Current

1 mA

Reﬂected (back) ripple current ②

(Cin = 2 X 100uF, CBus = 1000uF, LBus = 1uH) 15 mA, pk-pk

GENERAL

and

SAFETY

Efficiency @ Vin nom, 5Vout 89.0 90.5 %

@ Vin min, 5Vout 91.4 92.5 %

Safety Certiﬁed to UL-60950-1, IEC/EN60950-1,

2nd Edition Yes

Calculated MTBF ④

Per Telcordia SR332, issue 1, class 3, ground

ﬁxed, Tambient=+25°C 78.7 Hours x 10

DYNAMIC

CHARACTERISTICS

Fixed Switching

Frequency

500 kHz

Dynamic Load Response 50-100-50% load step, settling time to within

±2% of Vout di/dt =1A/μSec 50 75 μSec

Dynamic Load

Peak

Deviation

same as above 150 200 mV

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MDC_OKI-78SR-W36.C05 Page 8 of 20

OKI

78SR Series

Non-Isolated Switching Regulator DC-

FUNCTIONAL SPECIFICATIONS – OKI-78SR-5/1.5-W36-C (CONT.)

OUTPUT

Conditions

Minimum Typical/Nominal Maximum Units

Total

Output

Power

0 7.5 7.8 W

Voltage

Nominal Output

Voltage

Range

4.8

5.0

5.2 Vdc

Setting

Accuracy

At 50% load -4 4 % of Vnom.

Output

Voltage

Overshoot

Startup:

3 %Vo nom

Current

Output Current Range

0 1.5 1.5 A

Minimum Load ⑪

No minimum load

Current Limit Inception 98% of Vnom., after warmup @5Vout 2.50 3.50 5.00 A

Short Circuit Mode ⑥⑪

Short Circuit Current

Hiccup technique, autorecovery within

±1% of Vout 0.01 A

Short Circuit Duration

(remove short for recovery) Output shorted to ground, no damage Continuous

Short circuit protection method ⑧

Current limiting

Regulation ⑩

Total

Regulation Band

Over all line, load and temp conditions -3 Vo set 3 % Vo set

Line Regulation

Vin=min. to max. Vout=nom. ±0.25 %

Load Regulation

Iout=min. to max. ±0.40 %

Ripple and Noise (20MHz BW) ⑪

5Vo, 12Vin

75 mV pk-pk