ROHM BP5275-25 Technical data

Data Sheet

Non-Isolated Step-Down 3-Terminal DC/DC Converters

BP5275-18 / BP5275-25 / BP5275-33 / BP5275-50

Description

The BP5275 series of DC/DC converters utilize a synchronous
rectification system.
A control circuit, switching element, and coil are built in, along
with input/output capacitors, resulting in stable operation with
no external components required.
High conversion efficiency, combined with an original heat
dissipation structure, enables configuration an ultra-compact
switching power supplies.
500mA output is possible with no heat sink required (800mA
with heat sink).
In addition, the ICs are pin-compatible with conventional
TO-220 LDO regulators, making replacement easy.
Low ripple voltage with high precision output ensure stable
operation against the fluctuating voltages from main power
supplies, making them ideal for use as local power supplies
(i.e. for microcontrollers).

Applications

Power supplies for copiers, personal computers,
facsimiles, AV equipment, measuring instruments,
vending machines, security device, registers,
industrial equipment, and maintenance tools

Features

1) No external parts required

2) High power conversion efficiency.

3) Heat sink unnecessary.

4) Low output ripple voltage

5) High output voltage accuracy

6) Pin-compatible with conventional 3-pin LDOs

7) Compact package.
BP5275-18 / BP5275-25 / BP5275-33 / BP5275-50 : SIP3

Dimensions (Unit : mm)

13.8 MAX

20.3

23.0 MAX

4.0±1.0

2.54±0.2
Pin No.1 2 3

4.2

5.2

5.2

2xC0.5

2.6

0.75

1.3

2.54±0.2

Note : Dimensions without tolerance is typical.

C0.5

0.5

List of the series

Input voltage

Output voltage

Maximum output current
(no heat sink / include heat sink)

Power conversion
efficiency (Vin=12V)

Absolute maximum ratings (Ta=25°C)

Parameter Symbol

Input voltage

Operating temperature range

Storage temperature range

Allowable maximum surface temperature

Maximum output current 1

Maximum output current 2

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© 2011 ROHM Co., Ltd. All rights reserved.

(with Heat Sink)

BP5275−18 BP5275−25 BP5275−33

4.5 to 14 4.5 to 14 5.0 to 14 V

1.8 2.5 3.3 V

500 / 800 500 / 800 500 / 800 mA

73 78 83 88

BP5275−18 BP5275−25 BP5275−33 BP5275−50

In V

V

Topr

Tstg

Tcmax

I

O1max

IO2max

15

−30 to 85

−40 to 105

100

500

800

15

−30 to 85

−40 to 105

100

500

800

BP5275−50

6.0 to 14

5.0

500 / 800

Limits

15

−30 to 85

−40 to 105

100

500

800

Unit

%

15

−30 to 85

−40 to 105

100

500

800

1/7

Unit

°C

°C

°C

°C

°C

2011.08 -

Rev. A

BP5275-18 / BP5275-25 / BP5275-33 / BP5275-50

Data Sheet

Block diagram

Control
Circuit

Electrical characteristics

BP5275−18 (Unless otherwise noted : Ta=25°C, Vin=12V, lo1=500mA)

Parameter Symbol Unit ConditionsMin. Typ. Max.

Input voltage

Output voltage

Output current 1

Output current 2

Line regulation

Load regulation

Output ripple voltage

Minimum start-up time

Conversion efficiency

Operation frequency

1 Derating required according to the input voltage and ambient temperature.

Vin 4

V

O V

1.75

I

O1

I

O2

Vr

Vl

Vp

Ts



f MHz1.5

0

0







4

65



12

1.80





5

10

5

7

73

14

1.85

500

800

50

50

80





Measurement circuit

Vin

Vin

V

mA

mA

mV

mV

mV

msec

%

GND

DC

O1=0mA

I

With heat sink

Vin=4 to 14V

O=0 to 500mA

I

P-P

Vin=0V 3V,Ro=3.6Ω

1 2 3

Io

AA

V

VV

1

1

Vout

GND

BP5275-25 (Unless otherwise noted : Ta=25°C, Vin=12V, lo1=500mA)

Parameter Symbol Unit ConditionsMin. Typ. Max.

Input voltage

Output voltage

Output current 1

Output current 2

Line regulation

Load regulation

Output ripple voltage

Minimum start-up time

Conversion efficiency

Operation frequency

1 Derating required according to the input voltage and ambient temperature.

Vin 4

V

O V

2.45

I

O1

I

O2

Vr

Vl

Vp

Ts



f MHz1.5

0

0







4

73



12

2.50





5

10

5

7

78

14

2.55

500

800

50

50

50





V

mA

mA

mV

mV

mV

msec

%

DC

O1=0mA

I

With heat sink

Vin=4 to 14V

O1=0 to 500mA

I

P-P

Vin=3V 4V,Ro=5Ω

1

1

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© 2011 ROHM Co., Ltd. All rights reserved.

2/7

2011.08 -

Rev. A

BP5275-18 / BP5275-25 / BP5275-33 / BP5275-50

Electrical characteristics

BP5275−33 (Unless otherwise noted :Ta=25°C, Vin=12V, lo1=500mA)

Parameter Symbol Unit ConditionsMin. Typ. Max.

Input voltage

Output voltage

Output current 1

Output current 2

Line regulation

Load regulation

Output ripple voltage

Minimum start-up time

Conversion efficiency

Operation frequency

1 Derating required according to the input voltage and ambient temperature.

Vin 4.5

V

O V

3.23

I

O1

I

O2

Vr

Vl

Vp

Ts



f MHz1.5

0

0







4

78



12

3.30





5

10

5

7

83

BP5275-50 (Unless otherwise noted : Ta=25°C, Vin=12V, lo1=500mA)

Parameter Symbol Unit ConditionsMin. Typ. Max.

Input voltage

Output voltage

Output current 1

Output current 2

Line regulation

Load regulation

Output ripple voltage

Minimum start-up time

Conversion efficiency

Operation frequency

1 Derating required according to the input voltage and ambient temperature.

Vin 6

V

O V

I

O1

I

O2

Vr

Vl

Vp

Ts



f MHz1.5

4.9

0

0







4

83



12

5.0





5

10

5

7

88

14

3.37

500

800

50

50

50





14

5.1

500

800

50

50

50





V

mA

mA

mV

mV

mV

msec

%

V

mA

mA

mV

mV

mV

msec

%

DC

O1=0mA

I

With heat sink

Vin=4.5 to 14V

O=0 to 500mA

I

P-P

Vin=3V 4.5V,Ro=6.6Ω

DC

O1=0mA

I

With heat sink

Vin=6 to 14V

O1=0 to 500mA

I

P-P

Vin=3V 6V,Ro=10Ω

Data Sheet

1

1

1

1

●OPERATION NOTES
・

This module will stop outputting because of protection circuit when the input voltage becomes maximum input voltage or less.

Please note that the input voltage must not become maximum input voltage in any state of the load.

・After the circuit starts, the output voltage needs to become the fixed voltage within minimum activation time.

If the output voltage is below the fixed voltage after the minimum activation time, it doesn’t work because of the protection circuit.

Please evaluate sufficiently about activation characteristics of input voltage and load characteristics when starting.

・When the output circuit shorts, short-circuit protection of timer-latch type will work and stop outputting.

To release the protection, it is necessary to turn on the switch again.

This product also has protection element for safety. The protection element is fused if the current, with which the protection

element will fuse, will be input by the time the short-circuit protection of timer-latch hangs.

Please evaluate sufficiently at using environment about the action when the output circuit shorts.

・There are some case that the heat generates at the module by exceeding allowable maximum surface temperature when the

load current which exceeds the maximum output current is electrified.

Please make design keeping enough margins not to exceed allowable maximum surface temperature at any time under any

application or any test conditions.

・The heat sink at back parts of the product is connected to GND. Please mind the arrangement not to contact with

surrounding parts.

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© 2011 ROHM Co., Ltd. All rights reserved.

3/7

2011.08 -

Rev. A