BH□□NB1WHFV Series

Technical Note

5/8

www.rohm.com

2009.04 - Rev.A

© 2009 ROHM Co., Ltd. All rights reserved.



Block diagram, recommended circuit diagram, and pin assignment diagram

Pin

No.

Symbol

Function

1

STBY

Output voltage on/off control

(High: ON, Low: OFF)

2

GND

Ground

3

Power supply input

4

Voltage output

5

N.C.

NO CONNECT



Power dissipation (Pd)

1. Power dissipation (Pd)

Power dissipation calculations include estimates of power dissipation characteristics and internal IC power consumption,

and should be treated as guidelines. In the event that the IC is used in an environment where this power dissipation is

exceeded, the attendant rise in the junction temperature will trigger the thermal shutdown circuit, reducing the current

capacity and otherwise degrading the IC's design performance. Allow for sufficient margins so that this power dissipation is

not exceeded during IC operation.

2. Power dissipation/power dissipation reduction (Pd)

HVSOF5

*Circuit design should allow a sufficient margin for the temperature range so that PMAX < Pd.



Input Output capacitors

It is recommended to insert bypass capacitors between input and GND pins, positioning them as close to the pins as

possible. These capacitors will be used when the power supply impedance increases or when long wiring paths are used, so

they should be checked once the IC has been mounted.

Ceramic capacitors generally have temperature and DC bias characteristics. When selecting ceramic capacitors, use X5R or

X7R, or better models that offer good temperature and DC bias characteristics and high tolerant voltages.

Typical ceramic capacitor characteristics

0

20

40

60

80

100

120

0

123

4

DC bias Vdc[V]

70

75

80

85

90

95

100

01

2

3

4

DC bias Vdc[V]

0

20

40

60

80

100

120

-25

0

25

50

75

Temp[℃]

50 V

tolerance

16 V tolerance

10 V

tolerance

50 V tolerance

16 V tolerance

10 V

tolerance

Y5V

X7R

X5R

Fig. 27 Capacitance vs Bias

(Y5V)

Fig. 28 Capacitance vs Bias

(X5R, X7R)

Fig. 29 Capacitance vs Temperature

(X5R, X7R, Y5V)

0

0.2

0.4

0.6

0

25

50

75

100

125

Ta[℃]

Board: 70 mm

 70 mm  1.6 mm

Material: Glass epoxy PCB

410 mW

Fig. 26 HVSOF5 Power Dissipation/Power Dissipation Reduction (Example)

THERMAL

PROTECTION

OVER CURRENT

PROTECTION

VOLTAGE

REFERENCE

CONTROL

BLOCK

VOUT

N.C.

VIN

VIN

Cin

GND

STBY

VSTB

VOUT

Co

3

2

1

5

4

Cin    0.1

F

Co    2.2

F

BH□□NB1WHFV

Fig. 25