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TSZ02201-0RBR0A300050-1-2

TSZ22111･15･001

8/9

7.FEB.2013.Rev.001

BUxxTD2WNVX series

Datasheet

About power dissipation (Pd)

As for power dissipation, an approximate estimate of the heat reduction characteristics and internal power consumption of

IC are shown, so please use these for reference. Since power dissipation changes substantially depending on the

implementation conditions (board size, board thickness, metal wiring rate, number of layers and through holes, etc.), it is

recommended to measure Pd on a set board. Exceeding the power dissipation of IC may lead to deterioration of the

original IC performance, such as causing operation of the thermal shutdown circuit or reduction in current capability.

Therefore, be sure to prepare sufficient margin within power dissipation for usage.

Calculation of the maximum internal power consumption of IC (PMAX)

PMAX=(VIN-VOUT)×IOUT(MAX.) (VIN: Input voltage

VOUT: Output voltage

IOUT(MAX): Maximum output current)

Measurement conditions

Standard ROHM Board

Evaluation Board 1

Top Layer (Top View)

Top Layer (Top View)

Layout of Board for

Measurement

IC

Implementation

Position

Bottom Layer (Top View)

Bottom Layer (Top View)

Measurement State

With board implemented (Wind speed 0 m/s)

With board implemented (Wind speed 0 m/s)

Board Material

Glass epoxy resin (Double-side board)

Glass epoxy resin (Double-side board)

Board Size

70 mm x 70 mm x 1.6 mm

40 mm x 40 mm x 1.6 mm

Top layer

Metal (GND) wiring rate: Approx. 0%

Metal (GND) wiring rate: Approx. 50%

Wiring

Rate

Bottom

layer

Metal (GND) wiring rate: Approx. 50%

Metal (GND) wiring rate: Approx. 50%

Through Hole

Diameter 0.5mm x 6 holes

Diameter 0.5mm x 25 holes

Power Dissipation

0.56W

0.39W

Thermal Resistance

θja=178.6°C/W

θja=256.4°C/W

* Please design the margin so that

PMAX becomes is than Pd (PMAX

<Pd)

within the usage temperature range

Fig. 28

SSON004X1010

Power dissipation heat reduction characteristics (Reference)

0

0.1

0.2

0.3

0.4

0.5

0.6

0

25

50

75

100

125

Ta [

℃]

0.56W

85

0.39W