bd67929efv ROHM Co. Ltd., bd67929efv Datasheet - Page 11

• Manufacturer Part Number: bd67929efv
• Description: Three-phase Brushless Motor Driver For Polygonal Mirrors [for Lbp, Ppc]
• Manufacturer: ROHM Co. Ltd.

●Power Dissipation
BD67929EFV
© 2010 ROHM Co., Ltd. All rights reserved.
www.rohm.com
○HTSSOP-B28 Package
HTSSOP-B28 has exposed metal on the back, and it is possible to dissipate heat from a through hole in the back. Also,
the back of board as well as the surfaces has large areas of copper foil heat dissipation patterns, greatly increasing
power dissipation. The back metal is shorted with the back side of the IC chip, being a GND potential, therefore there is a
possibility for malfunction if it is shorted with any potential other than GND, which should be avoided. Also, it is
recommended that the back metal is soldered onto the GND to short. Please note that it has been assumed that this
product will be used in the condition of this back metal performed heat dissipation treatment for increasing heat
dissipation efficiency.
5.0
4.0
3.0
2.0
1.0
0
4.70W
3.30W
1.85W
1.45W
4
3
2
1
Ambient Temperature:Ta[℃]
HTSSOP-B28 Derating Curve
100
11/14
125
Board③：2-layer board(Copper foil on the back 70*70mm
Board④：4-layer board(Copper foil on the back 70*70mm
Measurement machine：TH156(Kuwano Electric)
Measurement condition：ROHM board
Board size：70*70*1.6mm
(With through holes on the board)
Board①：1-layer board(Copper foil on the back 0mm
Board②：2-layer board(Copper foil on the back 15*15mm
Board①：θja=86.2℃/W
Board②：θja=67.6℃/W
Board③：θja=37.9℃/W
Board④：θja=26.6℃/W
3
Technical Note
2010.12 - Rev.A
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