BD8381EFV-E2 Rohm Semiconductor, BD8381EFV-E2 Datasheet - Page 16

• Manufacturer Part Number: BD8381EFV-E2
• Description: LED Drivers AUTOMOTIVE GRADE LED DRIVER
• Manufacturer: Rohm Semiconductor

Specifications of BD8381EFV-E2

• Operating Supply Voltage: 5 V to 30 V
• Maximum Supply Current: 7 mA
• Maximum Power Dissipation: 1.45 W
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: HTSSOP-28
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

●Power consumption calculation
＜Calculation example＞
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BD8381EFV-M
www.rohm.com
Pc(N) = ICC*VCC +
ICC ： Current of the maximum circuit
VCC ：Power-supply voltage
Ciss ： External FET capacity
Vsw ： SW gate voltage
Fsw ： SW frequency
F
When assuming
Pc(4) = 10mA × 30V + 500pF × 5V × 300kHz × 5V×2×2+
Pc = about 300mW.
Pd=2200mW (968mW) ： Density of the board copper foil 3%
Pd=3200mW (1408mW)： Density of the board copper foil 34%
Pd=3500mW (1540mW)： Density of the board copper foil 60%
it becomes
PWM
4
3
2
1
0
Note１：The value of Power consumption : on glass epoxy board measuring 70mm×70mm×1.6mm
Note２：The value changes depending on the density of the board copper foil.
： PWM frequency
(3) 3.12W
(2) 2.77W
(1) 1.88W
(1 layer board／Copper foil thickness 18μm)
25
However, this value is an actual measurement value and no guarantee value.
2
1
Ambient temperature Ta[℃]
50
*Ciss*VREG*Fsw*VREG×2×2+
(1) θja=66.5℃/W (Density of board copper foil3%)
(2) θja=45℃/W (Density of board copper foil34%)
(3) θja=40℃/W (Density of board copper foil60%)
Fig.21
75
95
100
125
150
16/20
1
2
×Ciss×VREG×F
2
1
×1500pF×5×200×5×2,
The value in () is a Power consumption of the Ta=125℃.
PWM
×VREG×2
2010.10 - Rev.0.11
Technical Note