bd9763fvm ROHM Co. Ltd., bd9763fvm Datasheet - Page 11

• Manufacturer Part Number: bd9763fvm
• Description: Single-output Step-up, High-efficiency Switching Regulators Controller Type
• Manufacturer: ROHM Co. Ltd.

●Power Dissipation Reduction
(11) IC pin input
This monolithic IC contains P + isolation and PCB layers between adjacent elements in order to keep them isolated.
P/N junctions are formed at the intersection of these P layers with the N layers of other elements to create a variety
Of parasitic elements.
For example, when a resistor and transistor are connected to pins as shown in Fig.13,
The formation of parasitic elements as a result of the relationships of the potentials of different pins is an inevitable
result of the IC’s architecture. The operation of parasitic elements can cause interference with circuit operation as
well as IC malfunction and damage. For these reasons, it is necessary to use caution so that the IC is not used in a
way that will trigger the operation of parasitic elements, such as by the application of voltage lower than the GND
(PCB) voltage to input and output pins.
(Pin A)
Ｎ
Ｐ
IC mounted on a ROHM standard board (70mm x 70mm x 1.6mm, glass epoxy)
＋
pd(W)
○ the P/N junction functions as a parasitic diode when GND > (Pin A) for the resistor or GND > (Pin B) for
○ Similarly, when GND > (Pin B) for the transistor (NPN), the parasitic diode described above combines
the transistor (NPN).
With the N layer of other adjacent elements to operate as a parasitic NPN transistor.
Parasitic diode
0.8
0.6
0.4
0.2
0
Ｎ
PCB
Ｐ
GND
0
Ｐ
＋
25
AMBIENT TEMPERATURE ： Ta(℃）
Ｎ
50
(Pin B)
Parasitic transistors
Ｎ
Ｐ
＋
75
Ｃ
0.587W
11/12
Ｂ
Ｎ
PCB
100
Ｎ
Ｐ
GND
Ｅ
Ｐ
125
＋
Ｎ
GND
150
Other adjacent element
175
(Pin A)
(Pin B)
GND
Ｂ
Parasitic diode
Ｃ
Ｅ
GND
Parasitic elements