bd6761fs ROHM Co. Ltd., bd6761fs Datasheet - Page 23

• Manufacturer Part Number: bd6761fs
• Description: Motor Driver Ic Series For Printers Three-phase Brushless Motor Pre-driver For Paper Feed Us
• Manufacturer: ROHM Co. Ltd.

12. Regarding input pin of the IC
13. Ground Wiring Pattern
Parasitic element
Pin A
N
This monolithic IC contains P+ isolation and P substrate 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, creating a parasitic diode or
transistor. For example, the relation between each potential is as follows:
Parasitic diodes can occur inevitable in the structure of the IC. The operation of parasitic diodes can result in mutual interference
among circuits, operational faults, or physical damage. Accordingly, methods by which parasitic diodes operate, such as
applying a voltage that is lower than the GND (P substrate) voltage to an input pin, should not be used.
When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns, placing a
single ground point at the ground potential of application so that the pattern wiring resistance and voltage variations caused by
large currents do not cause variations in the small signal ground voltage. Be careful not to change the GND wiring pattern of
any external components, either.
P
+
N
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
GND
P
P substrate
P
+
N
Resistor
Pin A
Fig.31 Example of IC structure
Parasitic
element
Parasitic element
23/24
Pin B
N
P
+
C
B
N
E
GND
P
P substrate
Transistor (NPN)
P
+
N
GND
Other adjacent elements
Pin B
B
C
E
GND
Parasitic
element