BD9207FPS
Technical Note
10. This IC is a monolithic IC, and there are P + isolation and P substrate for element separation between each
element. P-N joint is formed with this P layer and N each element’s layer, and various parasitic elements are
composed.
For instance, as shown in the figure below, when resistance and transistor are connected with terminal:
○ P-N joint operates as a parasitic diode when GND > (terminal A) in resistance, GND >(terminal B) in transistor
(NPN).
○ Moreover, when GND > (terminal B) in transistor (NPN),the parasitic NPN transistor operates with N layer of other
elements adjoining with above-mentioned parasitic diode.
According to potential relation, parasitic element in IC structure can be consequent. The operating of parasitic
element maybe interfere the circuit operation, and become the cause of malfunction and destruction. Therefore,
please pay enough attention not to use it by impressing lower voltage than GND (P substrate) on I/O terminal etc
to operate parasitic element.
(TerminalA)
Resistance
(TerminalB)
Transistor(NPN)
B
C
E
P+
N
Psubstrate
P
N
P+
N
Parasitic element
GND
P+
N
N
P
N
GND
P+
N
Parasitic element
Psubstrate
GND
(TerminalA)
(TerminalB)
Parasitic element
C
B
E
GND
other adjoining elements
Simple structure example of bipolar IC
GND
Parasitic element
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10/11
2009.07 - Rev.A