BH1726NUC Datasheet, PDF (13/20 Pages) Rohm – Digital 16bit Serial Output Type Ambient Light Sensor IC

BH1726NUC
Operational Notes – continued
12. Regarding the Input Pin of the IC
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 the P layers with the N layers of other elements, creating a
parasitic diode or transistor. For example (refer to figure below):
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.
Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to
operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be
avoided.
Resistor
Transistor (NPN)
Pin A
Pin A
Pin B
C
B
E
Pin B
P⁺
N
N
Parasitic
Elements
P
P⁺
N
N
P Substrate
GND
Parasitic
Elements
N ^P+
N _{P N P}⁺ _N
P Substrate
Parasitic
GND GND
Elements
Figure 2. Example of monolithic IC structure
B
N Region
close-by
C
E
Parasitic
Elements
GND
13. Ceramic Capacitor
When using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with
temperature and the decrease in nominal capacitance due to DC bias and others.
14. Area of Safe Operation (ASO)
Operate the IC such that the output voltage, output current, and power dissipation are all within the Area of Safe
Operation (ASO).
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TSZ22111・15・001
13/16
TSZ02201-0M3M0F616020-1-2
28.Apr.2016 Rev.001