bh25rb1wgut ROHM Co. Ltd., bh25rb1wgut Datasheet - Page 7

• Manufacturer Part Number: bh25rb1wgut
• Description: Ultra Small Package Cmos Ldo Regulators
• Manufacturer: ROHM Co. Ltd.

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BH□□RB1WGUT Series
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9.
10. Back Current
11. Testing on application boards
12. Regarding Input Pin of the IC (Fig.31)
Parasitic element
The potential of GND pin must be minimum potential in all operating conditions.
In applications where the IC may be exposed to back current flow, it is recommended to create a path to dissipate this
current by inserting a bypass diode between the VIN and VOUT pins.
When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to
stress. Always discharge capacitors after each process or step. Always turn the IC's power supply off before connecting
it to or removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as an
antistatic measure. Use similar precaution when transporting or storing 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 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.
Pin A
GND voltage
N
P
+
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.
N
GND
P
P substrate
P
+
N
Resistor
Fig. 30 Example Bypass Diode Connection
Fig. 31
Pin A
Example of IC structure
Parasitic
element
VIN
STBY
GND
Parasitic element
7/8
Pin B
N
Back current
P
OUT
+
C
B
N
E
GND
P
P substrate
Transistor (NPN)
P
+
N
GND
Other adjacent elements
Pin B
B
Technical Note
2009.09 - Rev.B
C
E
GND
Parasitic
element