Technical Note

10/11

BD00C0AWFP,BD00C0AWCP-V5

www.rohm.com

2011.08 - Rev.B

© 2011 ROHM Co., Ltd. All rights reserved.

16. Applications or inspection processes where the potential of the Vcc pin or other pins may be reversed from their normal

state may cause damage to the IC's internal circuitry or elements. Use an output pin capacitance of 1000µF or lower in

case Vcc is shorted with the GND pin while the external capacitor is charged. Insert a diode in series with Vcc to prevent

reverse current flow, or insert bypass diodes between Vcc and each pin.

17. Positive voltage surges on VCC pin

A power zener diode should be inserted between VCC and GND for protection against voltage surges of more than 35V on

the VCC pin.

18. Negative voltage surges on VCC pin

A schottky barrier diode should be inserted between VCC and GND for protection against voltages lower than GND on the

VCC pin.

19. Output protection diode

Loads with large inductance components may cause reverse current flow during startup or shutdown. In such cases, a

protection diode should be inserted on the output to protect the IC.

20. Regarding input pins of the IC

This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated.

PN junctions are formed at the intersection of these P layers with the N layers of other elements, creating parasitic diodes

and/or transistors. For example (refer to the figure below):

○

When GND > Pin A and GND > Pin B, the PN junction operates as a parasitic diode

○

When GND > Pin B, the PN junction operates as a parasitic transistor

Parasitic diodes occur inevitably in the structure of the IC, and the operation of these parasitic diodes can result in mutual

interference among circuits, operational faults, or physical damage. Accordingly, 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.

Vcc

GND

Vcc

GND

Example of Simple Monolithic IC Architecture

Parasitic elements

(Pin A)

Parasitic elements

or transistors

(Pin B)

C

B

E

N

P

N

N

P+

P+

Parasitic elements

or transistors

P substrate

(Pin B)

C

B

E

Transistor (NPN)

(Pin A)

N

P

N

N

P+

P+

Resistor

Parasitic elements

P

GND

GND

GND

N