BA51W12SAT

Regulator ICs

(9) Recommended to put diode for protection in case of output pin connected with large load of impedance or reserve

current occurred at initial and output off.

Output

(Example)

(10) When used within a strong magnetic field, be aware that there is a slight possibility of malfunction.

(11) We are confident in recommending the above application circuit example, but we ask that you carefully check the

characteristics of this circuit before using it. If using circuit after modifying other external circuit constants, be careful to

ensure adequate margins for variation between external devices and this IC, including not only static characteristics

but also transient characteristics.

This IC is a bipolar IC which (as shown in Figure 9) has P+ isolation in the P substrate and between the various pins.

A P-N junction is formed form this P layer and the N layer of each pin. For example the relation between each

potentials is as follows,

(When GND > PinB and GND > PinA, the P-N junction operates as a parasitic diode.)

(When PinB > GND > PinA, the P-N junction operates as a parasitic transistor.)

Parasitic diodes can occur inevitably in the structure of the IC. The operation of parasitic diodes can result in mutual

interference among circuits as well as operation faults and physical damage. Accordingly, you must not use methods

by which parasitic diodes operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an

input pin.

(Pin A)

(Pin A)

Resistance

P substrate

N

GND

GND

N

P

N

P

+

P

+

Parasitic diode

Parasitic diode

(Pin B)

Transistor (NPN)

P substrate

N

C

B

E

GND

N

N

P

N

P

+

P

+

Parasitic diode or

transistor

Parasitic diode

or transistor

GND

(Pin B)

GND

C

E

B

Fig.9 Simplified structure of bipolar IC