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REV. D

Operation Notes

1. Absolute maximum range

This product are produced with strict quality control, but might be destroyed in using beyond absolute maximum ratings. Open IC

destroyed a failure mode cannot be defined (like Short mode, or Open mode).

Therefore physical security countermeasure, like fuse, is to be given when a specified mode to be beyond absolute maximum ratings

is considered.

2. Ground potential

GND terminal should be a lowest voltage potential every state.

Please make sure all pins which is over ground even if include transient feature.

3. Setting of heat

Use a setting of heat that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions..

4 . Short Circuit between Terminal and Soldering

Don’t short-circuit between Output pin and the power supply pin, Output pin and GND pin, or the power supply pin and GND pin.When soldering

the IC on circuit board, please be unusually cautious about the orientation and the

position of the IC. When the orientation is mistaken the IC may be destroyed.

5 . Electromagnetic Field

Mal-function may happen when the device is used in the strong electromagnetic field.

6. Ground wiring patterns

When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns, placing a

single ground point at the application's reference point so that the pattern wiring resistance and voltage variations caused

by large currents do not cause variations in the small signal ground voltage. Be careful not to change the GND wiring patterns

of any external components.

7. This IC is a monolithic IC which has P+ isolation in the P substrate and between the various pins.

A P-N junction is formed from this P layer and the N layer of each pin.

For example, when a resistor and a transistor is connected to a pin.

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.

8. Over current protection circuit

The over-current protection circuits are built in at output, according to their respective current outputs and prevent the IC

from being damaged when the load is short-circuited or over-current. But, these protection circuits are effective for preventing

destruction by unexpected accident. When it’s in continuous protection circuit moving period don’t use please. And for ability,

because this chip has minus characteristic, be careful for heat plan.

9. Built-in thermal circuit

A temperature control circuit is built in the IC to prevent the damage due to overheat.

Therefore, all the outputs are turned off when the thermal circuit works and are turned on when the temperature goes down to

the specified level.

10.Testing on application boards

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. Ground the IC

during assembly steps as an antistatic measure, and use similar caution when transporting or storing the

IC. Always turn the IC's power supply off before connecting it to or removing it from a jig or fixture

during the inspection process.

11.Discontiguous mode

The DC/DC converters of this IC are designed for being used in contiguous current mode, normally. The special consideration on adjusting

the inductance or the resistive output load to avoid the discontiguous current mode should be properly done.

Ｎ

parasitic diode

resister

（PinＡ）

（PinＢ）

parasitic diode or transistor

ＧＮＤ

Ｐsubstrate

Ｎ

Ｐ

Ｎ

Ｎ

Ｂ

Ｎ

Ｅ

Ｃ

ＧＮＤ

ＧＮＤ

（PinＡ）

Parasitic diode

ＧＮＤ

（PinＢ）

Ｂ

Ｃ

Ｅ

near-by other element

parasitic diode or transistor

SIMPLIFIED STRUCTURE OF

BI-POLAR IC