AN30185A

10

Ver. BEB

OPERATION

BUF(0.9V)

DC-DC2(1.8V)

External Pch-MOSFE

Gate control circuit

OFF

OFF

OFF

OFF

Low

OFF

OFF

ON

ON

Low

OFF

ON

OFF

ON

High

High

EN2

OFF

ON

DC-DC1(1.0V)

OFF

ON

Low

High

EN

EN pin is the main control pin. When EN pin becomes High, DC-DC1 and external Pch-MOSFET gate control circuit

turn on,and DC-DC2 and BUF become controllable by EN2 pin.

EN2 pin is the control pin for DC-DC2 and BUF. When EN2 pin becomes High, DC-DC2 and BUF turn on.

Even if EN2 is High under the condition that EN is Low, DC-DC2 and BUF do not turn on.

1. Pin Setting For Start / Stop Control