STEP-DOWN, 600 kHz PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER

S-8540/8541 Series

12

This pin deactivates or activates the step-down operation.

When the

OFF

/

ON

switching transistor to go off. All the internal circuits stop working, and substantial savings in current

consumption are thus achieved.

The

OFF

/

ON

pin is configured as shown in Figure 10. Since pull-up or pull-down is not performed

internally, please avoid operating the pin in a floating state. Also, try to refrain from applying a voltage of

0.3 to 1.8 V to the pin, lest the current consumption increase. When this

OFF

/

ON

pin is not used,

leave it coupled to the VIN pin.

Table 7

OFF

/

ON

Pin

CR Oscillation Circuit

Output Voltage

“H”

Activated

Set value

“L”

Deactivated

OPEN

ON/OFF

VIN

VSS

Figure 10