HIGH RIPPLE-REJECTION LOW DROPOUT CMOS VOLTAGE REGULATOR

S-T111 Series

Seiko Instruments Inc.

12

3. ON/OFF pin

This pin starts and stops the regulator.

When the ON/OFF pin is set to OFF level, the entire internal circuit stops operating, and the built-in

P-channel MOS FET output transistor between the VIN pin and the VOUT pin is turned off, reducing

resistance of several M

Ω between the VOUT pin and the VSS pin.

The structure of the ON/OFF pin is as shown in Figure 12. Since the ON/OFF pin is neither pulled down

nor pulled up internally, do not use it in the floating status. In addition, note that the current consumption

pin, connect it to the VSS pin in the product A type, and connect it to the VIN pin in B type.

Table 5

Product Type

ON/OFF Pin

Internal Circuit

VOUT Pin Voltage

Current Consumption

A

“L”: ON

Operate

Set value

A

“H”: OFF

Stop

B

“L”: OFF

Stop

B

“H”: ON

Operate

Set value

VSS

ON/OFF

VIN

Figure 12