HIGH RIPPLE-REJECTION LOW DROPOUT CMOS VOLTAGE REGULATOR

S-1165 Series

Seiko Instruments Inc.

14



Precautions

• Wiring patterns for the VIN pin, the VOUT pin and GND should be designed so that the impedance is

these pins should be as short as possible.

• Note that generally the output voltage may increase when a series regulator is used at low load current

(1.0 mA or less).

• The S-1165 Series performs phase compensation by using an internal phase compensator and the ESR

of an output capacitor. Therefore, always place a capacitor of 2.2

μF or more between VOUT and VSS

pins. A tantalum type capacitor is recommended. Moreover, to secure stable operation of the S-1165

Series, it is necessary to employ a capacitor with an ESR within an optimum range (0.5

Ω to 5 Ω).

Using a capacitor whose ESR is outside the optimum range (approximately 0.5

Ω to 5 Ω), whether larger

or smaller, may cause an unstable output, resulting in oscillation. Perform sufficient evaluation under

the actual usage conditions for selection, including evaluation of temperature characteristics.

• The voltage regulator may oscillate when the impedance of the power supply is high and the input

capacitance is small or an input capacitor is not connected.

• Overshoot may occur in the output voltage momentarily if the voltage is rapidly raised at power-on or

when the power supply fluctuates. Sufficiently evaluate the output voltage at power-on with the actual

device.

• The application conditions for the input voltage, the output voltage, and the load current should not

exceed the package power dissipation.

• Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the built-in

electrostatic protection circuit.

• In determining the output current, attention should be paid to the output current value specified in Table

4 in “ Electrical Characteristics” and footnote *5 of the table.

• SII claims no responsibility for any disputes arising out of or in connection with any infringement by

products including this IC of patents owned by a third party.