Low-Noise, Low-Dropout,

150mA Linear Regulators in SOT23

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ESR variation with temperature. With dielectrics such as

Z5U and Y5V, it may be necessary to use 2.2µF or

more to ensure stability at temperatures below -10°C.

With X7R or X5R dielectrics, 1µF should be sufficient at

all operating temperatures. Also, for high-ESR tantalum

capacitors, 2.2µF or more may be needed to maintain

ESR in the stable region. A graph of the Region of

Typical Operating Characteristics.

Use a 0.01µF bypass capacitor at BP for low output volt-

age noise. Increasing the capacitance will slightly

decrease the output noise, but increase the start-up time.

Values above 0.1µF provide no performance advantage

and are not recommended (see Shutdown Exit Delay

graph in the

Typical Operating Characteristics).

PSRR and Operation from

Sources Other than Batteries

The MAX8867/MAX8868 are designed to deliver low

dropout voltages and low quiescent currents in battery-

powered systems. Power-supply rejection is 63dB at

low frequencies and rolls off above 10kHz. See the

Power-Supply Rejection Ratio Frequency graph in the

Typical Operating Characteristics.

When operating from sources other than batteries,

improved supply-noise rejection and transient response

can be achieved by increasing the values of the input

and output bypass capacitors, and through passive filter-

ing techniques. The

Typical Operating Characteristics

show the MAX8867/MAX8868’s line- and load-transient

responses.

Load-Transient Considerations

The MAX8867/MAX8868 load-transient response

graphs (see

Typical Operating Characteristics) show

two components of the output response: a DC shift

from the output impedance due to the load current

change, and the transient response. A typical transient

for a step change in the load current from 0mA to 50mA

is 12mV. Increasing the output capacitor’s value and

decreasing the ESR attenuates the overshoot.

Input-Output (Dropout) Voltage

A regulator’s minimum input-output voltage differential

(or dropout voltage) determines the lowest usable sup-

ply voltage. In battery-powered systems, this will deter-

mine the useful end-of-life battery voltage. Because the

MAX8867/MAX8868 use a P-channel MOSFET pass

transistor, their dropout voltage is a function of drain-to-

current (see

Typical Operating Characteristics).

___________________Chip Information

________________________________________________________Package Information

TRANSISTOR COUNT: 247

SUBSTRATE CONNECTED TO GND