put capacitors with an ESR of 0.1

Ω or less to ensure sta-

bility and optimum transient response. Surface-mount

ceramic capacitors have very low ESR and are com-

minimize the impact of PC board trace inductance.

Noise, PSRR, and Transient Response

The MAX8887/MAX8888 are designed to operate with

low dropout voltages and low quiescent currents in bat-

tery-powered systems while still maintaining excellent

noise, transient response, and AC rejection. See the

Typical Operating Characteristics for a plot of power-

supply rejection ratio (PSRR) versus frequency. When

operating from noisy sources, improved supply-noise

rejection and transient response can be achieved by

increasing the values of the input and output bypass

capacitors and through passive filtering techniques.

Input-Output (Dropout) Voltage

A regulator’s minimum input-to-output voltage differen-

tial (dropout voltage) determines the lowest usable sup-

ply voltage at which the output is regulated. In

battery-powered systems, this determines the useful

end-of-life battery voltage. The MAX8887/MAX8888 use

a P-channel MOSFET pass transistor. Its dropout volt-

age is a function of drain-to-source on-resistance

Typical Operating Characteristics).

Chip Information

TRANSISTOR COUNT: 620

PROCESS: BiCMOS

Low-Dropout, 300mA Linear Regulators in SOT23

_______________________________________________________________________________________

7

SHUTDOWN

LOGIC

ERROR

AMP

1.25V

REF

95%

REF

P

OUT

POK

GND

IN

SHDN

MAX8888

THERMAL

SENSOR

MOS DRIVER

POK

Figure 1. Functional Diagram

0

100

200

300

400

0

1.0

2.0

3.0

0.5

1.5

2.5

3.5

4.0

MAXIMUM OUTPUT CURRENT

vs. INPUT VOLTAGE

(POWER DISSIPATION LIMIT)

MAXIMUM RECOMMENDED OUTPUT CURRENT

°C

°C

Figure 2. Power Operating Regions: Maximum Output Current

vs. Input Voltage