5V/3.3V or Adjustable, Low-Dropout,

_______________________________________________________________________________________

9

Foldback Current Limiting

The MAX882/MAX883/MAX884 also include a foldback

current limiter. It monitors and controls the pass transis-

tor’s gate voltage, estimating the output current and

limiting it to 430mA for output voltages above 0.8V and

0.8V, implying a short-circuit condition, the output cur-

rent is limited to 170mA. The output can be shorted to

ground for 1min without damaging the device if the

limiting is allowed, to provide maximum load drive.

Thermal Overload Protection

Thermal overload protection limits total power dissipa-

tion in the MAX882/MAX883/MAX884. When the junc-

sensor sends a signal to the shutdown logic, turning off

the pass transistor and allowing the IC to cool. The

thermal sensor turns the pass transistor on again after

the IC’s junction temperature cools by 10°C, resulting in

a pulsed output during thermal overload conditions.

Thermal overload protection is designed to protect the

MAX882/MAX883/MAX884 if fault conditions occur. It is

not intended to be used as an operating mode.

Prolonged operation in thermal-shutdown mode may

reduce the IC’s reliability. For continual operation, do

not exceed the absolute maximum junction temperature

Power Dissipation and Operating Region

Maximum power dissipation of the MAX882/MAX883/

MAX884 depends on the thermal resistance of the case

and PC board, the temperature difference between the

die junction and ambient air, and the rate of

air flow. The power dissipation across the device is

is as follows:

the MAX882/MAX883/MAX884 die junction and the sur-

rounding air,

the package chosen, and

through the PC board, copper traces, and other materi-

als to the surrounding air.

The 8-pin small-outline package for the MAX882/

MAX883/MAX884 features a special lead frame with a

lower thermal resistance and higher allowable power

dissipation. This package’s thermal resistance package

is

8-pin plastic DIP package and

pin ceramic DIP package.

P

(T

T )

()

JA

JB

BA

=

−

+

θθ

Figure 2. Adjustable Output Using External Feedback

Resistors

Figure 3. Setting an Undervoltage Lockout Threshold Using

STBY

MAX882

MAX883

MAX884

O.1

μF

2.2

μF

OUTPUT

VOLTAGE

INPUT

VOLTAGE

LBI

OFF

(STBY)

( ) ARE FOR MAX882.

IN

R1

R2

R1 + R2

R2

LOAD

OUT

GND

SET

MAX882

O.1

μF

2.2

μF

OUTPUT

VOLTAGE

INPUT

VOLTAGE

LBI

SET

STBY

IN

R1

R2

R1+ R2

R2

OUT

GND