MC78FC00 Series

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4

APPLICATIONS INFORMATION

Introduction

The MC78FC00 micropower voltage regulators are

specifically designed with internal current limiting and low

quiescent current making them ideal for battery powered

applications. An input bypass capacitor is recommended if

the regulator is located an appreciable distance (

≥ 4 inches)

from the input voltage source. These regulators require

0.1

mF capacitance between the output terminal and ground

for stability. Most types of aluminum, tantalum or multilayer

ceramic will perform adequately. Solid tantalums or other

appropriate capacitors are recommended for operation

below 25

°C. The bypass capacitors should be mounted with

the shortest possible leads or track lengths directly across the

regulator input and output terminals.

With economical electrolytic capacitors, cold temperature

operation can pose a serious stability problem. As the

electrolyte freezes, around −30

°C, the capacitance will

decrease and the equivalent series resistance (ESR) will

increase drastically, causing the circuit to oscillate. Quality

electrolytic capacitors with extended temperature ranges of

−40

° to +85°C are readily available. Solid tantalum

capacitors may be the better choice if small size is a

requirement. However, a maximum ESR limit of 3.0

W must

be observed over temperature to maintain stability.

Figure 6 is a typical circuit application. Figure 7 is a

current boost circuit which can deliver more than 600 mA.

The circuit has no current limiting and the external transistor

must be rated for the expected power dissipation.

Figure 6. Typical Application

23

GND

GND

1

0.1

mF

0.1

mF

MC78FC00

Figure 7. Current Boost Circuit

23

GND

GND

1

0.1

mF

10

mF

MC78FC00

MJD32C

0.1

mF

100

.033

mF

ORDERING INFORMATION

Device

Device

Marking

Output

Voltage

Operating

Temperature Range

Package

MC78FC30HT1G

0K

3.0

SOT−89

(Pb−Free)

1000 / Tape & Reel

MC78FC33HT1G

3K

3.3

MC78FC40HT1G

0L

4.0

MC78FC50HT1G

0M

5.0

†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging

Specifications Brochure, BRD8011/D.

NOTE: Other voltages from 2.0 to 6.0 V, in 0.1 V increments, are available upon request. Consult factory for information.