+

-

2

7

8

5

4

1

6

3

Error

Amp

LP3879-X.X

BYPASS

N/C

GROUND

INPUT

SENSE

OUTPUT

N/C

SHUTDOWN

+

1.23V

LP3879

SNVS396B – MAY 2006 – REVISED APRIL 2013

www.ti.com

Block Diagram

APPLICATION INFORMATION

PACKAGE INFORMATION

The LP3879 is offered in the 8-lead SO PowerPad or WSON surface mount packages to allow for increased

power dissipation compared to the SO-8 and Mini SO-8.

EXTERNAL CAPACITORS

Like any low-dropout regulator, the LP3879 requires external capacitors for regulator stability. These capacitors

must be correctly selected for good performance.

INPUT CAPACITOR: A capacitor whose value is at least 4.7 µF (±20%) is required between the LP3879 input

and ground. A good quality X5R / X7R ceramic capacitor should be used.

Capacitor tolerance and temperature variation must be considered when selecting a capacitor (see Capacitor

Characteristics section) to assure the minimum requirement of input capacitance is met over all operating

conditions.

The input capacitor must be located not more than 0.5" from the input pin and returned to a clean analog ground.

Any good quality ceramic or tantalum capacitor may be used, assuming the minimum input capacitance

requirement is met.

OUTPUT CAPACITOR: The LP3879 requires a ceramic output capacitor whose size is at least 10 µF (±20%). A

good quality X5R / X7R ceramic capacitor should be used. Capacitance tolerance and temperature

characteristics must be considered when selecting an output capacitor.

The LP3879 is designed specifically to work with ceramic output capacitors, utilizing circuitry which allows the

regulator to be stable across the entire range of output current with an ultra low ESR output capacitor.

The output capacitor selected must meet the requirement for minimum amount of capacitance and also have an

ESR (equivalent series resistance) value which is within the stable range. A curve is provided which shows the

stable ESR range as a function of load current (see Figure 19).

8

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