October 2004

1

M9999-100604

MIC5319

Micrel

MIC5319

General Description

The MIC5319 is a high-performance, 500mA LDO regulator,

offering extremely high PSRR and very low noise while

consuming low ground current.

Ideal for battery-operated applications, the MIC5319 fea-

tures 1% accuracy, extremely low-dropout voltage (200mV

@ 500mA), and low ground current at light load (typically

90µA). Equipped with a logic-compatible enable pin, the

MIC5319 can be put into a zero-off-mode current state,

drawing no current when disabled.

The MIC5319 is a µCap design operating with very small

ceramic output capacitors for stability, thereby reducing

required board space and component cost.

The MIC5319 is available in fixed-output voltages and adjust-

able output voltages in the super-compact 2mm x 2mm

MLF™ leadless package and thin SOT-23-5 package.

Additional voltage options are available. Contact Micrel

marketing.

All support documentation can be found on Micrel’s web

site at www.micrel.com.

Typical Application

Features

• Ultra-low dropout voltage 200mV @ 500mA

• Input voltage range: 2.5 to 5.5V

• Stable with ceramic output capacitor

• Low output noise — 40µVrms

• Low quiescent current of 90

• High PSRR, up to 70dB @1kHz

• Fast turn-on-time — 40µs typical

• High output accuracy:

• ±1.0% initial accuracy

• ±2.0% over temperature

• Thermal shutdown protection

• Current-limit protection

• Logic-controlled Enable

• Tiny 2mm x 2mm MLF™ package, 500mA continuous

• Thin SOT-23-5 package, 500mA peak

Applications

• Cellular phones

• PDAs

• Fiber optic modules

• Portable electronics

• Notebook PCs

• Audio Codec power supplies

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

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FREQUENCY (Hz)

PSRR

(Bypass Pin Cap = 0.1µF)

50mA

500mA

100µA

1k

10

100

10k

100k

1M

Vout = 2.8V

Vin = Vout + 1V

Cout = 2.2uF

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40

60

80

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120

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180

200

OUTPUT CURRENT (mA)

Dropout Voltage

Vout = 2.8V

Cout = 2.2uF

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100

200

300

400

500

MIC5319

VOUT

VIN

BYP

EN

GND

2.8V@500mA

2.2

µF

0.1

µF

1

µF