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FEATURES

DESCRIPTION

APPLICATIONS

OUT

NC − No internal connection

1

2

3

4

5

DCQ PACKAGE

NR

OUT

GND

IN

EN

2

1

3

4

7

8

6

5

NC

FB

NR

IN

NC

EN

GND

SOT223-6

(TOP VIEW)

DGN PACKAGE

MSOP PowerPAD

(TOP VIEW)

40

20

10

10

100

1 k

10 k

60

70

Frequency (Hz)

TPS79433

RIPPLE REJECTION

vs

FREQUENCY

90

100 k

1 M

10 M

0

30

50

80

0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

TPS79428

OUTPUT SPECTRAL NOISE DENSITY

vs

FREQUENCY

Frequency (Hz)

100

1000

10000

100000

6

GND

TPS79401, TPS79418

TPS79425, TPS79428

TPS79430, TPS79433

SLVS349D – NOVEMBER 2001 – REVISED OCTOBER 2004

ULTRALOW-NOISE, HIGH PSRR, FAST RF 250-mA LOW-DROPOUT LINEAR

REGULATORS

•

250-mA Low-Dropout Regulator With Enable

The TPS794xx family of low-dropout (LDO) linear

voltage regulators features high power-supply rejec-

•

Available in 1.8 V, 2.5 V, 2.8 V, 3 V, 3.3 V, and

tion ratio (PSRR), ultralow-noise, fast start-up, and

Adjustable (1.2 V to 5.5 V)

excellent line and load transient responses in small

•

High PSRR (60 dB at 10 kHz)

outline, MSOP-8 PowerPAD™ and SOT223-6 pack-

•

Ultralow Noise (32 µVrms, TPS79428)

ages. Each device in the family is stable with a small

2.2-µF ceramic capacitor on the output. The family

•

Fast Start-Up Time (50 µs)

uses an advanced, proprietary BiCMOS fabrication

•

Stable With a 2.2-µF Ceramic Capacitor

process to yield extremely low dropout voltages (e.g.,

•

Excellent Load/Line Transient Response

155 mV at 250 mA). Each device achieves fast

start-up times (approximately 50 µs with a 0.001-µF

•

Very Low Dropout Voltage (155 mV at Full

bypass capacitor) while consuming low quiescent

Load)

current (170 µA typical). Moreover, when the device

•

Available in MSOP-8 and SOT223-6 Packages

is placed in standby mode, the supply current is

reduced to less than 1 µA. The TPS79428 exhibits

•

RF: VCOs, Receivers, ADCs

2.8 V output with a 0.1-µF bypass capacitor. Appli-

cations

with

analog

components

that

are

•

Audio

noise-sensitive, such as portable RF electronics,

•

Bluetooth™, Wireless LAN

benefit from the high PSRR and low noise features as

•

Cellular and Cordless Telephones

well as the fast response time.

•

Handheld Organizers, PDAs

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

Bluetooth is a trademark of Bluetooth SIG, Inc.

PowerPAD is a trademark of Texas Instruments.

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2001–2004, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.