LT3045

1

3045fa

For more information www.linear.com/LT3045

Typical applicaTion

FeaTures

DescripTion

20V, 500mA, Ultralow Noise,

Ultrahigh PSRR Linear Regulator

The LT®3045 is a high performance low dropout linear

regulator featuring LTC’s ultralow noise and ultrahigh

PSRR architecture for powering noise sensitive applica-

tions. Designed as a precision current reference followed

by a high performance voltage buffer, the LT3045 can be

easily paralleled to further reduce noise, increase output

current and spread heat on the PCB.

The device supplies 500mA at a typical 260mV dropout

voltage. Operating quiescent current is nominally 2.2mA

and drops to <<1µA in shutdown. The LT3045’s wide

output voltage range (0V to 15V) while maintaining unity-

gain operation provides virtually constant output noise,

PSRR, bandwidth and load regulation, independent of the

programmed output voltage. Additionally, the regulator

features programmable current limit, fast start-up capa-

bility and programmable power good to indicate output

voltage regulation.

TheLT3045isstablewithaminimum 10µFceramicoutput

capacitor. Built-in protection includes reverse-battery

protection, reverse-current protection, internal current

limit with foldback and thermal limit with hysteresis. The

LT3045 is available in thermally enhanced 12-Lead MSOP

and 10-Lead 3mm

× 3mm DFN packages.

Power Supply Ripple Rejection

applicaTions

n

n

Ultralow Spot Noise: 2nV/√Hz at 10kHz

n

Ultrahigh PSRR: 76dB at 1MHz

n

Output Current: 500mA

n

Wide Input Voltage Range: 1.8V to 20V

n

Single Capacitor Improves Noise and PSRR

n

100µA SET Pin Current: ±1% Initial Accuracy

n

Single Resistor Programs Output Voltage

n

High Bandwidth: 1MHz

n

Programmable Current Limit

n

Low Dropout Voltage: 260mV

n

Output Voltage Range: 0V to 15V

n

Programmable Power Good

n

Fast Start-Up Capability

n

Precision Enable/UVLO

n

Parallelable for Lower Noise and Higher Current

n

Internal Current Limit with Foldback

n

Minimum Output Capacitor: 10µF Ceramic

n

Reverse-Battery and Reverse-Current Protection

n

12-Lead MSOP and 10-Lead 3mm × 3mm DFN Packages

n

RF Power Supplies: PLLs, VCOs, Mixers, LNAs, PAs

n

Very Low Noise Instrumentation

n

High Speed/High Precision Data Converters

n

Medical Applications: Imaging, Diagnostics

n

Precision Power Supplies

n

Post-Regulator for Switching Supplies

L

, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog

Devices, Inc. Patents pending. All other trademarks are the property of their respective owners.

FREQUENCY (Hz)

10

100

1k

10k

100k

1M

10M

20

30

40

50

60

70

80

90

100

110

120

3045 TA01b

100µA

IN

EN/UV

PG

GND

OUT

LT3045

ILIM

PGFB

402k

10µF

4.7µF*

*OPTIONAL, SEE

APPLICATIONS

INFORMATION

5V ±5%

200k

4.7µF

3V

500mA

49.9k

3045 TA01a

249

30.1k

SET

OUTS