GENERAL DESCRIPTION

The LT3046 is a high-performance, low-dropout linear

regulator featuring Analog Devices, Inc. ultra-low noise

and ultra-high PSRR architecture for powering noisesensitive

applications. Designed as a precision current

reference followed by a high-performance voltage

buffer, the LT3046 can be easily paralleled to further

reduce noise, increase output current, and spread heat

on the PCB.

The device supplies 200mA at a typical 300mV dropout

voltage. Operating quiescent current is nominally

3.7mA and drops to 26μA in shutdown. The LT3046’s

wide output-voltage range (0.2V to 19V) 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 capability,

and programmable power good to indicate output

voltage regulation.

Built-in protection includes reverse-battery protection,

reverse-current protection, internal current limit with

foldback and thermal limit with hysteresis. The LT3046

is available in a thermally enhanced, 12-lead, 3mm ×

3mm, DFN package.

FEATURES

? Ultra-Low RMS Noise: 0.8μVRMS (10Hz to 100kHz)

? Ultra-Low Noise: 2.2nV/√Hz at 10kHz

? Ultra-Low 1/f Noise: 2.5μVP-P (0.1Hz to 10Hz)

? Ultra-High PSRR: 82dB at 1MHz

? Output Current: 200mA

? Wide Input-Voltage Range: 2.2V to 20V

? Single Capacitor Improves Noise and PSRR

? SET Pin Current: 100μA, ±0.5 Initial Accuracy

? Single Resistor Programs Output Voltage

? Programmable Current Limit

? Low Dropout Voltage: 300mV

? Output-Voltage Range: 0.2V to 19V

? Programmable Power Good

? Fast Start-Up Capability

? Precision Enable/UVLO

? Parallelable for Lower Noise and Higher Current

? Internal Current Limit with Foldback

? Minimum Output Capacitor: 4.7μF Ceramic

? Compact, Low-Profile, 12-Lead, 3mm × 3mm, DFN Package

APPLICATIONS

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

? Very Low-Noise Instrumentation

? High-Speed/High-Precision Data Converters

? Post-Regulator for Switching Supplies