Datasheet LT3045-1 (Analog Devices)

LT3045-1 20V, 500mA, Ultralow Noise, Ultrahigh PSRR Linear Regulator with VIOC Control
FEATURES DESCRIPTION
n
Ultralow RMS Noise: 0.8µVRMS (10Hz to 100kHz)
The LT®3045-1 is a high performance low dropout linear n
Ultralow Spot Noise: 2nV/√Hz at 10kHz
regulator featuring LTC’s ultralow noise and ultrahigh PSRR n
Ultrahigh PSRR: 76dB at 1MHz
architecture for powering noise sensitive applications. De- n
Output Current: 500mA
signed as a precision current reference followed by a high n
Wide Input Voltage Range: 1.8V to 20V
performance voltage buffer, the LT3045-1 can be easily n
Single Capacitor Improves Noise and PSRR
paralleled to further reduce noise, increase output current n
100µA SET Pin Current: ±1% Initial Accuracy
and spread heat on the PCB. In addition to the LT3045 n
VIOC Pin Controls Upstream Regulator to Minimize
feature set, the LT3045-1 incorporates a VIOC tracking
Power Dissipation
function to control an upstream switching converter to n Single Resistor Programs Output Voltage maintain a constant voltage across the LT3045-1 and n Programmable Current Limit hence minimize power dissipation. n Low Dropout Voltage: 260mV The device supplies 500mA at a typical 260mV dropout n Output Voltage Range: 0V to 15V voltage. Operating quiescent current is nominally 2.3mA n Programmable Power Good and drops to <<1µA in shutdown. The LT3045-1’s wide n Fast Start-Up Capability output voltage range (0V to 15V) while maintaining unity- n Precision Enable/UVLO gain operation provides virtually constant output noise, n Parallelable for Lower Noise and Higher Current PSRR, bandwidth and load regulation, independent of the n Internal Current Limit with Foldback programmed output voltage. Additionally, the regulator n Minimum Output Capacitor: 10µF Ceramic features programmable current limit, fast start-up capa- n Reverse-Battery and Reverse-Current Protection bility and programmable power good to indicate output n 12-Lead MSOP and 3mm × 3mm DFN Packages voltage regulation. The LT3045-1 is stable with a minimum 10µF ceramic
APPLICATIONS
output capacitor. Built-in protection includes reverse- n RF Power Supplies: PLLs, VCOs, Mixers, LNAs, PAs battery protection, reverse-current protection, internal n Very Low Noise Instrumentation current limit with foldback and thermal limit with hysteresis. n High Speed/High Precision Data Converters The LT3045-1 is available in thermally enhanced 12-Lead n Medical Applications: Imaging, Diagnostics MSOP and 3mm × 3mm DFN packages. 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.
TYPICAL APPLICATION Noise Spectral Density
1000 0.22µF LDOIN = 4.3V 2.2µH V LT8608 IN LT3045-1 LDO IN OUT = 3.3V 12V IN BST I 100 LOAD = 500mA 47µF 100µA EN/UV SW EN/UV – ) TR/SS PG PGFB Hz 10 10nF + V/√ OUT V MODE OUT: VARIABLE 2.21k IOUT(MAX): 500mA RT FB OUTS 1 VIOC NOISE (µ 40.2k 7.68k VLDOIN – VLDOUT = 1V SET GND ILIM PG INTV 10µF CC GND 0.1 30451 TA01a LDO 1µF OUT LDOIN 249Ω Noise Floor 4.7µF 0.01 fSW = 1MHz 10 100 1k 10k 100k 1M 10M L: XFL4020-222MEC FREQUENCY (Hz) 30451 TA01b 30451fa For more information www.linear.com/LT3045-1 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Revision History Typical Application Related Parts