LT3045 20V, 500mA, Ultralow Noise, Ultrahigh PSRR Linear Regulator FEATURESDESCRIPTION n Ultralow RMS Noise: 0.8µVRMS (10Hz to 100kHz) The LT®3045 is a high performance low dropout linear n Ultralow Spot Noise: 2nV/√Hz at 10kHz regulator featuring LTC’s ultralow noise and ultrahigh n Ultrahigh PSRR: 76dB at 1MHz PSRR architecture for powering noise sensitive applica- n Output Current: 500mA tions. Designed as a precision current reference followed n Wide Input Voltage Range: 1.8V to 20V by a high performance voltage buffer, the LT3045 can be n Single Capacitor Improves Noise and PSRR easily paralleled to further reduce noise, increase output n 100µA SET Pin Current: ±1% Initial Accuracy current and spread heat on the PCB. n Single Resistor Programs Output Voltage The device supplies 500mA at a typical 260mV dropout n High Bandwidth: 1MHz voltage. Operating quiescent current is nominally 2.2mA n Programmable Current Limit and drops to <<1µA in shutdown. The LT3045’s wide n Low Dropout Voltage: 260mV output voltage range (0V to 15V) while maintaining unity- n Output Voltage Range: 0V to 15V gain operation provides virtually constant output noise, n Programmable Power Good PSRR, bandwidth and load regulation, independent of the n Fast Start-Up Capability programmed output voltage. Additionally, the regulator n Precision Enable/UVLO features programmable current limit, fast start-up capa- n Parallelable for Lower Noise and Higher Current bility and programmable power good to indicate output n Internal Current Limit with Foldback voltage regulation. n Minimum Output Capacitor: 10µF Ceramic n Reverse-Battery and Reverse-Current Protection The LT3045 is stable with a minimum 10µF ceramic output n 12-Lead MSOP and 10-Lead 3mm × 3mm DFN Packages capacitor. Built-in protection includes reverse-battery protection, reverse-current protection, internal current limit with foldback and thermal limit with hysteresis. The APPLICATIONS LT3045 is available in thermally enhanced 12-Lead MSOP n RF Power Supplies: PLLs, VCOs, Mixers, LNAs, PAs and 10-Lead 3mm × 3mm DFN packages. n Very Low Noise Instrumentation All registered trademarks and trademarks are the property of their respective owners. n High Speed/High Precision Data Converters n Medical Applications: Imaging, Diagnostics n Precision Power Supplies n Post-Regulator for Switching Supplies TYPICAL APPLICATIONPower Supply Ripple Rejection 120 V IN LT3045 110 IN 5V ±5% 100 4.7µF* 100µA 90 – EN/UV 80 + 200k VOUT OUT 3V 70 PG IOUT(MAX) OUTS 500mA PSRR (dB) 60 SET GND ILIM PGFB 10µF 50 VIN = 5V R 402k SET = 30.1k 40 CSET = 4.7µF C 30 OUT = 10µF 249Ω IL = 500mA 4.7µF 30.1k 49.9k *OPTIONAL, SEE 2010 100 1k 10k 100k 1M 10M APPLICATIONSINFORMATION 3045 TA01a FREQUENCY (Hz) 3045 TA01b Rev. B Document Feedback For more information www.analog.com 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
