Datasheet LT3042 (Analog Devices)

LT3042 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator
FEATURES DESCRIPTION
n
Ultralow RMS Noise: 0.8µVRMS (10Hz to 100kHz)
The LT®3042 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: 79dB at 1MHz
architecture for powering noise sensitive RF applications. n
Output Current: 200mA
Designed as a precision current reference followed by a n
Wide Input Voltage Range: 1.8V to 20V
high performance voltage buffer, the LT3042 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. n Single Resistor Programs Output Voltage The device supplies 200mA at a typical 350mV dropout n High Bandwidth: 1MHz voltage. Operating quiescent current is nominally 2mA n Programmable Current Limit and drops to <<1µA in shutdown. The LT3042’s wide n Low Dropout Voltage: 350mV 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: 4.7µF Ceramic n Reverse Battery and Reverse Current Protection The LT3042 is stable with a minimum 4.7µF ceramic n 10-Lead MSOP and 3mm × 3mm DFN Packages output capacitor. Built-in protection includes reverse bat- tery protection, reverse current protection, internal current limit with foldback and thermal limit with hysteresis. The
APPLICATIONS
LT3042 is available in thermally enhanced 10-Lead MSOP n RF Power Supplies: PLLs, VCOs, Mixers, LNAs and 3mm × 3mm DFN packages. n Very Low Noise Instrumentation All registered trademarks and trademarks are the property of their respective owners. Patents n High Speed/High Precision Data Converters Pending. n Medical Applications: Imaging, Diagnostics n Precision Power Supplies n Post-Regulator for Switching Supplies
TYPICAL APPLICATION Power Supply Ripple Rejection
120 LT3042 110 V IN IN 5V ±5% 100 4.7µF 100µA 90 – EN/UV 80 + 200k VOUT OUT 3.3V 70 PG IOUT(MAX) OUTS PSRR (dB) 60 200mA 50 V SET GND ILIM PGFB 4.7µF IN = 5V 453k R 40 SET = 33.2kΩ 1% CSET = 4.7µF 30 COUT = 4.7µF 499Ω I 49.9k L = 200mA 4.7µF 33.2k 20 1% 1% 10 100 1k 10k 100k 1M 10M 3042 TA01a FREQUENCY (Hz) 3042 TA01b 3042fb For more information www.linear.com/LT3042 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