LT3042 - 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator


  • Ultralow RMS Noise: 0.8μVRMS (10Hz to 100kHz)
  • Ultralow Spot Noise: 2nV/√Hz at 10kHz
  • Ultrahigh PSRR: 79dB at 1MHz
  • Output Current: 200mA
  • Wide Input Voltage Range: 1.8V to 20V
  • Single Capacitor Improves Noise and PSRR
  • 100μA SET Pin Current: ±1% Initial Accuracy
  • Single Resistor Programs Output Voltage
  • High Bandwidth: 1MHz
  • Programmable Current Limit
  • Low Dropout Voltage: 350mV
  • Output Voltage Range: 0V to 15V
  • 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
  • Reverse Battery and Reverse Current Protection
  • 10-Lead MSOP and 3mm × 3mm DFN Packages

Typical Application

LT3042 Typical Application
LT3042 Typical Application


The LT®3042 is a high performance low dropout linear regulator featuring LTC’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive RF applications. Designed as a precision current reference followed by a high performance voltage buffer, the LT3042 can be easily paralleled to further reduce noise, increase output current and spread heat on the PCB.

The device supplies 200mA at a typical 350mV dropout voltage. Operating quiescent current is nominally 2mA and drops to <<1μA in shutdown. The LT3042’s wide output voltage range (0V to 15V) while maintaining unitygain 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.

The LT3042 is stable with a minimum 4.7μF ceramic output capacitor. Built-in protection includes reverse battery protection, reverse current protection, internal current limit with foldback and thermal limit with hysteresis. The LT3042 is available in thermally enhanced 10-Lead MSOP and 3mm × 3mm DFN packages.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LT3042EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3042EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3042EMSE#PBF MS-10E MSE E 05-08-1664 Yes
LT3042EMSE#TRPBF MS-10E MSE E 05-08-1664 Yes
LT3042HDD#PBF 3x3 DFN-10 DD H 05-08-1699 Yes
LT3042HDD#TRPBF 3x3 DFN-10 DD H 05-08-1699 Yes
LT3042HMSE#PBF MS-10E MSE H 05-08-1664 Yes
LT3042HMSE#TRPBF MS-10E MSE H 05-08-1664 Yes
LT3042IDD#PBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3042IDD#TRPBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3042IMSE#PBF MS-10E MSE I 05-08-1664 Yes
LT3042IMSE#TRPBF MS-10E MSE I 05-08-1664 Yes
LT3042MPDD#PBF 3x3 DFN-10 DD MP 05-08-1699 Yes
LT3042MPDD#TRPBF 3x3 DFN-10 DD MP 05-08-1699 Yes
LT3042MPMSE#PBF MS-10E MSE MP 05-08-1664 Yes
LT3042MPMSE#TRPBF MS-10E MSE MP 05-08-1664 Yes

LT3042 Package Drawing
LT3042 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LT3042EDD#PBF 3x3 DFN-10 E $3.22 $2.25 Yes
LT3042EDD#TRPBF 3x3 DFN-10 E $2.31 Yes
LT3042EMSE#PBF MS-10E E $3.22 $2.25 Yes
LT3042EMSE#TRPBF MS-10E E $2.31 Yes
LT3042HDD#PBF 3x3 DFN-10 H $4.00 $2.80 Yes
LT3042HDD#TRPBF 3x3 DFN-10 H $2.86 Yes
LT3042HMSE#PBF MS-10E H $4.00 $2.80 Yes
LT3042HMSE#TRPBF MS-10E H $2.86 Yes
LT3042IDD#PBF 3x3 DFN-10 I $3.57 $2.50 Yes
LT3042IDD#TRPBF 3x3 DFN-10 I $2.56 Yes
LT3042IMSE#PBF MS-10E I $3.57 $2.50 Yes
LT3042IMSE#TRPBF MS-10E I $2.56 Yes
LT3042MPDD#PBF 3x3 DFN-10 MP $8.29 $5.80 Yes
LT3042MPDD#TRPBF 3x3 DFN-10 MP $5.86 Yes
LT3042MPMSE#PBF MS-10E MP $8.29 $5.80 Yes
LT3042MPMSE#TRPBF MS-10E MP $5.86 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC2246B LT3042EDD Demo Board | Ultralow Noise, Ultrahigh PSRR RF LDO, 3.8V ≤ VIN ≤ 20V, VOUT = 3.3V @ 200mA $150.00
DC2429A LT3042 Low Noise PLL/VCO Power Supply Board with Onboard 100MHz Reference Frequency $150.00
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Click here to view our complete list of demo boards


  • RF Power Supplies: PLLs, VCOs, Mixers, LNAs
  • Very Low Noise Instrumentation
  • High Speed/High Precision Data Converters
  • Medical Applications: Imaging, Diagnostics
  • Precision Power Supplies
  • Post-Regulator for Switching Supplies

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