LT3991 - 55V, 1.2A Step-Down Regulator with 2.8μA Quiescent Current

Features
  • Ultralow Quiescent Current: 2.8μA IQ Regulating 12VIN to 3.3VOUT
  • Fixed Output Voltages: 3.3V, 5V 2.1μA IQ Regulating 12VIN
  • Low Ripple Burst Mode® Operation: Output Ripple < 15mVP-P
  • Wide Input Voltage Range: 4.3V to 55V
  • 1.2A Maximum Output Current
  • Adjustable Switching Frequency: 200kHz to 2MHz
  • Synchronizable Between 250kHz to 2MHz
  • Fast Transient Response
  • Accurate 1V Enable Pin Threshold
  • Low Shutdown Current: IQ = 700nA
  • Power Good Flag
  • Soft-Start CapabilityV
  • Internal Compensation
  • Saturating Switch Design: 0.44Ω On-Resistance
  • Output Voltage: 1.19V to 30V
  • Small Thermally Enhanced 10-Pin MSOP Package and (3mm × 3mm) DFN Packages
Typical Application

Applications
  • Automotive Battery Regulation
  • Power for Portable Products
  • Industrial Supplies
Packaging


Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT3991EDD#PBF3x3 DFN-10E$4.22$2.95
LT3991EDD#TRPBF3x3 DFN-10E$3.01
LT3991EMSE-3.3#PBFMS-10EE$4.22$2.95
LT3991EMSE-3.3#TRPBFMS-10EE$3.01
LT3991EMSE-5#PBFMS-10EE$4.22$2.95
LT3991EMSE-5#TRPBFMS-10EE$3.01
LT3991EMSE#PBFMS-10EE$4.22$2.95
LT3991EMSE#TRPBFMS-10EE$3.01
LT3991IDD#PBF3x3 DFN-10I$4.69$3.28
LT3991IDD#TRPBF3x3 DFN-10I$3.34
LT3991IMSE-3.3#PBFMS-10EI$4.69$3.28
LT3991IMSE-3.3#TRPBFMS-10EI$3.34
LT3991IMSE-5#PBFMS-10EI$4.69$3.28
LT3991IMSE-5#TRPBFMS-10EI$3.34
LT3991IMSE#PBFMS-10EI$4.69$3.28
LT3991IMSE#TRPBFMS-10EI$3.34
Demo Boards
Part NumberDescriptionPrice
DC1526ALT3991EMSE Demo Board | 55V, 1.2A, Step-Down Regulator with 2.8uA Quiescent Current$125.00
Datasheet
Reliability Data
LT Journal
Press Release
LTspice
Related Product
LT3991 - 55V, 1.2A Step-Down Regulator with 2.8μA Quiescent Current
LT3991 Package Drawing LT3991
LT3991 Package Drawing LT3991
R530 - Reliability Data
December 2009 - 1.2A Buck Converters Draw Only 2.8µA When Regulating Zero Load, Accept 38VIN or 55VIN 
55V、1.2A (IOUT) 降压型 DC/DC 转换器具有仅为 2.8uA 的静态电流
LT3991 Footprints and Symbols
LT3991 Demo Circuit - 55V 1.2A 2MHz Step-Down Regulator with 2.8µA Iq (12V to 3.3V @ 1.2A)