LTC1877 - High Efficiency Monolithic Synchronous Step-Down Regulator


  • High Efficiency: Up to 95%
  • Very Low Quiescent Current: Only 10μA During Operation
  • 600mA Output Current at VIN = 5V
  • 2.65V to 10V Input Voltage Range
  • 550kHz Constant-Frequency Operation
  • No Schottky Diode Required
  • Low Dropout Operation: 100% Duty Cycle
  • Synchronizable from 400kHz to 700kHz
  • Selectable Burst Mode® Operation or Pulse-Skipping Mode
  • 0.8V Reference Allows Low Output Voltages
  • Shutdown Mode Draws < 1μA Supply Current
  • ±2% Output Voltage Accuracy
  • Current Mode Control for Excellent Line and Load Transient Response
  • Overcurrent and Overtemperature Protected
  • Available in 8-Lead MSOP Package

Typical Application

LTC1877 Typical Application
LTC1877 Typical Application


The LTC1877 s a high efficiency monolithic synchronous buck regulator using a constant-frequency, current mode architecture. Supply current during operation is only 10μA and drops to < 1μA in shutdown. The 2.65V to 10V input voltage range makes the LTC1877 ideally suited for both single and dual Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.

Switching frequency is internally set at 550kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications the LTC1877 can be externally synchronized from 400kHz to 700kHz. Burst Mode operation is inhibited during synchronization or when the SYNC/MODE pin is pulled low, preventing low frequency ripple from interfering with audio circuitry.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.8V feedback reference voltage. The LTC1877 is available in a space saving 8-lead MSOP package. Lower input voltage applications (less than 7V abs max) should refer to the LTC1878 data sheet.


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
LTC1877EMS8#PBF MS-8 MS8 E 05-08-1660 Yes
LTC1877EMS8#TRPBF MS-8 MS8 E 05-08-1660 Yes
LTC1877IMS8#PBF MS-8 MS8 I 05-08-1660 Yes
LTC1877IMS8#TRPBF MS-8 MS8 I 05-08-1660 Yes

LTC1877 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
LTC1877EMS8#PBF MS-8 E $3.43 $2.90 Yes
LTC1877EMS8#TRPBF MS-8 E $2.96 Yes
LTC1877IMS8#PBF MS-8 I $4.87 $3.41 Yes
LTC1877IMS8#TRPBF MS-8 I $3.47 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
DC290A-A LTC1877EMS8 Demo Board | 2.65V to 10V Input, 1.5V to 3.3Vout @ 600mA $100.00
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Click here to view our complete list of demo boards


  • Cellular Telephones
  • Wireless Modems
  • Personal Information Appliances
  • Portable Instruments
  • Distributed Power Systems
  • Battery-Powered Equipment

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