LTC3620 - Ultralow Power 15mA Synchronous Step-Down Switching Regulator


  • High Efficiency: Up to 95%
  • Maximum Current Output: 15mA
  • Externally Programmable Frequency Clamp with Internal 50kHz Default Minimizes Audio Noise
  • 18μA IQ Current
  • 2.9V to 5.5V Input Voltage Range
  • Low-Battery Detection
  • 0.6V Reference Allows Low Output Voltages
  • Shutdown Mode Draws <1μA Supply Current
  • 2.8V Undervoltage Lockout
  • Unique Low Noise Control Architecture
  • Internal Power MOSFETs
  • No Schottky Diodes Required
  • Internal Soft-Start
  • Tiny 2mm × 2mm 8-Lead DFN Package

Typical Application

LTC3620 Typical Application
LTC3620 Typical Application
LTC3620 Typical Application


The LTC®3620 is a high efficiency, synchronous buck regulator, suitable for very low power, very small footprint applications powered by a single Li-Ion battery.

The internal synchronous switches increase efficiency and eliminate the need for external Schottky diodes. Low output voltages are easily supported by the 0.6V feedback reference voltage. The LTC3620-1 option is internally programmed to provide a 1.1V output.

The LTC3620 uses a unique variable frequency architecture to minimize power loss and achieve high efficiency. The switching frequency is proportional to the load current, and an internal frequency clamp forces a minimum switching frequency at light loads to minimize noise in the audio range. The user can program the frequency of this clamp by applying an external clock to the FMIN/MODE pin.

The battery status output, LOBATB, indicates when the input voltage drops below 3V. To help prevent damage to the battery, an undervoltage lockout (UVLO) circuit shuts down the part if the input voltage falls below 2.8V.

The LTC3620 is available in a low profile, 2mm × 2mm 8-lead DFN package.


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
LTC3620EDC-1#PBF 2x2 DFN-8 DC8 E 05-08-1719 Yes
LTC3620EDC-1#TRMPBF 2x2 DFN-8 DC8 E 05-08-1719 Yes
LTC3620EDC-1#TRPBF 2x2 DFN-8 DC8 E 05-08-1719 Yes
LTC3620EDC#PBF 2x2 DFN-8 DC8 E 05-08-1719 Yes
LTC3620EDC#TRMPBF 2x2 DFN-8 DC8 E 05-08-1719 Yes
LTC3620EDC#TRPBF 2x2 DFN-8 DC8 E 05-08-1719 Yes

LTC3620 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
LTC3620EDC-1#PBF 2x2 DFN-8 E $2.79 Yes
LTC3620EDC-1#TRMPBF 2x2 DFN-8 E $2.79 $2.00 Yes
LTC3620EDC-1#TRPBF 2x2 DFN-8 E $2.79 $1.95 Yes
LTC3620EDC#PBF 2x2 DFN-8 E $2.79 Yes
LTC3620EDC#TRMPBF 2x2 DFN-8 E $2.79 $2.00 Yes
LTC3620EDC#TRPBF 2x2 DFN-8 E $2.79 $1.95 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
DC1460A LTC3620EDC Demo Board | 2.9V ≤ VIN ≤ 5.5V, Vout = 1.1V/1.2V/1.8V @ 15mA $75.00
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Click here to view our complete list of demo boards


  • Hearing Aids
  • Wireless Headsets
  • Li-Ion Cell Applications
  • Button Cell Replacement

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Design Tools


LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

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