LTC3542 - 500mA, 2.25MHz Synchronous Step-Down DC/DC Converter


  • High Efficiency: Up to 96%
  • High Peak Switch Current: 1000mA
  • Low Output Ripple (<20mVP-P Typical) Burst Mode Operation: Only 26µA
  • Very Low Quiescent Current: Only 26µA
  • 2.5V to 5.5V Input Voltage Range
  • 2.25MHz Constant Frequency Operation
  • 1MHz to 3MHz External Frequency Synchronization
  • Low Dropout Operation: 100% Duty Cycle
  • No Schottky Diode Required
  • Internal Soft-Start Limits Inrush Current
  • 0.6V Reference Allows Low Output Voltages
  • Shutdown Mode Draws <1µA Supply Current
  • ±2% Output Voltage Accuracy
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Overtemperature Protected
  • Available in 6-Lead 2mm × 2mm DFN and Small TSOT

Typical Application

LTC3542 Typical Application
LTC3542 Typical Application


The LTC3542 is a high efficiency monolithic synchronous buck converter using a constant frequency, current mode architecture. Supply current during operation is only 26µA, dropping to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3542 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. The output voltage is adjustable from 0.6V to VIN. Internal power switches are optimized to provide high efficiency and eliminate the need for an external Schottky diode.

Switching frequency is internally set at 2.25MHz, allowing the use of small surface mount inductors and capacitors, and it can synchronize to an external clock signal with a frequency range of 1MHz to 3MHz through the MODE/ SYNC pin. The LTC3542 is specifically designed to work well with ceramic output capacitors, achieving very low output voltage ripple and a small PCB footprint.

The LTC3542 can be configured for the power saving Burst Mode Operation. For reduced noise and RF interference, the MODE/SYNC pin can be configured for pulse skipping operation.


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
LTC3542EDC#PBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LTC3542EDC#TRMPBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LTC3542EDC#TRPBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LTC3542ES6#PBF SOT-23 S6 E 05-08-1636 Yes
LTC3542ES6#TRMPBF SOT-23 S6 E 05-08-1636 Yes
LTC3542ES6#TRPBF SOT-23 S6 E 05-08-1636 Yes
LTC3542IDC#PBF 2x2 DFN-6 DC6 I 05-08-1703 Yes
LTC3542IDC#TRMPBF 2x2 DFN-6 DC6 I 05-08-1703 Yes
LTC3542IDC#TRPBF 2x2 DFN-6 DC6 I 05-08-1703 Yes
LTC3542IS6#PBF SOT-23 S6 I 05-08-1636 Yes
LTC3542IS6#TRMPBF SOT-23 S6 I 05-08-1636 Yes
LTC3542IS6#TRPBF SOT-23 S6 I 05-08-1636 Yes

LTC3542 Package Drawing
LTC3542 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
LTC3542EDC#PBF 2x2 DFN-6 E $2.29 Yes
LTC3542EDC#TRMPBF 2x2 DFN-6 E $2.34 $1.65 Yes
LTC3542EDC#TRPBF 2x2 DFN-6 E $2.29 $1.60 Yes
LTC3542ES6#PBF SOT-23 E $2.29 Yes
LTC3542ES6#TRMPBF SOT-23 E $2.34 $1.65 Yes
LTC3542ES6#TRPBF SOT-23 E $2.29 $1.60 Yes
LTC3542IDC#PBF 2x2 DFN-6 I $3.00 Yes
LTC3542IDC#TRMPBF 2x2 DFN-6 I $3.00 $2.15 Yes
LTC3542IDC#TRPBF 2x2 DFN-6 I $3.00 $2.10 Yes
LTC3542IS6#PBF SOT-23 I $3.00 Yes
LTC3542IS6#TRMPBF SOT-23 I $3.00 $2.15 Yes
LTC3542IS6#TRPBF SOT-23 I $3.00 $2.10 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
DC993A LTC3542EDC Demo Board | 2.5 ≤ VIN ≤ 5.5V, VOUT = 1.2V/1.5V/1.8V @ 500mA $75.00
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