1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. Buck Regulator Plus LDO
  6. LTC3445


Features and Benefits

Buck Regulator
  • High Efficiency: Up to 93%
  • 600mA Output Current (VCC1 = 3V, VOUT = 1.3V)
  • Programmable Output Voltage: 0.85V to 1.55V
  • 2.5V to 5.5V Input Voltage Range
  • 1.5MHz Constant Frequency or Spread Spectrum Option
  • Soft-Start
  • Two LDO Regulators: 0.3V Dropout at 50mA
PowerPath Controller
  • Dynamically Regulates VCC BATT
  • Standard (100kHz) or Fast Mode (400kHz)
  • 24-Lead (4mm × 4mm) QFN Package

Product Details

The LTC3445 contains a high efficiency monolithic synchronous current mode buck regulator, two LDO regulators, a PowerPath controller and an I2C interface.

The buck regulator has a 6-bit programmable output range of 0.85V to 1.55V. Also, the buck regulator uses either a constant (1.5MHz) or a spread spectrum switching frequency. Using the spread spectrum option allows for a lower noise regulated output as well as low noise at the input. In addition, the regulated output voltage slew rate is programmable via the I2C interface.

The LTC3445 contains two LDO voltage regulators. The regulator output voltages are externally resistor programmable. Each LDO is capable of delivering up to 50mA.

The LTC3445 contains control circuitry (PowerPath) for automatic back-up battery selection. VBACKUP is typically a coin cell.

Typical supply current during operation is only 360µA and drops to 27µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3445 ideal for single Li-Ion battery-powered applications. Automatic Burst Mode® operation increases efficiency at light loads, further extending battery life.

Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, Spread Spectrum patent pending.


  • Intel’s Microprocessor Supply (PXA27X)
  • Portable Instruments

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (1)

Product Recommendations

LTC3445 Companion Parts

Recommended Related Parts

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
LTC3445EUF#PBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
LTC3445EUF#TRPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
Wafer Fabrication Data R415 Reliability Data

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Evaluation Boards

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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.