Analog Devices Inc. LT3120 Monolithic Buck-Boost Converter

Analog Devices Inc. LT3120 Monolithic Buck-Boost Converter is a high efficiency 26V monolithic buck-boost converter. Extensive feature integration and very low resistance internal power switches minimize the total solution footprint for even the most demanding applications. A proprietary 4-switch PWM architecture provides seamless low noise operation from input voltages above, equal to, or below the output voltage.

External frequency programming, as well as synchronization using an internal PLL, enable operation over a wide switching frequency range of 400kHz to 2MHz. The wide 2.5V to 26V input range is well suited for operation from unregulated power sources, including battery stacks and backup capacitors. After start-up, the operation is possible with input voltages as low as 500mV.

Other features include output short-circuit protection, thermal overload protection, less than 3μA shutdown current, a Power Good indicator, Burst Mode operation, and maximum power point control. The Analog Devices LT3120 is offered in a thermally enhanced 28-lead 4mm × 5mm LQFN package.


  • 2.5V to 26V input voltage range
  • 0.8V to 24V output voltage range
  • High output current
    • 6.5A with VOUT = 5V, VIN > 6V
    • 3A with VOUT = 5V, VIN = 3V
    • 6.5A with VOUT = 12V, VIN > 14V
    • 4 A with VOUT = 12V, VIN = 9V
  • Ultra-low noise Buck-Boost architecture
  • Programmable output current limit
  • 400kHz to 2MHz programmable frequency range
  • Accurate enable comparator threshold
  • Burst Mode® operation, no-load IQ = 35μA
  • Current mode control
  • External clock synchronization
  • Maximum power point control
  • 28-lead 4mm × 5mm LQFN package


  • RF power supply
  • USB power delivery
  • System backup power supply
  • 1-cell to 5-cell lithium battery-powered products
  • Wide input range power supply
  • Lead-acid to 12V regulator

Typical Application

Application Circuit Diagram - Analog Devices Inc. LT3120 Monolithic Buck-Boost Converter
Published: 2021-06-24 | Updated: 2022-03-11