Features

• Regulated Output with Input Above, Below or Equal to the Output
• Single Inductor
• Up to 90% Efficiency
• VIN Range: 1.8V to 5.5V
• 200mA at 3.3V_OUT from 3.6V Input
• 125mA at 3V_OUT from 2.5V Input
• Fixed V_OUT Versions (TSOT, DFN): 3.3V, 3V
• Adjustable V_OUT Version (DFN): 2V to 5V
• Burst Mode® Operation, No External Compensation
• Ultra Low Quiescent Current: 16μA, Shutdown Current <1μA
• Only 3 External Components Required
  (Fixed Voltage Versions)
• Short-Circuit Protection
• Output Disconnect in Shutdown
• Available in 6-Pin ThinSOT and 3mm × 3mm DFN Packages

Typical Application

Description

The LTC3531/LTC3531-3.3/LTC3531-3 are synchronous buck-boost DC/DC converters that operate from input voltages above, below or equal to the output voltage. The topology incorporated in the ICs provides a continuous transfer through all operating modes, making the product ideal for single cell Li-Ion and multicell alkaline or nickel applications. The converters operate in Burst Mode, minimizing solution footprint and component count as well as providing high conversion efficiency over a wide range of load currents.

The devices include two 0.5Ω N-channel MOSFET switches and two P-channel switches (0.5Ω, 0.8Ω). Quiescent current is typically 16μA, making the parts ideal for battery power applications. Other features include a <1uA shutdown current, current limiting, thermal shutdown and output disconnect. The parts are offered in a 6-pin ThinSOT package for fi xed voltage versions or a 3mm × 3mm DFN package for fixed and adjustable versions.