Features

• Dual Synchronous Step-Up DC/DC Converters
• Delivers 3.3V at 200mA/100mA from one Alkaline/ NiMH Cell, or 3.3V at 400mA/200mA from Two Cells
• V_IN Start-Up Voltage: 700mV
• 0.5V to 5V V_IN Range After Start-Up
• 1.6V to 5.25V V_OUT Range
• Output Disconnect in Shutdown
• V_IN > V_OUT Operation
• 1.2MHz or 2.2MHz Operation
• Up to 94% Efficiency
• 12μA Quiescent Current in Burst Mode® Operation
• Inrush Current Limiting and Soft-Start
• Internal Synchronous Rectifiers
• Logic-Controlled Shutdown (< 2μA)
• Quick V_OUT Discharge (LTC3527-1)
• 16-Lead, 0.75mm × 3mm × 3mm QFN Package

Typical Application

Description

The LTC3527/LTC3527-1 are dual high efficiency, step-up DC/DC converters in a space saving 16-lead 3mm × 3mm QFN package. Battery life is maximized with a 700mV startup voltage and operation down to 500mV once started. The SHDN and PGOOD pins enable the converters to be sequenced or started together.

The LTC3527/LTC3527-1 limit inrush current during startup. Selectable 1.2MHz or 2.2MHz operation provides a choice between the highest efficiency or smallest solution footprint. The current mode PWM design is internally compensated reducing external parts count. Burst Mode operation or fixed frequency operation is selectable via the MODE pin. Anti-ring circuitry reduces EMI in discontinuous mode. This device also features thermal shutdown.

True output disconnect allows the output to be completely open in shutdown. The LTC3527-1 actively discharges V_OUT1 or V_OUT2 when its respective SHDN goes low. Quiescent current in shutdown is less than 2μA.