The device’s topology provides a continuous transfer through all operating modes making it ideal for three- or four- cell Alkaline/NiCad/NiMH or single cell lithium applications which must maintain a constant output voltage even as the battery voltage declines below the output. In most cases this Buck-Boost DC/DC Converter can add up to 25% more battery run-time compared to a traditional SEPIC solution. The LTC3534’s constant 1MHz switching frequency ensures low noise while minimizing the size of external components. The combination of tiny externals and a 3mm x 5mm DFN (or SSOP-16) provide a tiny solution footprint, typically required in handheld applications.
The LTC3534 includes two N-Channel MOSFETs and two P-Channel MOSFETs (215mOhm/275mOhm and 260mOhm, respectively) to deliver efficiencies of up to 94%. Burst Mode operation requires only 25uA of quiescent current while shutdown current is less than 1uA, further extending battery run-time. If the application is noise sensitive, the PWM pin can also be configured to provide forced continuous operation to reduce noise and RF interference. Other features include soft-start, current limiting, thermal shutdown and output disconnect.
LTC3534EDD is available from stock in a 16-lead 3mm x 5mm DFN package, and the LTC3534EGN is available in a 16-lead SSOP package. Pricing for both versions is $3.15 each in 1,000 piece quantities.
Summary of Features: LTC3534:
Regulated Output with Input Voltages Above, Below or Equal to the Output;
2.4V to 7V Input & 1.8V to 7V Output Voltage Ranges;
5V VOUT at 500mA from 4 AA Cells;
Single Inductor;
Synchronous Rectification: Up to 94% Efficiency;
Burst Mode® Operation with 25uA IQ;
Output Disconnect in Shutdown;
1MHz Switching Frequency
<1uA Shutdown Current;
Small Thermally Enhanced 16-Lead (3mm × 5mm × 0.75mm) DFN & 16-Lead SSOP Packages.
