Linear Technology Corporation announces the LTC3532, a synchronous buck-boost converter that can deliver up to 500mA of output current to a regulated output with inputs above, below or equal to the output. The topology incorporated in the LTC3532 provides a continuous transfer through all operating modes making it ideal for single cell Li-Ion or multi-cell alkaline/NiCad/NiMH applications which must maintain a constant output voltage even as the battery voltage declines below the output. In many cases this can add up to 20% or more battery run-time. The LTC3532's constant switching frequency offers low noise and is programmable up to 2MHz, minimizing the size of external components. The combination of tiny externals and a 3mm x 3mm DFN or MSOP-10 package provide a tiny solution footprint, typically required in handheld applications..
The LTC3532 includes two N-Channel MOSFETs and two P-Channel MOSFETs (0.33Ohm and 0.42Ohm respectively) to deliver efficiencies of up to 93%. Automatic BurstMode® operation allows the user to program the load current at which BurstMode initiates. BurstMode operation requires only 35uA of quiescent current while shutdown current is less than 1uA to further extend battery run-time. If the application is noise sensitive, the MODE pin can also be configured to provide forced continuous operation to reduce noise and any RF interference. Other features include soft-start, current limiting, thermal shutdown and output disconnect.
LTC3532EDD is available from stock in a 10-lead DFN package, whereas the LTC3532EMS is available in a 10-lead MSOP-10 package. Pricing for both versions starts at $2.35 ea for 1,000-piece quantities.
Summary of Features: LTC3532
Single Inductor
Regulated Output with Input Voltages Above, Below or Equal to the Output
Wide VIN Range: 2.4V to 5.5V
VOUT Range: 2.4V to 5.25V
Up to 500mA Peak Output Current
Synchronous Rectification: Up to 95% Efficiency
Manual or Programmable Automatic Burst Mode Operation
IQ <35 u A, ISD <1 u A
Output Disconnect in Shutdown
Programmable Oscillator: 300kHz to 2MHz
Pin Compatible with LTC3440
Small Thermally Enhanced 10-Lead (3mm x 3mm) DFN and 10-Lead MSOP Packages