特点
Synchronous Rectification: Up to 96% Efficiency
True Output Disconnect
Inrush Current Limiting
Very Low Quiescent Current: 12μA
Up to 1.5A Continuous Output Current
Fixed Frequency Operation Up to 3MHz
0.5V to 4.5V Input Range
2.4V to 5.25V Adjustable Output Voltage
Guaranteed 1V Start-Up
Programmable Current Limit
Programmable Soft-Start
Synchronizable Oscillator
Manual or Automatic Burst Mode? Operation
Low-Battery Comparator
<1μA Shutdown Current
1.22V Reference Output Voltage
Small (4mm x 4mm) Thermally Enhanced QFN Package
典型应用
典型应用
描述
The LTC?3421 is a high efficiency, current mode, fixed frequency, step-up DC/DC converter with true output disconnect and inrush current limiting. The device includes a 0.10 Ohm N-channel MOSFET switch and a 0.14 Ohm P-channel synchronous rectifier. This product has the ability to simply program the output voltage, switching frequency, current limit, soft-start, Burst Mode threshold and loop compensation with external passive components.
Quiescent current is only 12μA during Burst Mode operation, maximizing battery life in portable applications. The oscillator frequency can be programmed up to 3MHz and can be synchronized to an external clock applied to the SYNC pin. An open-drain uncommitted low-battery comparator is included. The part maintains operation in applications with a secondary cell powering the output voltage during shutdown.
Other features include: 1μA shutdown, antiringing control, thermal limit and reference output.
The LTC3421 is available in a small 4mm x 4mm QFN package.