PT1311-High Efficiency Synchronous Boost DC/DC Converter  PDF文档下载
PT1311 是一款低启动电压，高效率的同步整流升压型直流-直流转换器。输入一节AA干电池能提供100mA/3.3V电流能力。1.2MHz开关频率减小了外围元器件尺寸,降低了系统成本。电流模式工作使其具备良好的电源和负载变化的响应，并具有逐开关电感峰值限流。内部环路补偿进一步减少了外围元器件。抗振铃电路减少了由非连续模式工作带来的EMI。PFM 模式提高了轻载时的转换效率。(微桥)输出短路保护避免了输出短路时对电池的损害。
GENERAL DESCRIPTION
The PT1311 is a high efficiency synchronous fixed frequency step-up DC/DC converter. The device is available in an adjustable version and fixed output voltages of 3.3V or 5.0V. Supply current during operation is only 25μA and drops to ≤1μA in shutdown. The 0.85V to 4.2V input voltage range makes the PT1311 ideally suited for single Li-Ion battery or single AA battery applications. Automatic Burst Mode operation increases efficiency at light loads, further extending battery life. Switching frequency is internally set at 1.2MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Anti-ringing control circuitry reduces EMI concerns by damping the inductor in DCM mode. The internal short protect circuitry can protect battery when output short to ground. The PT1311 is available in a SOT23-6 package.
FEATURES
High Efficiency: Up to 93%
Very Low Quiescent Current: Only 25μA During Operation
600mA Output Current
0.85V to 4.2V Input Voltage Range
1.2MHz Constant Frequency Operation
No Schottky Diode Required
Anti-ringing Control Minimizes EMI
Output Short Protect
Shutdown Mode Draws≤1μA Supply Current
Current Mode Operation for Excellent Line and Load Transient Response
Over temperature Protected
Feedback Voltage Auto Detect
SOT23-6 Package
APPLICATIONS
Li-ion Battery Chargers
USB Audio Devices
Wireless Mice
Digital Still Cameras
MP3/MP4 Players
Portable Instruments
TYPICAL APPLICATION DIAGRAM
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