The MAX1771 step-up switching controller provides 90% efficiency over a 30mA to 2A load. A unique current-limited pulse-frequency-modulation (PFM) control scheme gives this device the benefits of pulse-width-modulation (PWM) converters (high efficiency at heavy loads), while using less than 110µA of supply current (vs. 2mA to 10mA for PWM converters).
This controller uses miniature external components. Its high switching frequency (up to 300kHz) allows surface-mount magnetics of 5mm height and 9mm diameter. It accepts input voltages from 2V to 16.5V. The
output voltage is preset at 12V, or can be adjusted using two resistors.
The MAX1771 optimizes efficiency at low input voltages and reduces noise by using a single 100mV current-limit threshold under all load conditions. A family of similar devices, the MAX770-MAX773, trades some full-load efficiency for greater current-limit accuracy; they provide a 200mV current limit at full load, and switch to 100mV for light loads.
The MAX1771 drives an external N-channel MOSFET switch, allowing it to power loads up to 24W. If less power is required, use the MAX756/MAX757 or MAX761/MAX762 step-up switching regulators with on-board MOSFETs. An evaluation kit is available.
关键特性
应用/使用
90% Efficiency for 30mA to 2A Load Currents
Up to 24W Output Power
110µA (max) Supply Current
5µA (max) Shutdown Current
2V to 16.5V Input Range
Preset 12V or Adjustable Output Voltage
Current-Limited PFM Control Scheme
Up to 300kHz Switching Frequency
Evaluation Kit Available
电池供电应用
闪存编程
大功率射频功放电源
掌上电脑/手持终端
便携式通信装置
LCD正偏置发生器
Key Specifications:
Switch-Mode DC-DC Power Supplies
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.
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