MAX649是Maxim美信半导体公司的一款DC-DC开关调节器产品，MAX649是5V/3.3V/3V或可调、高效率、低IQ、降压型DC-DC控制器，本站介绍了MAX649的封装应用图解、特点和优点、功能等，并给出了与MAX649相关的Maxim元器件型号供参考。
MAX649 - 5V/3.3V/3V或可调、高效率、低IQ、降压型DC-DC控制器 - DC-DC开关调节器 - 在较宽负载范围内具有低电源电流、高转换效率 - 美信半导体
The MAX649/MAX651/MAX652 BiCMOS, step-down DC-DC switching controllers provide high efficiency over three decades of load current. A unique, current-limited pulse-frequency-modulated (PFM) control scheme gives these devices the benefits of pulse-width-modulation (PWM) converters (high efficiency at heavy loads), while using only 100µA of supply current (vs. 2mA to 10mA for PWM converters). The result is high efficiency over loads ranging from 10mA to more than 2.5A.
These devices use miniature external components. Their high switching frequency (up to 300kHz) allows for less than 9mm diameter surface-mount inductors.
The MAX649/MAX651/MAX652 have dropout voltages less than 1V and accept input voltages up to 16.5V. Output voltages are preset at 5V (MAX649), 3.3V (MAX651), and 3V (MAX652). These controllers can also be adjusted to any voltage from 1.5V to the input voltage by using two resistors.
These step-down controllers drive external P-channel MOSFETs at loads greater than 10W. If less power is required, use the MAX639/MAX640/MAX653 step-down converters with on-chip FETs, which allow up to a 225mA load current.
