MAX1649是Maxim美信半导体公司的一款DC-DC开关调节器产品，MAX1649是5V/3.3V或可调、高效率、低压差、降压型DC-DC控制器，本站介绍了MAX1649的封装应用图解、特点和优点、功能等，并给出了与MAX1649相关的Maxim元器件型号供参考。
MAX1649 - 5V/3.3V或可调、高效率、低压差、降压型DC-DC控制器 - DC-DC开关调节器 - 高效降压控制器，工作在4节至8节电池 - 美信半导体
The MAX1649/MAX1651 BiCMOS, step-down, DC-DC switching controllers provide high efficiency over loads ranging from 1mA to more than 2.5A. 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). Dropout performance down to 300mV is provided by a high switch duty cycle (96.5%) and a low current-sense threshold (110mV).
A high switching frequency (up to 300kHz) allows these devices to use miniature external components.
The MAX1649/MAX1651 have dropout voltages less than 0.3V at 500mA and accept input voltages up to 16V. Output voltages are preset at 5V (MAX1649), or 3.3V (MAX1651). They 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 12.5W. 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.
