Description

The MAX774/MAX775/MAX776 inverting switching regulators deliver high efficiency over three decades of load current. A unique current-limited, pulse-frequencymodulated (PFM) control scheme provides the benefits of pulse-width modulation (high efficiency with heavy loads), while using less than 100µA of supplycurrent (vs. 2mA to 10mA for PWM converters). The result is high efficiency over a wide range of loads.These ICs also use tiny external components; their high switching frequency (up to 300kHz) allows for less than 5mm diameter surface-mount magnetics.The MAX774/MAX775/MAX776 accept input voltages from 3V to 16.5V, and have preset output voltages of -5V, -12V, and -15V, respectively. Or, the output voltagecan be user-adjusted with two resistors. Maximum VIN - VOUT differential voltage is limited only by the break-down voltage of the chosen external switch transistor.These inverters use external P-channel MOSFET switches, allowing them to power loads up to 5W. If less power is required, use the MAX764/MAX765/MAX766 inverting switching regulators with on-board MOSFETs.ApplicationsBattery-Powered ApplicationsData CommunicationsHigh-Efficiency DC-DC ConvertersLCD Bias Generators