The MAX764/MAX765/MAX766 inverting switching regulators are highly efficient over a wide range of load currents, delivering up to 1.5W. A unique, current-limited, pulse-frequency-modulated (PFM) control scheme combines the benefits of traditional PFM converters with the benefits of pulse-width-modulated (PWM) converters. Like PWM converters, the MAX764/MAX765/MAX766 are highly efficient at heavy loads. Yet because they are PFM devices, they use less than 120μA of supply current (vs. 2mA to 10mA for a PWM device). The input voltage range is 3V to 16V. The output voltage is preset at -5V (MAX764), -12V (MAX765), or -15V (MAX766); it can also be adjusted from -1V to -16V using two external resistors (Dual Mode). The maximum operating VIN - VOUT differential is 20V. These devices use miniature external components; their high switching frequencies (up to 300kHz) allow for less than 5mm diameter surface-mount magnetics. A standard 47μH inductor is ideal for most applications, so no magnetics design is necessary. An internal power MOSFET makes the MAX764/MAX765/ MAX766 ideal for minimum component count, low- and medium-power applications. For increased output drive capability or higher output voltages, use the MAX774/MAX775/MAX776 or MAX1774, which drive an external power P-channel MOSFET for loads up to 5W.
Feature
- High Efficiency for a Wide Range of Load Currents
- 250mA Output Current
- 120μA Max Supply Current
- 5μA Max Shutdown Current
- 3V to 16V Input Voltage Range
- -5V (MAX764), -12V (MAX765), -15V (MAX766), or Adjustable Output from -1V to -16V
- Current-Limited PFM Control Scheme
- 300kHz Switching Frequency
- Internal, P-Channel Power MOSFET
Applications
- Battery-Powered Applications
- LAN Adapters
- LCD Bias Generators
- Portable Instrumentation
- Remote Data-Acquisition Systems