Microchip has announced a series of 750 kHz gated oscillator DC/DC Boost controllers that can deliver 5W of power to the load while consuming only 120&microA of quiescent current at no load. They can be used to generate the supply voltage for microcontrollers and other electronic loads from a battery supply or the bus voltages available in a system.

The MCP1650/51/52/53 series offers a range of features that includes low-battery detect, used to determine when the battery input voltage has fallen below a predetermined threshold. Other features include a low-power shutdown mode, (typically less than 0.1&microA) and a power-good indicator that monitors the output voltage, transitioning the voltage from a high impedance state to a low state capable of sinking up to 10mA if it drops below the regulated set point.

Peak-input current limiting prevents the current from becoming too high and damaging the external N-channel MOSFET. Output voltage is adjustable from 2.5V to over 100V. A choice of two undervoltage lockout voltages (2.0V or 2.55V) is available.

The internal oscillator operates at two different duty cycles , depending upon the level of the input voltage. These duty cycles limit peak currents and maximise power from low-voltage sources; meanwhile, the peak current limit reduces the noise and lowers the stress on the power train components.

Intended for space-limited designs, devices in the MCP165X series can operate over a wide input-voltage range (2.0V-5.5V) to accommodate multiple primary cell combinations or single cell Li-lon battery-powered applications in addition to 2.8V, 3.0V, 3.3V and 5.0V regulated input voltages. In addition to battery-operated equipment where supply voltages are often variable, due to charging and discharging, they are aimed at networking and computer applications, offering simple voltage step-up solutions that can be used as point-of-load regulators throughout a system.

Microchip Technology , Wokingham, Berks RG41 5TU, UK.
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