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 120µA 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 0.1µA) 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.