Power supply controller having low startup current

A power supply controller coupled to a load circuit that stores energy responsive to an input voltage and comprising the combination of:

• a voltage regulator operative when the input voltage exceeds a threshold value, and else being inoperative;
• means for applying the regulated reference voltage to drive the load circuit when the regulated reference voltage is provided;
• and
• means responsive to the absence of the regulated reference voltage for pulling down the output voltage using energy from the load.

A power supply controller for providing power to a load comprising the combination of:

• means for providing an input voltage;
• means for comparing the input voltage with a reference value;
• first driving means responsive to the means for comparing for driving the load when the input voltage exceeds the reference value;
• and
• second driving means for driving the load with power provided from the load temporarily into a power down mode when the input voltage is less than the reference value.

A method for controlling the providing of power to an output load, the method comprising:

• providing a regulated voltage to the load, wherein power is provided to the load;
• comparing a signal dependent upon the regulated voltage with a threshold;
• stopping the providing of the regulated voltage to the load when the signal crosses the threshold in a first direction;
• forcing the load into a power down mode by at least one switch at least partially temporarily powered by power drawn from the load.

A circuit for providing a regulated voltage to a load with a power down mode, the circuit comprising:

• a voltage regulator providing a switching signal and a regulated voltage at least some of the time;
• a comparator determining whether the regulated voltage is present;
• a first switch coupled to the load and responsive to the comparator such that the switch powers down the load when the regulated voltage is absent;
• and
• a second switch responsive to the switching signal and coupled to the first switch to keep the load powered down when the regulated voltage is absent.