Low-drop voltage regulator
First Claim
1. A low-drop voltage regulator comprising an input terminal receiving an input voltage;
- an output terminal supplying an output voltage;
a first power switch connected between said input and output terminals;
a capacitive storage element connected to said input terminal via a one-way switch producing a standby voltage;
a second power switch connected between said capacitive element and said output terminal; and
a regulating element connected to said output terminal and said power switches, said regulating element detecting said output voltage and controlling said power switches in such a manner as to maintain said output voltage constant;
characterized by the fact that, between said regulating element and said power switches, there is provided a drive device also connected to said input terminal and said capacitive element;
said drive device comprising means for keeping both said power switches on as long as said input voltage remains above a first and second predetermined threshold value;
means for turning off said second switch when said input voltage is higher than said standby voltage and below said first threshold value; and
means for turning off said first switch when said input voltage is lower than said standby voltage and below said second threshold value.
1 Assignment
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Accused Products
Abstract
A voltage regulator comprising a first power switch connected between the input terminal and output terminal; a storage condenser connected to the input terminal via a one-way switch; a second power switch connected between the condenser and the input terminal; and a regulating element connected to the output terminal and driving the power switches in such a manner as to maintain the output voltage constant. For better distributing electric and thermal stress and improving the reliability and working life of the regulator by reducing the interference caused by switching of the two power switches, a drive device is provided between the regulating element and the switches for detecting the input voltage and the voltage of the condenser, and keeping both switches on as long as the input voltage is above two given thresholds, turning off the second switch when the input voltage is higher than the condenser voltage and below the first threshold, and turning off the first switch when the input voltage is lower than the condenser voltage and below the second threshold.
27 Citations
9 Claims
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1. A low-drop voltage regulator comprising an input terminal receiving an input voltage;
- an output terminal supplying an output voltage;
a first power switch connected between said input and output terminals;
a capacitive storage element connected to said input terminal via a one-way switch producing a standby voltage;
a second power switch connected between said capacitive element and said output terminal; and
a regulating element connected to said output terminal and said power switches, said regulating element detecting said output voltage and controlling said power switches in such a manner as to maintain said output voltage constant;
characterized by the fact that, between said regulating element and said power switches, there is provided a drive device also connected to said input terminal and said capacitive element;
said drive device comprising means for keeping both said power switches on as long as said input voltage remains above a first and second predetermined threshold value;
means for turning off said second switch when said input voltage is higher than said standby voltage and below said first threshold value; and
means for turning off said first switch when said input voltage is lower than said standby voltage and below said second threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- an output terminal supplying an output voltage;
Specification