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US 8,552,791 B2Granted
Protected power switch with low current consumption
AssigneeDecicon, Inc.
InventorsVolkan Sahin, Murat Okyar, Hakan Ates Gurcan
Life of this patent
Estimating the term…
Abstract
Under-voltage, over-voltage, and temperature detectors disposed in a switching circuit are turned on periodically and in response to an oscillating signal having a low duty cycle. Accordingly, because the voltage and temperature detectors remain off for long durations, their operating currents, and thus the operating current of the switching circuit is substantially reduced. The switching circuit has a current limiting function which is disabled when the switch current is below a threshold value, thereby further decreasing the current consumption of the switching circuit at low switch current levels.
Claims23
A switching circuit comprising:
- an oscillator operative to generate an oscillating signal, said oscillating signal having on periods that are substantially shorter than its off periods;
- a detector responsive to an input signal and to the oscillating signal, said detector operating in a low-current mode during the off periods of the oscillating signal and operating in an active mode during the on periods of the oscillating signal, said detector generating a detect signal in response to a magnitude of the input signal in comparison to a threshold value when operating in the active mode;
- a memory element operable to store the detect signal;
- and
- a switch receiving the input signal and adapted to be turned off when said stored detect signal is in a first logic state and turned on when said stored detect signal is in a second logic state.
2 more elements
A switching circuit comprising:
- an oscillator operative to generate an oscillating signal, said oscillating signal having on periods that are substantially shorter than its off periods;
- a detector responsive to an input signal and to the oscillating signal, said detector operating in a low-current mode during the off periods of the oscillating signal and operating in an active mode during the on periods of the oscillating signal, said detector generating a detect signal in response to a magnitude of the input signal in comparison to a threshold value when operating in the active mode;
- a memory element operable to store the detect signal;
- a switch adapted to be turned off when said stored detect signal is in a first logic state and turned on when said stored detect signal is in a second logic state;
- wherein
- said input signal is a chip temperature;
- and
- said detect signal is generated in response to the chip temperature being higher than a threshold value.
5 more elements
A method of supplying current to a load, the method comprising:
- generating an oscillating signal, said oscillating signal having on periods that are substantially shorter than its off periods;
- operating a detector in a low-current mode during the off periods of the oscillating signal and in an active mode during the on periods of the oscillating signal;
- generating a detect signal by the detector during the on periods of the oscillating signal in response to a magnitude of an input signal in comparison to a threshold value;
- storing the detect signal;
- applying the input signal to a switch;
- turning on the switch to supply the current if the stored detect signal is in a first logic state;
- and
- turning off the switch so as not to supply the current if the stored detect signal is in a second logic state.
5 more elements
A switch comprising:
- a resistive element receiving an input voltage;
- a first transistor coupled to the resistive element;
- a comparator responsive to the resistive element and a threshold value, said comparator generating an output signal having a first value if a current flowing through the first transistor is detected as being smaller than a first threshold value, wherein the output signal of the comparator has a second value if the current is detected as being greater than the first threshold value;
- and
- an amplifier operative to be disabled in response to the first value of the output signal of the comparator, and to be enabled in response to the second value of the output signal of the comparator.
2 more elements
A method of controlling a current flowing through a transistor, the method comprising:
- generating a comparison signal having a first value if the current flowing through the transistor is detected as being smaller than a first threshold value, wherein the comparison signal has a second value if the current flowing through the transistor is detected as being greater than the first threshold value;
- disabling an amplifier in response to the first value of the comparison signal;
- and
- enabling the amplifier in response to the second value of the comparison signal.
1 more element
A method of supplying current to a load, the method comprising:
- generating an oscillating signal, said oscillating signal having on periods that are substantially shorter than its off periods;
- operating a detector in a low-current mode during the off periods of the oscillating signal and in an active mode during the on periods of the oscillating signal;
- generating a detect signal by the detector during the on periods of the oscillating signal in response to a magnitude of an input signal in comparison to a threshold value;
- storing the detect signal;
- turning on the switch to supply the current if the stored detect signal is in a first logic state;
- and
- turning off the switch so as not to supply the current if the stored detect signal is in a second logic state, wherein said input signal is a chip temperature and wherein said detect signal is generated in response to the chip temperature being higher than a threshold value.
4 more elements
Dependencies are inferred from the claim text.