Switching Regulator And Electronic Device Therewith
First Claim
1. A switching regulator comprising:
- an output switching element connected between an input terminal to which an input voltage is applied and an output terminal from which an output voltage is derived to be fed to a load;
an output feedback circuit generating an error voltage varying according to an error between an actual value of and a target value of the output voltage;
a switching control circuit turning on and off the output switching element based on the error voltage so that the error of the output voltage is reduced;
a short-circuit current protection circuit including;
a first comparator comparing with a predetermined first threshold voltage an output current reference voltage varying according to an output current to the load,the short-circuit current protection circuit generating, based on a comparison output signal from the first comparator, a short-circuit current protection signal instructing whether to drive the switching control circuit; and
a drive current generating circuit including;
a second comparator operating with a drive current lower than a drive current for the first comparator and comparing the error voltage with a predetermined second threshold voltage,the drive current generating circuit determining, based on a comparison output signal from the second comparator, whether to supply the drive current to the first comparator.
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Accused Products
Abstract
A switching regulator according to the invention includes: an output switching element; an output feedback circuit generating an error voltage (Verr) according to an error between an output voltage (Vout) and a target voltage; a switching control circuit turning on and off the output switching element based on the error voltage (Verr); a short-circuit current protection circuit that includes a first comparator (CMP1) comparing a reference voltage (Vs) commensurate with an output current (iout) with a first threshold voltage (Vth1) and that instructs, based on this comparison result, whether to drive the switching control circuit; and a drive current generating circuit that includes a second comparator (CMP2) comparing the error voltage (Verr) with a second threshold voltage (Vth2) and that determines, based on this comparison result, whether to supply a drive current (i1) to the first comparator (CMP1). With this configuration, it is possible to reduce the waste of electric power without spoiling the reliability of short-circuit current protection.
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Citations
4 Claims
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1. A switching regulator comprising:
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an output switching element connected between an input terminal to which an input voltage is applied and an output terminal from which an output voltage is derived to be fed to a load; an output feedback circuit generating an error voltage varying according to an error between an actual value of and a target value of the output voltage; a switching control circuit turning on and off the output switching element based on the error voltage so that the error of the output voltage is reduced; a short-circuit current protection circuit including; a first comparator comparing with a predetermined first threshold voltage an output current reference voltage varying according to an output current to the load, the short-circuit current protection circuit generating, based on a comparison output signal from the first comparator, a short-circuit current protection signal instructing whether to drive the switching control circuit; and a drive current generating circuit including; a second comparator operating with a drive current lower than a drive current for the first comparator and comparing the error voltage with a predetermined second threshold voltage, the drive current generating circuit determining, based on a comparison output signal from the second comparator, whether to supply the drive current to the first comparator. - View Dependent Claims (2, 3, 4)
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Specification