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US 4,543,539 AGranted
Amplifier
AssigneeHitachi, Ltd.
InventorsKunio Seki, Ritsuji Takeshita
Life of this patent
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Abstract
An amplifier comprises an amplifier circuit for amplifying an input signal and a supply voltage detector for controlling the operation of the amplifier circuit. The supply voltage detector has hysteresis characteristics as to a first threshold voltage and a second threshold voltage which are different from each other in order to detect the magnitudes of the supply voltage. The amplifying operation of the amplifier circuit is controlled as to the start-up and turn-off operation thereof by an output signal of the supply voltage detector.
Claims14
An amplifier comprising:
- (a) an amplifier circuit including means for amplifying an input signal while a power supply voltage is applied thereto from a power supply voltage terminal;
- (b) power supply voltage detector means connected to said power supply voltage terminal and having a hysteresis detecting characteristic as to a first threshold level and a second threshold level, wherein said first threshold level is at a higher level than said second threshold level;
- and
- (c) means connected to said power supply voltage detector means and said amplifier circuit for controlling said amplifying means to amplify said input signal, wherein the amplifying operation of said amplifying means is started by said control means when said power supply voltage becomes higher than said first threshold level during a rise of said power supply voltage, and wherein said amplifying operation of said amplifying means is stopped by said control means when said power supply voltage becomes lower than said second threshold level during a fall of said power supply voltage.
1 more element
An amplifier comprising:
- (a) an amplifier circuit including means for amplifying an input signal while a power supply voltage is applied thereto from a power supply voltage terminal;
- and
- (b) power supply voltage detector means connected to said power supply voltage terminal for controlling the operation of said amplifying means and having a hysteresis detecting characteristic as to a first threshold level and a second threshold level, wherein said first threshold level is higher than said second threshold level, wherein the amplifying operation of said input signal by said amplifying means is started by the output of said detector means when said power supply voltage exceeds said first threshold level as said power supply voltage is increasing, and wherein said amplifying operation of said input signal by said amplifying means is stopped by the output of said detector means when said power supply voltage becomes less than said second threshold level as said power supply voltage is falling.
Dependencies are inferred from the claim text.