Rapid recovery circuit
AssigneePanasonic Corporation
InventorsMichiko Tokumaru, Heiji Ikoma
Life of this patent
Estimating the term…
Abstract
When a semiconductor circuit, in which a stabilizing capacitor 2 for stabilizing a reference voltage Vbias is connected to a reference voltage terminal RT, recovers from a power down state to an operational state, a current mirror circuit 40 provides current mirroring of a current Ia of a first current path Ph1, which generates an OFF threshold voltage ref1 of a hysteresis comparator 1, to generate a current Ib of a second current path Ph2, which generates the reference voltage Vbias. The reference voltage Vbias is input to the comparator 1 as an input voltage vin. When the reference voltage Vbias becomes equal to the OFF threshold voltage ref1, the comparator 1 immediately stops the charging of the stabilizing capacitor 2 by a current source I1.
Claims31
A rapid recovery circuit connected with a semiconductor circuit including a reference voltage terminal and a stabilizing capacitor connected with the reference voltage terminal to stabilize a reference voltage of the reference voltage terminal, the rapid recovery circuit comprising:
- a current source for charging the stabilizing capacitor;
- a comparator which charges the stabilizing capacitor by using the current source when the semiconductor circuit recovers from a power down state to a normal operational state, and stops the charging of the stabilizing capacitor by the current source when the reference voltage of the reference voltage terminal approaches a desired reference voltage as a result of the charging;
- and
- a bias circuit,
- wherein the bias circuit includes
- a first current path for generating a threshold voltage according to which the comparator stops the charging of the stabilizing capacitor by the current source;
- a second current path for generating the reference voltage of the reference voltage terminal;
- and
- a current mirror circuit for providing current mirroring of a current of the first current path to the second current path.
A rapid recovery circuit connected with a semiconductor circuit including a reference voltage terminal and a stabilizing capacitor connected with the reference voltage terminal to stabilize a reference voltage of the reference voltage terminal, the rapid recovery circuit comprising:
- a current source for charging the stabilizing capacitor;
- a comparator which charges the stabilizing capacitor by using the current source when the semiconductor circuit recovers from a power down state to a normal operational state, and stops the charging of the stabilizing capacitor by the current source when the reference voltage of the reference voltage terminal approaches a desired reference voltage as a result of the charging;
- and
- a bias circuit,
- wherein the bias circuit includes
- a first current path for generating a predetermined voltage;
- a second current path for generating the reference voltage of the reference voltage terminal;
- a current mirror circuit for providing current mirroring of a current of the first current path to the second current path;
- a first auxiliary current mirror circuit for providing current mirroring of the current of the first current path, and a second auxiliary current mirror circuit for providing current mirroring of a current of the second current path, the first and second auxiliary current mirror circuits sharing a part of the current mirror circuit;
- and
- two resistance elements through which the respective currents generated by the current mirroring by the first and second auxiliary current mirror circuits pass;
- and
- two voltages generated by the two resistance elements are used as an input voltage to the comparator and as a threshold voltage according to which the comparator stops the charging of the stabilizing capacitor by the current source.
A rapid recovery circuit connected with a semiconductor circuit including a reference voltage terminal and a stabilizing capacitor connected with the reference voltage terminal to stabilize a reference voltage of the reference voltage terminal, the rapid recovery circuit comprising:
- a current source for charging the stabilizing capacitor;
- and
- a comparator which charges the stabilizing capacitor by using the current source when the semiconductor circuit recovers from a power down state to a normal operational state, and stops the charging of the stabilizing capacitor by the current source when the reference voltage of the reference voltage terminal approaches a desired reference voltage as a result of the charging,
- wherein the current source includes first and second current sources;
- and
- when the comparator charges the stabilizing capacitor by using the first and second current sources, the comparator controls the first and second current sources in such a manner that the first and second current sources are used at first, and thereafter the first current source is stopped to use only the second current source.
A rapid recovery circuit connected with a semiconductor circuit including a reference voltage terminal and a stabilizing capacitor connected with the reference voltage terminal to stabilize a reference voltage of the reference voltage terminal, the rapid recovery circuit comprising:
- a current source for charging the stabilizing capacitor;
- and
- a comparator which charges the stabilizing capacitor by using the current source when the semiconductor circuit recovers from a power down state to a normal operational state, and stops the charging of the stabilizing capacitor by the current source when the reference voltage of the reference voltage terminal approaches a desired reference voltage as a result of the charging,
- wherein the current source is composed of a variable current source whose output current is variable;
- and
- the variable current source receives the reference voltage of the reference voltage terminal and is configured so that the value of the output current thereof decreases as the reference voltage approaches the desired reference voltage.
A rapid recovery circuit connected with a semiconductor circuit including a reference voltage terminal and a stabilizing capacitor connected with the reference voltage terminal to stabilize a reference voltage of the reference voltage terminal, the rapid recovery circuit comprising:
- a current source for charging the stabilizing capacitor;
- a comparator which charges the stabilizing capacitor by using the current source when the semiconductor circuit recovers from a power down state to a normal operational state, and stops the charging of the stabilizing capacitor by the current source when the reference voltage of the reference voltage terminal approaches a desired reference voltage as a result of the charging;
- and
- a forceful stopping means for controlling operation of the current source or of the comparator to forcefully stop the charging of the stabilizing capacitor by the current source when a predetermined amount of time has elapsed since the semiconductor circuit starts recovering to the normal operational state.
Dependencies are inferred from the claim text.