Apparatus for charging a capacitor
First Claim
1. Apparatus for charging a storage capacitor includinga source of operating potential;
- a point of reference potential;
a plurality of stages arranged in order, each stage including capacitance means having first and second terminals,a first field effect transistor connected between the source of operating potential and the first terminal of the capacitance means, anda second field effect transistor connected between the second terminal of the capacitance means and the point of reference potential;
each of said stages except the last stage including a third field effect transistor connected between the second terminal of the capacitance means of the associated stage and the first terminal of the capacitance means of the following stage;
the last stage having a third field effect transistor connected between the second terminal of the capacitance means of the last stage and the source of operating potential;
means for coupling the first terminal of the capacitance means of the first stage to one terminal of the storage capacitor;
means for coupling the point of reference potential to the other terminal of the storage capacitor;
control means for applying first or second control signal conditions to said stages;
said first and second field effect transistors being operable in a high conduction condition and said third field effect transistors being operable in a relatively low conduction condition in response to said first control signal condition at said control means whereby each of said capacitance means is connected between said source of operating potential and said point of reference potential and becomes charged;
said first and second field effect transistors being operable in a low conduction condition and said third field effect transistors being operable in a relatively high conduction condition in response to said second control signal condition at said control means whereby the plurality of capacitance means are connected in series between said source of operating potential and said storage capacitor transferring a portion of the charges in the capacitance means into the storage capacitor;
said control means includinga control input terminal connected to the gate electrode of the second field effect transistor of the first stage for receiving said first or second control signal conditions, andmeans coupling the gate electrode of the second field effect transistor of each of said stages except the first stage to the preceding stage.
1 Assignment
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Accused Products
Abstract
An NMOS FET circuit for charging a storage capacitor to a voltage higher than the power supply voltage. The circuit includes several stages each including a capacitance and FET switches. In response to a high level control signal the FET'"'"'s in effect connect each capacitance between the supply voltage and ground to charge the capacitances. Then, in response to a low level control signal the FET'"'"'s in effect connect the capacitances in series between the supply voltage and the storage capacitor thus transferring a portion of the charges in the capacitances into the storage capacitor. The charge placed in the storage capacitor produces a voltage thereacross which is greater than the supply voltage.
70 Citations
10 Claims
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1. Apparatus for charging a storage capacitor including
a source of operating potential; -
a point of reference potential; a plurality of stages arranged in order, each stage including capacitance means having first and second terminals, a first field effect transistor connected between the source of operating potential and the first terminal of the capacitance means, and a second field effect transistor connected between the second terminal of the capacitance means and the point of reference potential; each of said stages except the last stage including a third field effect transistor connected between the second terminal of the capacitance means of the associated stage and the first terminal of the capacitance means of the following stage; the last stage having a third field effect transistor connected between the second terminal of the capacitance means of the last stage and the source of operating potential; means for coupling the first terminal of the capacitance means of the first stage to one terminal of the storage capacitor; means for coupling the point of reference potential to the other terminal of the storage capacitor; control means for applying first or second control signal conditions to said stages; said first and second field effect transistors being operable in a high conduction condition and said third field effect transistors being operable in a relatively low conduction condition in response to said first control signal condition at said control means whereby each of said capacitance means is connected between said source of operating potential and said point of reference potential and becomes charged; said first and second field effect transistors being operable in a low conduction condition and said third field effect transistors being operable in a relatively high conduction condition in response to said second control signal condition at said control means whereby the plurality of capacitance means are connected in series between said source of operating potential and said storage capacitor transferring a portion of the charges in the capacitance means into the storage capacitor; said control means including a control input terminal connected to the gate electrode of the second field effect transistor of the first stage for receiving said first or second control signal conditions, and means coupling the gate electrode of the second field effect transistor of each of said stages except the first stage to the preceding stage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification