US 12,456,976 B2Granted

Switch circuit control

AssigneeTexas Instruments Incorporated

InventorSean Patrick McEnroe

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Abstract

In some examples, an apparatus includes a switch circuit, a charge circuit, and a shutoff circuit. The switch circuit is configured to control passage of a data signal having a frequency of less than about 10 kilohertz (kHz) from an input terminal to an output terminal, the switch circuit having a control terminal. The charge circuit is coupled to a voltage supply and the switch circuit, wherein the charge circuit is configured to harvest a portion of current flowing through the switch circuit between the input terminal and the output terminal to maintain a charge at the control terminal greater than a programmed amount in a first state of operation and prevent charge from leaking from the control terminal. The shutoff circuit is coupled to the switch circuit and configured to discharge the charge at the control terminal in a second state of operation.

Claims20

Dependent claims

An apparatus, comprising:

a shutoff circuit having an input and including a first transistor having a control terminal and first and second terminals;
a switch circuit including a second transistor having a control terminal and first and second terminals, the control terminal of the second transistor is coupled to the first terminal of the first transistor, and the first terminal of the second transistor is coupled to the second terminal of the first transistor;
a first capacitor having a first terminal coupled to a voltage terminal, and having a second terminal;
a second capacitor having a first terminal coupled to the second terminal of the first capacitor, and having a second terminal coupled to the second terminal of the first transistor and to the first terminal of the second transistor;
a first diode having a first anode and a first cathode, the first anode is coupled to the second terminal of the first capacitor and to the first terminal of the second capacitor, and the first cathode is coupled to the input of the shutoff circuit;
a second diode having a second anode and a second cathode, the second anode is coupled to the second terminal of the second capacitor, to the second terminal of the first transistor, and to the first terminal of the second transistor, and the second cathode is coupled to the first anode, to the second terminal of the first capacitor, and to the first terminal of the second capacitor;
and
a third diode having a third anode and a third cathode, the third anode is coupled to the second terminal of the first capacitor, to the first terminal of the second capacitor, to the first anode, and to the second cathode, and the third cathode is coupled to the control terminal of the second transistor and to the first terminal of the first transistor.

5 more elements

Dependencies are inferred from the claim text.