Inverse voltage-to-current conversion circuit
AssigneeDiodes Incorporated
InventorWei Wu
Life of this patent
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Abstract
An inverse voltage-to-current conversion circuit for providing a current that is inversely related to an input voltage is disclosed. A first input terminal and a second input terminal receives the input voltage between the first and the second input terminals. A voltage-to-time converter circuit provides a time indicator pulse signal with a pulse width related to inverse magnitude of the input voltage. A time-to-voltage converter circuit provides a voltage indicator signal having a magnitude based on the pulse width of the time indicator pulse signal. A voltage-to-current converter circuit provides a current indicator signal having a magnitude proportional to the voltage indicator signal—the current indicator signal being inversely related to the magnitude of the input voltage.
Claims15
An inverse voltage-to-current conversion circuit for providing a current that is inversely related to an input voltage, comprising:
- a first input terminal and a second input terminal for receiving the input voltage between the first and the second input terminals;
- a voltage-to-time converter circuit for providing a time indicator pulse signal with a pulse width related to inverse magnitude of the input voltage, wherein the voltage-to-time converter circuit comprises a first capacitor and a latch outputting the time indicator pulse signal with the pulse width, the pulse width being a charging time of the first capacitor, and the time indicator pulse signal switching from logic high to logic low when a voltage across the first capacitor reaches a reference voltage;
- a time-to-voltage converter circuit for providing a voltage indicator signal having a magnitude based on the pulse width of the time indicator pulse signal;
- and
- a voltage-to-current converter circuit for providing a current indicator signal having a magnitude proportional to the voltage indicator signal, the current indicator signal being inversely related to the magnitude of the input voltage.
A method for producing a current that is inversely proportional to a first voltage, comprising:
- sensing a first voltage across a first terminal and a second terminal;
- forming, by a voltage-to-time converter comprising a first capacitor and a latch, a time indicator pulse signal with a pulse width inversely related to a magnitude of the first voltage, wherein forming the time indicator pulse signal comprises:
- charging the first capacitor;
- and
- operating the latch to output the time indicator pulse signal, the pulse width being a charging time of the first capacitor, the time indicator pulse signal switching from logic high to logic low when a voltage across the first capacitor reaches a reference voltage;
- forming a second voltage having a magnitude based on a length of the time indicator pulse signal;
- and
- forming a current signal having a magnitude proportional to the second voltage.
Dependencies are inferred from the claim text.