Time-to-voltage converter with extended output range
AssigneeSilicon Laboratories Inc.
InventorAaron J. Caffee
Life of this patent
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Abstract
A time-to-voltage converter includes a switched-capacitor circuit configured to charge an output node to a reset voltage level in a first interval of a conversion period and configured to shift a voltage on the output node from the reset voltage level to a shifted reset voltage level in a second interval of the conversion period. The time-to-voltage converter includes a current source selectively coupled to the output node. The current source is configured to provide a constant current to the output node in a third interval of the conversion period. The shifted reset voltage level is outside a voltage range defined by a first power supply voltage level on a first voltage reference node and a second power supply voltage level on a second voltage reference node.
Claims20
An apparatus comprising:
- a first voltage reference node;
- a second voltage reference node;
- and
- a time-to-voltage converter comprising:
- a switched-capacitor circuit configured to charge an output node to a reset voltage level in a first interval of a conversion period and configured to shift a voltage on the output node from the reset voltage level to a shifted reset voltage level in a second interval of the conversion period,
- wherein the shifted reset voltage level is outside a voltage range of the voltage on the output node defined by a first power supply voltage level on the first voltage reference node and a second power supply voltage level on the second voltage reference node.
A method for converting a time signal to a voltage signal, the method comprising:
- storing charge on a capacitor of a time-to-voltage converter to provide a reset voltage level on an output node of the time-to-voltage converter in a first interval of a time-to-voltage conversion;
- and
- shifting a voltage level of the output node from the reset voltage level to a shifted reset voltage level in a second interval of the time-to-voltage conversion,
- wherein the shifted reset voltage level is outside a voltage range of an output signal of the time-to-voltage converter defined by a first power supply voltage level on a first voltage reference node and a second power supply voltage level on a second voltage reference node.
Dependencies are inferred from the claim text.