US 7,742,893 B2 · Calibration circuit for calibrating an adjustable capacitance of an integrated circuit having a time constant depending on said capacitance

Abstract

A calibration circuit calibrates an adjustable capacitance of a circuit having a time constant depending on the adjustable capacitance. The calibration circuit outputs a calibration signal carrying information for calibrating the capacitor and includes a calibration loop. The calibration circuit includes: a controllable capacitance unit suitable to receive a control signal and including at least one array of switched capacitors that can be activated by the control signal, the unit being such as to output a first signal characterized by a parameter depending on the amount of capacitance of the array activated by the control signal; a comparison unit suitable to receive the first signal to assess whether the parameter meets a preset condition and to output a comparison signal representative of the assessment result; a control and timing logic unit suitable to receive the comparison signal to change this control signal based on the comparison signal, characterized in that the first signal is a logic signal and the parameter is a time parameter of the first signal.

Claims17

Dependent claims

A calibration circuit for calibrating an adjustable capacitance of a circuit having a time constant depending on said adjustable capacitance, the calibration circuit being adapted to output a calibration signal having information to calibrate said adjustable capacitance, the calibration circuit comprising:

a calibration loop having:
a controllable capacitance unit adapted to receive a control signal and including at least one array of switched capacitors that can be activated by the control signal, the controllable capacitance unit being adapted to output a first signal representing a parameter depending on an amount of capacitance of the array activated by the control signal;
a comparison unit adapted to receive said first signal to assess whether said parameter meets a preset condition and to output a comparison signal representative of a result of said assessment;
a control and timing logic unit adapted to receive the comparison signal and to change the control signal based on said comparison signal,
wherein said first signal is a logic signal and said parameter is a time parameter of said first signal.

2 more elements

A system, comprising:

a circuit having an adjustable capacitance adapted to adjust a time constant of said circuit;
and
a calibration circuit coupled to said circuit having the adjustable capacitance and adapted to provide a calibration signal to said circuit to adjust said adjustable capacitance, the calibration circuit including:
a controllable capacitance unit to receive a control signal adapted to activate an amount of capacitance of the controllable capacitance unit, the controllable capacitance unit being adapted to output a first signal representing a time parameter that depends on an amount of capacitance of the array activated by the control signal;
a comparison unit coupled to said controllable capacitance unit to receive said first signal and adapted to assess whether said time parameter meets a condition and to output a comparison signal representative of a result of said assessment;
and
a control and timing logic unit coupled to said comparison unit and adapted to receive the comparison signal and to change the control signal based on said comparison signal,
wherein a value of said control signal after an end of a calibration cycle corresponds to a value of said calibration signal, provided by said control and timing logic unit to said circuit having the adjustable capacitance.

5 more elements

Dependencies are inferred from the claim text.

Calibration circuit for calibrating an adjustable capacitance of an integrated circuit having a time constant depending on said capacitance

Life of this patent

Calibration circuit for calibrating an adjustable capacitance of an integrated circuit having a time constant depending on said capacitance

Life of this patent

Abstract

Claims17