Time integrator and ΔΣ time-to-digital converter

A time integrator integrating time axis information represented by a phase difference between two signals, the time integrator comprising:

• a pulse generation circuit configured to convert a time difference between edges of two input signals to a difference between pulse widths of two pulse signals, and to output the two pulse signals;
• a load circuit having load characteristics changed by the two pulse signals;
• and
• an oscillation circuit coupled to the load circuit, and having an oscillation frequency changing in accordance with the load characteristics of the load circuit,
• wherein an output of the oscillation circuit is output as a result of time integration,
• the pulse generation circuit includes another pulse generation circuit;
• the load circuit includes another load circuit,
• another two signals are input to the another pulse generation circuit,
• each of the load circuits includes a plurality of variable capacitance circuits, each being configured to receive one or the other of the two pulse signals, and having a capacitance value varying in accordance with a logic level of the received pulse signal, and
• each of the oscillation circuits includes:
• an oscillator coupled to one(s) of the variable capacitance circuits receiving the one of the two pulse signals, having an oscillation frequency changing in accordance with a capacitance value(s) of the coupled variable capacitance circuit(s), and
• another oscillator coupled to another one(s) of the variable capacitance circuits receiving the other one of the two pulse signals, and having an oscillation frequency changing in accordance with a capacitance value(s) of the coupled variable capacitance circuit(s).

A time integrator integrating time axis information represented by a phase difference between two signals, the time integrator comprising:

• a pulse generation circuit configured to convert a time difference between edges of two input signals to a difference between pulse widths of two pulse signals, and to output the two pulse signals;
• a load circuit having load characteristics changed by the two pulse signals;
• and
• an oscillation circuit coupled to the load circuit, and having an oscillation frequency changing in accordance with the load characteristics of the load circuit,
• wherein an output of the oscillation circuit is output as a result of time integration,
• each of the load circuits includes a plurality of variable capacitance circuits, each being configured to receive one or the other of the two pulse signals, and having a capacitance value varying in accordance with a logic level of the received pulse signal, and
• each of the oscillation circuits includes an oscillator coupled to the plurality of variable capacitance circuits, and having an oscillation frequency in accordance with a total capacitance value of the coupled variable capacitance circuits.

A time integrator integrating time axis information represented by a phase difference between two signals, the time integrator comprising:

• a pulse generation circuit configured to convert a time difference between edges of two input signals to a difference between pulse widths of two pulse signals, and to output the two pulse signals;
• a load circuit having load characteristics changed by the two pulse signals;
• and
• an oscillation circuit coupled to the load circuit, and having an oscillation frequency changing in accordance with the load characteristics of the load circuit,
• wherein an output of the oscillation circuit is output as a result of time integration,
• the pulse generation circuit includes another pulse generation circuit;
• the load circuit includes another load circuit,
• another two signals are input to the another pulse generation circuit,
• each of the load circuits includes a plurality of variable capacitance circuits, each being configured to receive one or the other of the two pulse signals, and having a capacitance value varying in accordance with a logic level of the received pulse signal, and
• each of the oscillation circuits includes an oscillator coupled to the plurality of variable capacitance circuits, and having an oscillation frequency in accordance with a total capacitance value of the coupled variable capacitance circuits.

A ΔΣ time-to-digital converter converting time axis information represented by a phase difference between two signals to a digital value, the ΔΣ time-to-digital converter comprising:

• a time integrator;
• integrating time axis information represented by a phase difference between two signals, the time integrator comprising:
• a pulse generation circuit configured to convert a time difference between edges of two input signals to a difference between pulse widths of two pulse signals, and to output the two pulse signals;
• a load circuit having load characteristics changed by the two pulse signals;
• and
• an oscillation circuit coupled to the load circuit, and having an oscillation frequency changing in accordance with the load characteristics of the load circuit,
• wherein an output of the oscillation circuit is output as a result of time integration,
• the pulse generation circuit includes another pulse generation circuit;
• the load circuit includes another load circuit, and
• another two signals are input to the another pulse generation circuit,
• a time quantizer configured to quantize an output of the time integrator;
• and
• a digital-to-time converter configured to convert a quantized output of the time quantizer to a time difference between edges of two signals, and to output the two signals,
• wherein the two signals output from the digital-to-time converter are input to one of the two pulse generation circuits of the time integrator.