Neural signal detection circuit outputting time difference data or neural data
There is provided a neural signal detection circuit capable of outputting time difference data or neural data, and including a first temporal circuit and a second temporal circuit. The first temporal circuit is used to store detected voltage energy of a first interval and a second interval as the time difference data. The second temporal circuit is used to store detected voltage energy of the second interval as the neural data. The neural signal detection circuit is used to output the time difference data or the neural data in different operating modes.
1. A neural signal detection circuit, comprising:
an electrode, configured to generate a detected voltage as an electroencephalogram signal;
a first temporal circuit, comprising:
a first capacitor having a first end coupled to the electrode;
a second temporal circuit, comprising:
a second capacitor having a first end coupled to the electrode;
a transfer transistor, connected between the electrode and the first end of the first capacitor as well as the first end of the second capacitor, and configured to transfer the detected voltage to the first temporal circuit in a first interval and a second interval, and transfer the detected voltage to the second temporal circuit in the second interval; and
a reset transistor, connected between the transfer transistor and the first end of the first capacitor as well as the first end of the second capacitor, wherein
a second end of the first capacitor is coupled to an inverting input terminal of a first comparator, which is arranged outside the neural signal detection circuit and shared by the first temporal circuit and other neural signal detection circuits, and
a second end of the second capacitor is coupled to an inverting input terminal of a second comparator, which is arranged outside the neural signal detection circuit and shared by the second temporal circuit and the other neural signal detection circuits, and the second end of the second capacitor is not coupled to the second end of the first capacitor, wherein
the first temporal circuit further comprises a second transistor connected between the first capacitor and the first comparator,
the second temporal circuit further comprises a second transistor connected between the second capacitor and the second comparator, and
the second transistor of the first temporal circuit is not conducted in the second interval, and the second transistor of the second temporal circuit is not conducted in the first interval.
2. The neural signal detection circuit as claimed in claim 1 , wherein the other neural signal detection circuits are multiple neural signal detection circuits at a same column of a detection array as the detection circuit.
3. The neural signal detection circuit as claimed in claim 1 , wherein
the first temporal circuit is configured to record a voltage energy variation from the electrode between the first interval and the second interval, and
the second temporal circuit is configured to record the detected voltage from the electrode in the second interval.
4. The neural signal detection circuit as claimed in claim 3 , wherein a non-inverting input terminal of the first comparator is configured to
receive a ramp signal to cause the first comparator to output a pulse width signal corresponding to the voltage energy variation, or
sequentially receive an upper threshold voltage and a lower threshold voltage to confirm whether the voltage energy variation exceeds the upper threshold voltage or the lower threshold voltage.
5. The neural signal detection circuit as claimed in claim 3 , wherein a non-inverting input terminal of the second comparator is configured to
receive a ramp signal to cause the second comparator to output a pulse width signal corresponding to the detected voltage.
6. The neural signal detection circuit as claimed in claim 1 , further comprising:
a first source follower, connected to the first capacitor and the second transistor of the first temporal circuit;
a first row selection transistor, connected between the first source follower and the first comparator;
a second source follower, connected to the second capacitor and the second transistor of the second temporal circuit; and
a second row selection transistor, connected between the second source follower and the second comparator.
7. A neural signal detection circuit, comprising:
a source follower;
a first temporal circuit, comprising:
a first capacitor having a first end coupled to the source follower;
a second temporal circuit, comprising:
a second capacitor having a first end coupled to the source follower, wherein
a second end of the first capacitor is coupled to an inverting input terminal of a first comparator, which is arranged outside the neural signal detection circuit and shared by the first temporal circuit and other neural signal detection circuits, and
a second end of the second capacitor is coupled to an inverting input terminal of a second comparator, which is arranged outside the neural signal detection circuit and shared by the second temporal circuit and the other neural signal detection circuits, and the second end of the second capacitor is not coupled to the second end of the first capacitor;
a first source follower, connected to the second end of the first capacitor;
a first row selection transistor, connected between the first source follower and the first comparator;
a second source follower, connected to the second end of the second capacitor; and
a second row selection transistor, connected between the second source follower and the second comparator.
8. The neural signal detection circuit as claimed in claim 7 , further comprising:
an electrode, configured to generate detected voltage as an electroencephalogram signal;
a transfer transistor, connected between the electrode and the source follower, and configured to transfer the detected voltage to the first temporal circuit via the source follower in a first interval and a second interval, and transfer the detected voltage to the second temporal circuit via the source follower in the second interval; and
a reset transistor, connected between the transfer transistor and the source follower.
9. The neural signal detection circuit as claimed in claim 8 , wherein
the first temporal circuit is configured to record a voltage energy variation from the electrode between the first interval and the second interval, and
the second temporal circuit is configured to record the detected voltage from the electrode in the second interval.