Delay device and control method of transmission delay
A delay device and a control method of transmission delay capable of performing temperature compensation are provided. The delay device includes a first current source, a second current source, a first resistor, and a delay adjustment circuit. The first current source is configured to provide a first current with a constant temperature coefficient. The second current source is connected to the first current source in parallel and is configured to provide a second current with a negative temperature coefficient. A first terminal of the first resistor is coupled to the first current source and the second current source. A second terminal of the first resistor is coupled to a reference ground terminal. The first resistor generates a control voltage at the first terminal of the first resistor according to the first current and the second current. The delay adjustment circuit is coupled to a transmission wire. The delay adjustment circuit determines a signal transmission delay of the transmission wire according to the control voltage.
1. A delay device, comprising:
a first current source, providing a first current with a constant temperature coefficient;
a second current source, connected to the first current source in parallel and providing a second current with a negative temperature coefficient;
a first resistor, wherein a first terminal of the first resistor is coupled to the first current source and the second current source, a second terminal of the first resistor is coupled to a reference ground terminal, and the first resistor generates a control voltage on the first terminal of the first resistor according to the first current and the second current; and
a delay adjustment circuit, coupled to a transmission wire and determining a signal transmission delay of the transmission wire according to the control voltage.
2. The delay device according to claim 1 , wherein the first current source is a variable current source, and a current value of the first current is adjusted by a current control signal applied to the first current source.
3. The delay device according to claim 1 , wherein the second current source is a variable current source, and a current value of the second current is adjusted by a current control signal applied to the second current source.
4. The delay device according to claim 1 , further comprising:
a second resistor, coupled in series between the first current source and the first terminal of the first resistor.
5. The delay device according to claim 1 , wherein the first resistor is a variable resistor.
6. The delay device according to claim 1 , wherein the delay adjustment circuit comprises a plurality of current-controlled delayers, and the current-controlled delayers adjust the signal transmission delay according to the control voltage.
7. The delay device according to claim 6 , wherein each of the current-controlled delayers comprises:
a first transistor, wherein a first terminal of the first transistor is coupled to the transmission wire, a control terminal of the first transistor receives the control voltage, and the first transistor generates a third current according to the control voltage; and
a second transistor, coupled between a second terminal of the first transistor and the reference ground terminal, wherein the second transistor is coupled as a diode.
8. The delay device according to claim 7 , wherein a change of the control voltage is positively related to changes in turn-on voltages of the first transistor and the second transistor according to the ambient temperature.
9. The delay device according to claim 7 , wherein each of the current-controlled delayers charges or discharges the second transistor according to the third current to generate a delay.
10. A control method of transmission delay, comprising:
providing a first current with a constant temperature coefficient;
providing a second current with a negative temperature coefficient;
allowing the first current and the second current to flow through a resistor and generating a control voltage on a terminal of the resistor receiving the first current and the second current; and
determining a signal transmission delay of a transmission wire according to the control voltage.
11. The control method according to claim 10 , further comprising:
adjusting a current value of the first current according to a corresponding current control signal.
12. The control method according to claim 10 , further comprising:
adjusting a current value of the second current according to a corresponding current control signal.
13. The control method according to claim 10 , wherein the step of determining the signal transmission delay of the transmission wire according to the control voltage further comprises:
providing a first transistor, wherein the first transistor is coupled to the transmission wire;
allowing the first transistor to generate a third current according to the control voltage; and
charging or discharging the second transistor according to the third current to generate a delay.
14. The control method according to claim 13 , wherein a change of the control voltage is positively related to changes in turn-on voltages of the first transistor and the second transistor according to the ambient temperature.