Shaping the drive signal of a mixing device
View Patent ↗Techniques for shaping the drive signal of a mixing device to overcome a characteristic capacitance of the control terminal of the mixing device and reduce the time the mixing device is in an intermediate state between its on and off states.
1. A mixer, comprising:
a mixing device having a control terminal for switching the mixing device in response to a drive signal;
a circuit for shaping the drive signal to overcome a characteristic capacitance of the control terminal when switching the mixing device;
wherein the circuit for shaping includes a bias circuit that generates a bias signal for clamping the drive signal to a switching level for the mixing device; and
wherein the bias circuit supplies a current pulse for shaping the drive signal.
2. The mixer of claim 1 , wherein the circuit for shaping is arranged to track the temperature changes of the mixing device.
3. The mixer of claim 1 , further comprising a switching circuit for switching the bias signal to the control terminal in response to the drive signal.
4. The mixer of claim 3 , wherein the switching circuit switches the bias signal to the control terminal when the drive signal approaches a peak amplitude.
5. A mixer, comprising:
a mixing device;
a drive signal generator for applying a drive signal to a control terminal of the mixing device;
a circuit for shaping the drive signal to overcome a characteristic capacitance of the control terminal;
wherein the circuit for shaping comprises:
a bias circuit for generating a bias signal for clamping the drive signal to a switching level for the mixing device; and
a switching circuit for switching the bias signal to the control terminal in response to the drive signal; and
wherein the bias circuit supplies a current pulse for shaping the drive signal.
6. The mixer of claim 5 , wherein the switching circuit includes a device having a threshold voltage that temperature tracks with a threshold voltage of the mixing device.
7. The mixer of claim 5 , wherein the switching circuit switches the bias signal to the control terminal when the drive signal approaches a peak amplitude.
8. The mixer of claim 5 , wherein the drive signal generator is a square-wave generator.
9. The mixer of claim 5 , wherein the mixing device is a transistor.
10. A method for switching a mixing device in a mixer, said method comprising:
shaping a drive signal applied to the mixing device to overcome a characteristic capacitance of a control terminal of the mixing device; and
wherein the shaping includes generating a current pulse for shaping the drive signal.
11. The method of claim 10 , wherein the shaping includes tracking a temperature change of the mixing device.
12. The method of claim 10 , wherein the shaping includes generating a bias signal for clamping the drive signal to a switching level for the mixing device.
13. The method of claim 12 , wherein the shaping includes switching the bias signal to the control terminal in response to the drive signal.
14. The method of claim 12 , wherein the shaping includes switching the bias signal to the control terminal when the drive signal approaches a peak amplitude.