Apparatus for increasing the switching speed of diodes

Claim 2

A charge pump responsive to first (DN) and second (UP) commands for effecting in a current integrating means (3) a change in voltage proportional to a difference in duration between the first and second commands, comprising a current source (14) for producing a source current; a first switching means (12) responsive to the first command (DN) for passing the source current through the integrating means (3) in a first direction; and a second switching means (13) responsive to the second command (UP) for passing the source current through the integrating means in a second direction opposite to the first direction.

Claim 3

A charge pump according to claim 1, characterised in that the first switching means (12) is connected between the current source (14) and the current integrating means (3) and by a third switching means (11) responsive to the first command (DN) for completing a first current path for the first current from the current integrating means; in that the second switching means (13) is connected between the current source and the current integrating means and by a fourth switching means (10) responsive to the second command (UP) for completing a second current path for the second current from the current integrating means.

Claim 4

A charge pump according to claim 2, characterised in that the first and second switching means (12, 13) pass the source current to a circuit ground when the first and second commands (UP, DN) are simultaneously true.

Claim 5

A charge pump according to claim 2, characterised in that the first and second switching means (12, 13) pass the source current to a circuit ground when the first and second commands (UP, DN) are simultaneously false.

Claim 6

A charge pump according to claim 2, 3 or 4, characterised in that the charge pump is configured as a bridge circuit with the first, second, third, and fourth switching means (12, 13, 11, 10) in respective leg of the bridge circuit; and the current integrating means comprises a capacitor (3) connected across the bridge circuit.

Claim 7

A phase-locked loop comprising a charge pump according to any of claims 1 to 5, a voltage-controlled oscillator (1) responsive to a control voltage for producing a first signal which is periodic at a frequency proportional to the control voltage; means (2) for detecting a phase difference between the first signal and a reference signal, and for producing the first and second commands (UP, DN) a difference between whose durations is proportional to the phase difference; and adjusting means (15) producing the said control voltage from the voltage across the integrating means (3).

Claim 8

Apparatus for increasing the switching speed of a diode having an anode and a cathode, and the diode having a junction voltage which is the amount by which its anode is more positive than its cathode when the diode is in the "ON" condition, and the apparatus comprising: a first circuit responsive to a first signal, the first signal specifying whether the diode is to be switched "ON" or switched "OFF", the first circuit producing at its output a first voltage of plus one-half the junction voltage when the first signal specifies "ON", and minus one-half the junction voltage when the first signal specifies "OFF"; a second circuit having an input connected to the cathode for producing at its output a second voltage greater by one-half the junction voltage than the voltage appearing at the cathode; and a summer circuit connected to the anode for adding the first voltage and the second voltage to produce a sum, and for applying the sum to the anode.

Claim 9

Apparatus for increasing the switching speed of a diode having an anode and a cathode, and the diode having a junction voltage which is the amount by which its anode is more positive than its cathode when the diode is in the "ON" condition, and the apparatus comprising: a first circuit responsive to a first signal, the first signal specifying whether the diode is to be switched "ON" or switched "OFF", the first circuit producing at its output a first voltage of plus one-half the junction voltage when the first signal specifies "ON", and minus one-half the junction voltage when the first signal specifies "OFF"; a second circuit having an input connected to the cathode for producing at its output a second voltage greater by one-half the junction voltage than the voltage appearing at the cathode; and a summer circuit connected to the anode for adding the first voltage and the second voltage to produce a sum, and for applying the sum to the anode.

Claim 10

Apparatus for increasing the switching speeds of a pair of diodes, the pair of diodes consisting of a first diode and a second diode, each having an anode and a cathode, and each diode having a junction voltage being the voltage by which its anode is more positive than its cathode when it is in an ON state, the junction voltage of the first diode being substantially equal to the junction voltage of the second diode; the diode being responsive to first and second voltages, the first voltage having a value of plus one-half the junction voltage when the first diode is to be turned ON and the second diode is to be turned OFF; minus one-half the junction voltage when the first diode is to be turned OFF and the second diode is to be turned ON; or zero volts when both the first and second diodes are to be turned OFF, and the second voltage having a value of plus one-half the junction voltage when the second diode is to be turned ON and the first diode is to be turned OFF; minus one-half the junction voltage when the second diode is to be turned OFF and the first diode is to be turned ON; or zero volts when both the first and second diodes are to be turned OFF, the apparatus comprising a circuit having a first input connected to the cathode of the first diode, the voltage at said cathode being a third voltage; a second input connected to the cathode of the second diode, the voltage at said cathode being a fourth voltage; a first output for producing a fifth voltage which is greater than the third voltage by one-half the junction voltage; and a second output for producing a sixth voltage which is greater than the fourth voltage by one-half the junction voltage; a first summer for adding the first voltage and the fifth voltage to produce a first sum, and for applying the first sum to the anode of the first diode; and a second summer for adding the second voltage and the sixth voltage to produce a second sum, and for applying the second sum to the anode of the second diode.

Claim 11

Apparatus for increasing the switching speeds of a pair of diodes, the pair of diodes consisting of a first diode and a second diode, each having an anode and a cathode, and each diode having a junction voltage being the voltage by which its anode is more positive than its cathode when it is in an ON state, the junction voltage of the first diode being substantially equal to the junction voltage of the second diode; the diode being responsive to first and second voltages, the first voltage having a value of plus one-half the junction voltage when the first diode is to be turned ON and the second diode is to be turned OFF; minus one-half the junction voltage when the first diode is to be turned OFF and the second diode is to be turned ON; or zero volts when both the first and second diodes are to be turned OFF, and the second voltage having a value of plus one-half the junction voltage when the second diode is to be turned ON and the first diode is to be turned OFF; minus one-half the junction voltage when the second diode is to be turned OFF and the first diode is to be turned ON; or zero volts when both the first and second diodes are to be turned OFF, the apparatus comprising a circuit having a first input connected to the cathode of the first diode, the voltage at said cathode being a third voltage; a second input connected to the cathode of the second diode, the voltage at said cathode being a fourth voltage; a first output for producing a fifth voltage which is greater than the third voltage by one-half the junction voltage; and a second output for producing a sixth voltage which is greater than the fourth voltage by one-half the junction voltage; a first summer for adding the first voltage and the fifth voltage to produce a first sum, and for applying the first sum to the anode of the first diode; and a second summer for adding the second voltage and the sixth voltage to produce a second sum, and for applying the second sum to the anode of the second diode.

Claim 12

Apparatus for increasing the switching speeds of a pair of diodes, the pair of diodes consisting of a first diode and a second diode, each having an anode and a cathode, and each diode having a junction voltage being the voltage by which its anode is more positive than its cathode when it is in an ON state, the junction voltage of the first diode being substantially equal to the junction voltage of the second diode; the apparatus being responsive to first and second signals, each being a binary signal having a true state and a false state, so as to switch the first diode ON and the second diode OFF when the first signal is true and the second signal is false; to switch the second diode ON and the first diode OFF when the second signal is true and the first signal is false; to switch both the first and second diodes OFF when the first signal and the second signal are both false; and to switch both the first and second diodes OFF when the first signal and the second signal are both true, the apparatus comprising: a first circuit responsive to the first and second signals for producing a first voltage having a value of plus one-half the junction voltage when the first signal is true and the second signal false; minus one-half the junction voltage when the second signal is true and the first signal false; or zero volts when the first and second signals are both true or both false, a second circuit responsive to the first and second signals for producing a second voltage having a value of plus one-half the junction voltage when the second signal is true and the first signal false; minus one-half the junction voltage when the first signal is true and second signal false; or zero volts when the first and second signals are both true or both false, a third circuit having a first input connected to the cathode of the first diode, the voltage at said cathode being a third voltage; a second input connected to the cathode of the second diode, the voltage at said cathode being a fourth voltage; a first output for producing a fifth voltage which is greater than the third voltage by one-half the junction voltage; and a second output for producing a sixth voltage which is greater than the fourth voltage by one-half the junction voltage; a first summer for adding the first voltage and the fifth voltage to produce a first sum, and for applying the first sum to the anode of the first diode and a second summer for adding the second voltage and the sixth voltage to produce a second sum, and for applying the second sum to the anode of the second diode.

Claim 13

Apparatus for increasing the switching speeds of a pair of diodes, the pair of diodes consisting of a first diode and a second diode, each having an anode and a cathode, and each diode having a junction voltage being the voltage by which its anode is more positive than its cathode when it is in an ON state, the junction voltage of the first diode being substantially equal to the junction voltage of the second diode; the apparatus being responsive to first and second signals, each being a binary signal having a true state and a false state, so as to switch the first diode ON and the second diode OFF when the first signal is true and the second signal is false; to switch the second diode ON and the first diode OFF when the second signal is true and the first signal is false; to switch both the first and second diodes OFF when the first signal and the second signal are both false; and to switch both the first and second diodes OFF when the first signal and the second signal are both true, the apparatus comprising: a first circuit responsive to the first and second signals for producing a first voltage having a value of plus one-half the junction voltage when the first signal is true and the second signal false; minus one-half the junction voltage when the second signal is true and the first signal false; or zero volts when the first and second signals are both true or both false, a second circuit responsive to the first and second signals for producing a second voltage having a value of plus one-half the junction voltage when the second signal is true and the first signal false; minus one-half the junction voltage when the first signal is true and second signal false; or zero volts when the first and second signals are both true or both false, a third circuit having a first input connected to the cathode of the first diode, the voltage at said cathode being a third voltage; a second input connected to the cathode of the second diode, the voltage at said cathode being a fourth voltage; a first output for producing a fifth voltage which is greater than the third voltage by one-half the junction voltage; and a second output for producing a sixth voltage which is greater than the fourth voltage by one-half the junction voltage; a first summer for adding the first voltage and the fifth voltage to produce a first sum, and for applying the first sum to the anode of the first diode and a second summer for adding the second voltage and the sixth voltage to produce a second sum, and for applying the second sum to the anode of the second diode.

Claim 14

The apparatus recited in claim 9, wherein the third circuit establishes a common-mode voltage for the third and fourth voltages, the common-mode voltage being substantially constant and being substantially equal to the average of the third voltage and the fourth voltage.