Booster circuit
View Patent ↗An oscillation circuit 10 outputs oscillation clocks 100 different in phase, and a four-phase clock generation circuit 20 generates a four-phase clock 200 based on a difference in phase between the oscillation clocks 100 . A four-phase clock transfer control circuit 50 controls whether to transfer the four-phase clock 200 in accordance with a signal CP_EN, and a pump circuit 60 generates a boosted voltage based on the transferred four-phase clock. A time period of delay Tos between clocks included in the four-phase clock 200 is generated based on the difference in phase between the oscillation clocks 100 , and therefore always in a proportional relationship with a cycle (Tosc) of the oscillation clocks 100 . Accordingly, even if the cycle (Tosc) is changed due to operating conditions, and therefore a time period of charge transfer (Ttr) can be uniquely determined.
1. A booster circuit operating based on a multiphase clock, comprising:
an oscillation circuit for outputting sets of a plurality of oscillation clocks different in phase from each other and providing a set of plurality of source oscillation clocks different in phase from each other for each of multiphase clock generation circuits;
said each of multiphase clock generation circuits for generating the multiphase clock based on the set of a plurality of source oscillation clocks different in phase from each other;
a pump circuit for generating a boosted voltage based on the multiphase clock;
a multiphase clock transfer control circuit for controlling whether to transfer the multiphase clock from the multiphase clock generation circuit to the pump circuit in accordance with a control signal; and
a detection circuit for comparing the boosted voltage generated in the pump circuit with a predetermined target voltage, and outputting the control signal to said multiphase clock transfer control circuit,
wherein when the multiphase clock transfer control circuit ceases to transfer the multiphase clock, the multiphase clock is held at a value taken at a time of ceasing transfer of the multiphase clock, and the multiphase clock transfer control circuit restarts transferring the multiphase clock when the multiphase clock generated by the multiphase clock generation circuit takes the value taken at a time of ceasing to be transferred.
2. The booster circuit according to claim 1 , wherein the multiphase clock transfer control circuit includes:
a plurality of control signal storage circuits for storing, for each cycle of the multiphase clock, values of the control signal at different times;
a timing storage circuit for storing a time at which any value stored in the control signal storage circuit has been changed from the first value to the second value; and
a clock mask circuit for passing the multiphase clock when the values stored in the control signal storage circuit are all equal to the first value, and holding the multiphase clock at a predetermined value in accordance with the time stored in the timing storage circuit when otherwise.
3. A booster circuit operating based on a multiphase clock, comprising:
an oscillation circuit for outputting sets of a plurality of oscillation clocks different in phase from each other and providing a set of a plurality of source oscillation clocks different in phase from each other for each of multiphase clock generation circuits;
said each of multiphase clock generation circuits for generating the multiphase clock based on the set of a plurality of source oscillation clocks different in phase from each other; and
a plurality of pump circuits for generating a plurality of boosted voltages different in level from each other based on the multiphase clock;
a multiphase clock transfer control circuit for controlling whether to transfer the multiphase clock from the multiphase clock generation circuit to the pump circuit in accordance with a control signal; and
a detection circuit for comparing the boosted voltage generated in the pump circuit with a predetermined target voltage, and outputting the control signal to said multiphase clock transfer control circuit,
wherein when the multiphase clock transfer control circuit ceases to transfer the multiphase clock, the multiphase clock is held at a value taken at a time of ceasing transfer of the multiphase clock, and the multiphase clock transfer control circuit restarts transferring the multiphase clock when the multiphase clock generated by the multiphase clock generation circuit takes the value taken at a time of ceasing to be transferred.
4. The booster circuit according to claim 3 , further comprising a multiphase clock delay circuit for delaying the multiphase clock, wherein the plurality of pump circuits are supplied with multiphase clocks which are caused to be delayed by different time periods by the multiphase clock delay circuit.
5. The booster circuit according to claim 3 , further comprising a boost-assist circuit for causing a current to flow between output terminals of the plurality of pump circuits only in a predetermined direction.
6. A booster circuit operating based on a multiphase clock, comprising
an oscillation circuit for outputting a plurality of oscillation clocks different in phase from each other;
a multiphase clock generation circuit for generating the multiphase clock based on the plurality of oscillation clocks; and
a pump circuit for generating a boosted voltage based on the multiphase clock,
wherein the pump circuit includes a plurality of stages of booster cells connected in series with each other,
wherein the plurality of booster cells each include:
a charge transfer transistor for transferring an output voltage from a circuit in the booster cell in a previous stage to a circuit in the booster cell in a next stage;
an output voltage boosting capacitor having a first electrode connected to an output terminal of the charge transfer transistor and a second electrode to which a first clock contained in the multiphase clock is supplied;
a gate voltage boosting capacitor having a first electrode connected to a gate terminal of the charge transfer transistor and a second electrode to which a second clock contained in the multiphase clock;
a switch transistor for performing switching to couple an input terminal of the charge transfer transistor to a gate terminal thereof; and
a voltage reset circuit for resetting a gate voltage of the charge transfer transistor to a predetermined voltage level in accordance with a given reset control signal, and
wherein in a booster cell in a first stage, an inverted signal of the reset control signal is applied to a well of the charge transfer transistor and a well of the switch transistor, and in a booster cell in any stage other than the first stage, the output voltage of the circuit in the previous stage is applied to a well of the charge transfer transistor and a well of the switch transistor.
7. A booster circuit operating based on a multiphase clock, comprising:
an oscillation circuit for outputting sets of a plurality of oscillation clocks different in phase from each other and providing a set of plurality of source oscillation clocks different in phase from each other for each of multiphase clock generating circuits;
said each of multiphase clock generation circuits for generating the multiphase clock based on the set of a plurality of source oscillation clocks different in phase from each other; and
a pump circuit for generation a boosted voltage based on the multiphase clock;
a multiphase clock transfer control circuit for controlling whether to transfer the multiphase clock from the multiphase clock generation circuit to the pump circuit in accordance with a control signal; and
a detection circuit for comparing the boosted voltage generated in the pump circuit with a predetermined target voltage, and outputting the control signal to said multiphase clock transfer control circuit.