Source: http://www.google.com/patents/US8076915?dq=3691140
Timestamp: 2017-12-17 04:47:32
Document Index: 748945667

Matched Legal Cases: ['art 31', 'art 31', 'art 31', 'art 31', 'art 31', 'Application No. 200610064895', 'Application No. 06251408', 'Application No. 2006', 'Application No. 10']

Patent US8076915 - Switching converter - Google Patents
To improve conversion efficiency at a DC-DC conversion time by providing driving units respectively for a plurality of switches and controlling the switches corresponding to a load current, an input voltage, an output voltage and an input/output voltage difference. When synchronously rectifying a plurality...http://www.google.com/patents/US8076915?utm_source=gb-gplus-sharePatent US8076915 - Switching converter
Publication number US8076915 B2
Application number US 12/357,267
Also published as EP1703626A2, EP1703626A3, EP1703626B1, EP2254225A1, EP2254225B1, US7492135, US20060208715, US20090230939
Publication number 12357267, 357267, US 8076915 B2, US 8076915B2, US-B2-8076915, US8076915 B2, US8076915B2
Inventors Shigeaki Nakazawa
Patent Citations (23), Non-Patent Citations (8), Referenced by (6), Classifications (7), Legal Events (2)
US 8076915 B2
To improve conversion efficiency at a DC-DC conversion time by providing driving units respectively for a plurality of switches and controlling the switches corresponding to a load current, an input voltage, an output voltage and an input/output voltage difference. When synchronously rectifying a plurality of first switches and a plurality of second switches by setting the first switches and the second switches alternately in an ON-state, the plurality of first switches are driven repeatedly in the ON- or OFF-state corresponding to a required output, the plurality of second switches are driven in the ON- or OFF-state in synchronization with the first switches, the driving of part of the plurality of first switches and part or all of the plurality of second switches is stopped corresponding to a load current value, an input voltage value, an output voltage value or an input/output voltage difference value.
wherein the A-driving unit is set to have a larger capacity than the B-driving unit, and the selection unit drives the A-driving unit when the output load is higher than a predetermined value and drives the B-driving unit when the output load is equal to or lower than the predetermined value.
2. A switching converter according to claim 1, wherein the first A-switch and the second A-switch is set to have a larger capacity than the first B-switch and the second B-switch have, and
3. A switching converter according to claim 1, wherein the A-coil may be set to have a larger capacity than the B-coil, and
4. A switching converter according to claim 3, wherein the A-coil has a lower inductance than the B-coil.
5. A switching converter according to claim 1, wherein the A-coil extends from one terminal of the single coil up to a middle point thereof, and the B-coil extends from the middle point up to the other terminal thereof.
6. A switching converter according to claim 1, wherein the selection unit receives information representing an operating state of a load-sided circuit, and drives the A-driving unit or the B-driving unit in accordance with the information.
7. A switching converter according to claim 1, wherein the selection unit drives the A-driving unit or the B-driving unit in accordance with an output current.
8. An electronic device having a switching converter and a load operating by an output from the switching converter, the switching converter including:
This application is a Continuation of U.S. Ser. No. 11/377,213, filed Mar. 17, 2006 now U.S. Pat. No. 7,492,135, currently pending, which is a Continuation-In-Part Application of U.S. Ser. No. 11/239,364, filed Sep. 30, 2005 now abandoned, and incorporated herein by reference.
The invention relates to a technology for conducting synchronous rectification type DC-to-DC conversion or AC-to-DC conversion.
[Patent document 2] Japanese Patent Application Laid-Open Publication No. 2003-319649.
As described above, in the DC-DC converter provided with the driver for every phase, if the drivers are stopped, all of the plurality of FETs driven by the drivers can not be used, and hence only the control as simple as stopping the respective phases or stopping the respective phases, wherein optimum conversion efficiency is not necessarily acquired depending on the load and a state of input/output voltages.
A general type of power source circuit is designed in consideration of a maximum load status and has such a tendency that a converting efficiency abruptly declines in the low-load status. Therefore, it is also considered that in the low-load status, the efficiency is increased by decreasing an oscillation frequency in a way that changes the oscillation system from a PWM (Pulse Width Modulation) system to a PFM (Pulse Frequency Modulation) system. However, a loss per oscillation is the same, and this loss is required to be reduced.
Further, a control circuit of the invention is a control circuit of a switching converter for converting an input electric power to an output electric power by setting a first switch and a plurality of second switches alternately to an ON-state, the control circuit including: a first driving unit for driving the first switch; a plurality of second driving units for respectively driving the plurality of second switches; and a selection unit for stopping part or the whole of the plurality of second driving units in accordance with a load current value, an input voltage value, an output voltage value or an input/output voltage difference value.
Further, a switching converter of the invention includes: a plurality of first switches; a second switch; a plurality of first driving units for driving each of the plurality of first switches; a second driving unit for driving the second switch; a detection unit for detecting a load current value, an input voltage value, an output voltage value or an input/output voltage difference value; and a selection unit for stopping part of the plurality of first driving units in accordance with a result of the detection by the detection unit.
Still further, a switching converter of the invention includes: a first switch; a plurality of second switches; a first driving unit for driving the first switch; a plurality of second driving units for driving each of the plurality of second switches; a detection unit for detecting a load current value, an input voltage value, an output voltage value or an input/output voltage difference value; and a selection unit for stopping part or all of the plurality of second driving units in accordance with a result of the detection by the detection unit.
Moreover, a switching converter of the invention includes: a plurality of first switches; a plurality of second switches; a plurality of first driving units for repeatedly driving the plurality of first switches in an ON- or OFF-state in accordance with a required output; a plurality of second driving units for driving respectively the plurality of second switches in the ON-state in synchronization with the first switches; a detection unit for detecting pieces of predetermined information (a load current value, an output voltage value, an input voltage value or an input/output voltage difference value); and a selection unit for stopping part of the plurality of first driving units and part or all of the plurality of second driving units in accordance with the information detected by the detection unit.
The first switch may be an FET, wherein a drain terminal is connected to an input terminal, a source terminal is connected to the second switch, and a gate terminal is connected to the first driving unit. A plurality of FETs may be connected in parallel between the input terminal and the second switch.
In the switching converter, the first A-switch and the second A-switch may be set to have a larger capacity than the first B-switch and the second B-switch have, and the selection unit may drive the A-driving unit when an output load is higher than a predetermined value and may drive the B-driving unit when the output load is equal to or lower than the predetermined value.
In the switching converter, the A-coil may be set to have a larger capacity than the B-coil, and the selection unit may drive, corresponding to a load on the output side, the A-driving unit when the load is higher than a predetermined value and may drive the B-driving unit when the load is equal to or lower than the predetermined value.
The A-coil may have a lower inductance than the B-coil.
In the switching converter, the A-driving unit may be set to have a larger capacity than the B-driving unit, and the selection unit may drive, corresponding to a load on the output side, the A-driving unit when the load is higher than a predetermined value and may drive the B-driving unit when the load is equal to or lower than the predetermined value.
In the switching converter, the A-coil may extend from one terminal of the single coil up to a middle point thereof, and the B-coil may extend from the middle point up to the other terminal thereof.
In the switching converter, the selection unit may receive information representing an operating state of a load-sided circuit, and may drive the A-driving unit or the B-driving unit in accordance with the information.
The selection unit may drive the A-driving unit or the B-driving unit in accordance with an output current.
Further, a switching converter of the invention includes: a first A-FET having a drain terminal that is connected to an input terminal; a second A-FET having a drain terminal that is connected to a source terminal of the first A-FET, and a source terminal that is connected to the ground; an A-driving unit connected to gate terminals of the first A-FET and of the second A-FET, and driving the first A-FET and the second A-FET alternately; an A-coil having one terminal that is connected to an A-oscillation part to which the source terminal of the first A-FET and the drain terminal of the second A-FET are connected, and having the other terminal that is connected to an output terminal; a first B-FET having a drain terminal that is connected to an input terminal; a second B-FET having a drain terminal that is connected to the source terminal of the first B-FET and a source terminal that is connected to the ground; a B-driving unit connected to gate terminals of the first B-FET and of the second B-FET, and driving the first B-FET and the second B-FET alternately; a B-coil having one terminal that is connected to an B-oscillation part to which the source terminal of the first B-FET and the drain terminal of the second B-FET are connected, and having the other terminal that is connected to A-oscillation part; and a selection unit for selectively driving the A-driving unit and the B-driving unit.
Moreover, an electronic device of the invention is a device having a switching converter and a load operating by an output from the switching converter, the switching converter including: an A-coil connected to the output terminal; a first A-switch for switching electric power outputted via the A-coil; a second A-switch for making rectification so as to become an ON-state alternately with the first A-switch; an A-driving unit for driving the first A-switch and the second B-switch alternately; a B-coil connected in series to the A-coil; a first B-switch for switching the electric power outputted via the B-coil and the A-coil; a second B-switch for making the rectification so as to become an ON-state alternately with the first B-switch; an A-driving unit for driving the first B-switch and the second B-switch alternately; and a selection unit for causing the A-driving unit and the B-driving unit to drive selectively.
According to the invention, it is possible to improve the conversion efficiency at the switching conversion time by providing the driving units respectively for the plurality of switches and controlling the respective switches in accordance with the load current value, the input voltage value, the output voltage value and the input/output voltage difference value.
FIG. 1 is a diagram of an outline of a first embodiment of the invention.
A best mode for carrying out the invention will hereinafter be described with reference to the drawings. Configurations of the following embodiments are exemplifications, and the invention is not limited to the configurations of the embodiments.
FIG. 1 is a diagram of an outline of a synchronous rectification type switching converter (DC-DC converter) according to the invention.
FETs (Field-Effect Transistors) 11 a, 11 b defined as first switches are provided in parallel between an input terminal 10 a and an output terminal 10 b of this DC-DC converter 1, and an inductor L is disposed on the side of the output terminal 10 b. Further, FETs 12 a, 12 b as second switches are provided in parallel between this inductor L and an earthed point 13. Herein, the first and second switches involve using the FETs and may also be other types of switching elements without being limited to the FETs.
Moreover, a diode 14 a is disposed in parallel with the synchronous rectification FETs 12 a, 12 b.
Then, this DC-DC converter 1 is provided with a control circuit 15 for controlling the output control FETs 11 a, 11 b and the synchronous rectification FETs 12 a, 12 b so as to set these FETs in an ON-state, alternately.
FIG. 2 is a diagram showing ON/OFF time changes of the output control FETs 11 a, 11 b and the synchronous rectification FETs 12 a, 12 b.
Thus, an electric current from the input terminal 10 a is kept flowing during only a period of the ON-state of the output control FETs 11 a, 11 b, then smoothed by the inductor L and a capacitor C and thus outputted, whereby an input voltage is converted into an output voltage corresponding to a duty ratio of the output control FETs 11 a, 11 b.
The control circuit 15 includes drivers 16 a-16 d for respectively driving the output control FETs 11 a, 11 b and the synchronous rectification FETs 12 a, 12 b, a selector 17 for selectively stopping the drivers 16 a-16 d, and a PWM comparator 18 for supplying pulse signals to the respective drivers 16 a-16 d via the selector 17.
As shown in FIG. 3, if there is a large I/O voltage difference (15 V), the ON-time of the output control FETs 11 a, 11 b is as short as 0.625 μs, and a product of the electric power applied to the output control FETs 11 a, 11 b is small. Further, as shown in FIG. 4, if the I/O voltage difference is small (1 V), the ON-time of the output control FETs 11 a, 11 b is as long as 9.375 μs, and the product of the electric power applied to the output control FETs 11 a, 11 b is large. Therefore, if the DC-DC converter is a converter capable of converting the output voltage into 1 V trough 15 V when the input voltage is 16 V, the output control FETs 11 a, 11 b are so designed as to withstand the minimum I/O voltage difference (1 V). Hence, as shown in FIG. 3, if the I/O voltage difference increases and falls within an allowable range of one output control FET, switching can be done by only the other even when stopping one of the output control FETs 11 a, 11 b.
For example, when stopping the output control FET 11 a, a drain current of the output FET 11 b comes to 10 A, and, if the output control FET 11 b withstands the drain current of 10 A for 2 μs, it can be said that the output control FET 11 b is capable of switching with the I/O voltage difference that is on the order of 10 V. Such being the case, the selector 17 is set so as to stop the driver 16 a for the output control FET 11 a if the I/O voltage difference is equal to or larger than 10 V and to drive the drivers 16 a, 16 b for both of the output control FETs 11 a and 11 b if the I/O voltage difference is less than 10 V. Note that these numerical values can be arbitrarily set depending on the FETs to be used, a load, and so on. Further, the example has exemplified the case of stopping one of the two output control FETs 11 a, 11 b, and may also adopt such a configuration that a larger number of output control FETs are provided, part of these FETs are stopped, and the remaining FETs conduct switching.
On the other hand, as shown in FIG. 3, if the I/O voltage difference is large (15 V), the ON-time of the synchronous rectification FETs 12 a, 12 b is as long as 9.375 μs, and a product of electric power applied to the synchronous rectification FETs 12 a, 12 b is large. Further, as shown in FIG. 4, if the I/O voltage difference is small (1 V), the ON-time of the synchronous rectification FETs 12 a, 12 b is as short as 0.625 μs, and the product of the electric power applied to the synchronous rectification FETs 12 a, 12 b is small. Accordingly, if the DC-DC converter is the converter capable of converting the output voltage into 1 V trough 15 V when the input voltage is 16 V, the synchronous rectification FETs 12 a, 12 b are so designed as to withstand the maximum I/O voltage difference (15 V). Hence, as shown in FIG. 4, if the I/O voltage difference decreases and falls within an allowable range of one synchronous rectification FET, switching can be done by only the other even when stopping one of the synchronous rectification FETs 12 a, 12 b.
Moreover, if the electric power applied to the synchronous rectification FETs 12 a, 12 b is small and if a power loss is small enough to be ignorable when this electric power is applied to the diode 14, all the synchronous rectification FETs 12 a, 12 b may be stopped.
For example, when stopping the synchronous rectification FET 12 a, the drain current of the synchronous rectification FET 12 b comes to 10 A, and the synchronous rectification FET 12 b, if able to withstand the drain current of 10 A for 2 μs, can be said to be capable of switching with the I/I voltage difference of 3 V. Such being the case, the selector 17 is set so as to stop the drivers 16 a, 16 d for both of the synchronous rectification FETs 12 a, 12 b if the I/O voltage difference is less than 1.5 V, to stop the driver 16 c for the synchronous rectification FET 12 a if the I/O voltage difference is equal to or larger than 1.5 V but is equal to or smaller than 3 V, and to drive the drivers 16 c, 16 d for both of the synchronous rectification FETs 12 a, 12 b if the I/O voltage difference exceeds 3 V. Note that these numerical values can be arbitrarily set depending on the FETs to be used, a load, and so on. Further, the example has exemplified the case of stopping one or two of the two synchronous rectification FETs 12 a, 12 b, and may also adopt such a configuration that a larger number of synchronous rectification FETs are provided, part of these FETs are stopped, and the remaining FETs conduct switching.
For example, there are provided four pieces of driver circuits having power consumption of 25 mW per piece (namely, the power consumption of all the driver circuits is given by 25 mW×4=100 mW), and, when operating these four driver circuits, there must be a 20% loss with respect to a load of load power given by 5 V×100 mA=500 mW. Herein, in the case of driving only two driver circuits while stopping part of these driver circuits, an improvement of a 50 mW power loss can be attained. That is, the power loss can be reduced down to 10% from 20% with respect to the load.
FIG. 5 is a diagram of an outline of a DC-DC converter shown by way of a second embodiment. The second embodiment is different from the first embodiment in terms of a point that the driver to be stopped is determined corresponding to a load current, and other configurations are the same. Therefore, the same components as those in the first embodiment are marked with the same numerals and symbols, and the repetitive explanations are omitted in principle.
As shown in FIG. 5, a DC-DC converter 1 a in the second embodiment includes a load current detector 24 that detects a current flowing across a resistor R in the vicinity of an output terminal 10 b, i.e., detects the output current (load current), wherein a signal corresponding to this output current is inputted to a selector 17 a.
Then, the selector 17 a in the second embodiment stops the driver on the basis of this load current and the I/O voltage difference described above.
Then, if the load current is 12 A with respect to the drivers 16 c, 16 d on the synchronous rectification side, the selector 17 is set to stop the drivers 16 c, 16 d for both of the synchronous rectification FETs 12 a, 12 b when the I/O voltage difference is less than 1.1 V, to stop the driver 16 c for the synchronous rectification FET 12 a when the I/O voltage difference is equal to larger than 1.1 V but is equal to or smaller than 2 V, and to drive the drivers 16 c, 16 d for both of synchronous rectification FETs 12 a, 12 b when the I/O voltage difference exceeds 2 V, and is further set to, if the load current is 10 A, stop the drivers 16 c, 16 d for both of the synchronous rectification FETs 12 a, 12 b when the I/O voltage difference is less than 1.5 V, to stop the driver 16 c for the synchronous rectification FET 12 a when the I/O voltage difference is equal to larger than 1.5 V but is equal to or smaller than 3 V, and to drive the drivers 16 c, 16 d for both of synchronous rectification FETs 12 a, 12 b when the I/O voltage difference exceeds 3 V. Note that these numerical values can be arbitrarily set depending on the FETs to be used, a load, and so on. Further, the example has exemplified the case of stopping one of the two output control FETs 11 a, 11 b, and the case of stopping one or two of the two synchronous rectification FETs 12 a, 12 b, and may also adopt such a configuration that a larger number of FETs are provided, part of these FETs are stopped, and the remaining FETs conduct switching.
FIG. 6 is a diagram showing an outline of the switching converter (DC-DC converter) by way of a third embodiment of the invention.
Namely, the DC-DC converter 1 b includes an FET 11 a (corresponding to a first A-FET) of which a drain terminal is connected to the input terminal 10 a, an FET 12 a (corresponding to a second A-FET) of which a drain terminal is connected to a source terminal of the FET 11 a and of which a source terminal is connected to the ground, a coil L1 (corresponding to an A-coil) having one terminal that is connected to an oscillation part 31 a (corresponding to an A-oscillation part) to which the source terminal of the FET 11 a and the drain terminal of the FET 12 a are connected, and having the other terminal that is connected to the output terminal 10 b, an FET 11 b (corresponding to a first B-FET) of which a drain terminal is connected to the input terminal 10 a, an FET 12 b (corresponding to a second B-FET) of which a drain terminal is connected to the source terminal of the FET 11 b and of which a source terminal is connected to the ground, and a coil L2 (corresponding to a B-coil) having one terminal that is connected to an oscillation part 31 b (corresponding to a B-oscillation part)) to which the source terminal of the FET 11 b and the drain terminal of the FET 12 b are connected, and having the other terminal that is connected to the oscillation part 31 a.
Herein, the first and second switches involve using the FETs, however, other switching elements may also be usable without being limited to the FETs.
Diodes 14 are disposed in parallel with the synchronous rectification FETs 12 a, 12 b.
Then, a control circuit 15 drives the FET 11 a and the FET 12 a so that these FETs become an ON-state alternately or drives the FET 11 b and the FET 12 b so that these FETs become an ON-state alternately.
Thus, the output control FETs 11 a, 11 b output a voltage applied to the input terminal 10 a during the ON-state set by the control circuit 15, and the voltage is smoothed by the inductors L1, L2 and by a capacitor C1. Namely, the DC-DC converter 1 b converts the input voltage into an output voltage corresponding to a duty ratio of the output control FETs 11 a, 11 b.
The control circuit 15 includes an FET driver (corresponding to an A-driving unit) 26 a connected between the gate and the source of the output control FET 11 a and the synchronous rectification FET 12 a and driving the FET 11 a and the FET 12 a so that these FETs become the ON-state alternately, an FET driver (corresponding to a B-driving unit) 26 b connected between the gate and the source of the output control FET 11 b and the synchronous rectification FET 12 b and driving the FET 11 b and the FET 12 b so that these FETs become the ON-state alternately, detection units 23, 24 for detecting the outputs, an oscillation control unit (corresponding to a selection unit) 17 for controlling the FET drivers 26 a, 26 b in accordance with the outputs etc, and a clock generation unit 21 for generating a clock.
The output current detection unit 24 serves to detect the output current of the converter 1 b and is constructed of, for instance, a differential amplifier etc that inputs, to the oscillation control unit 17, a signal (output current signal) corresponding to a voltage difference between both of the terminals of a low-resistance R provided on the side of the output terminal 10 b.
The oscillation control unit 17 generates a pulse signal having a width corresponding to the output deviation signal from the output voltage detection unit 23 at a timing of the clock inputted from the clock generation unit 21, selectively inputs the pulse signal to the FET drivers 26 a, 26 b, and sets ON/OFF the output control FETs 11 a, 11 b as shown in FIG. 2. Herein, the oscillation control unit 17 outputs the pulse signal to the FET driver 26 a when the output current signal is equal to or larger than a predetermined value, and outputs the pulse signal to the FET driver 26 b when the output current signal is less than the predetermined value. For example, the oscillation control unit 17 has a logic circuit outputting Lo when the output current signal is less than the predetermined value and outputting Hi when the output current signal is equal to or higher than the predetermined value, and a selector that outputs the pulse signal to the FET driver 26 a when the output of the logic circuit is Hi and outputs the pulse signal to the FET driver 26 b when the output of the logic circuit is Lo. Note that the predetermined value is not limited to one value and may take a plurality of values. For example, there may be employed the logic circuit that changes the output to Lo when the output current signal is less than a first threshold value and changes the output to Hi when the output current signal is equal to or larger than a second threshold value (where the first threshold value<the second threshold value), and keeps the present state when between the first threshold value and the second threshold value.
Still further, the FET 11 b and the FET 12 b have a smaller capacitance than the FET 11 a and the FET 12 a have, and hence the efficiency and an packaging area can be optimized by setting the capacitance of the FET driver 26 b smaller than the FET driver 26 a.
As discussed above, the DC-DC converter in the third embodiment selectively drives any one group of the large-capacitance switches (11 a, 12 a) and the small-capacitance switches (11 b, 12 b) in accordance with the load state, and therefore the power source circuit having the high efficiency and the high responsiveness can be actualized even in any state of the low-load state and the high-load state.
For instance, when the input voltage is 16V, the output voltage is 3.3V and the load current is 10 mA, in the circuit in FIG. 13, the inductance of the coil L3 can not be set large if the high-load time is taken into consideration, so that L3=2.5 pH, and, when setting ON-time per operation to 1 μsec, the oscillation frequency comes to 832 Hz. FIG. 7 shows an output voltage and an oscillation waveform in this state.
FIG. 9 is a circuit diagram in a modified example 1 of the third embodiment. This modified example is different in terms of using a single coil L12 in place of the coils L1, L2. Note that other configurations are the same.
As shown in FIG. 9, in this modified example, one terminal of the coil L12 is connected to an oscillation part 31 b of the coil L12, the other terminal is connected to the output terminal 10 b, and a middle point is connected to an oscillation part 31 a.
Namely, the coil L12 in this modified example includes the coil L1 extending from an output-side terminal portion up to the middle point and the coil L2 extending from the middle point up to the output-side terminal portion.
FIG. 10 is a circuit diagram in a modified example 2 of the third embodiment. The third embodiment has exemplified the example of including the two tuples of output control switches and of the synchronous rectification switches, however, the configuration is not limited to this example, and the output control switches and the synchronous rectification switches may also be provided.
FIG. 11 is a perspective view of an external configuration of a notebook type personal computer (which corresponds to an electronic device and will hereinafter be also called a notebook PC) as an electronic device of the invention. FIG. 12 is an explanatory diagram showing a periphery to a power source unit of the notebook PC. The third embodiment exemplifies an example of a notebook PC 10 including the power source unit provided with the same DC-DC converter 1 as the first embodiment has. Note that the same components as those in the first embodiment are marked with the same numerals and symbols, and the repetitive explanations are omitted.
The AC adapter 20 has a function of converting the electric power of a commercial power source 40 into the DC power of, e.g., 16 V, and supplying the DC power to the power source unit 60 of the notebook PC 10. The power supplied to this power source unit 60 is transferred to an input terminal 10 a of the DC-DC converter via a diode D3, and the DC-DC converter 1 converts this power into power having a voltage employed in circuits (load) of the respective units within the notebook PC 10. Note that FIG. 12 illustrates only one output terminal 10 b from the DC-DC converter 1, however, the output terminal is not limited to one. For instance, a configuration is that the output terminals may be provided for a plurality of lines, and voltages different from each other may be outputted there from.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switches and the second switch alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; and a selection unit stopping part of the plurality of first driving units in accordance with a load current.
A control circuit of a switching converter converting an input electric power to an output electric power by setting the first switch and a plurality of second switches alternately to an ON-state, comprising: a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part or all of the plurality of second driving units in accordance with a load current.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switches and a plurality of second switches alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; and a selection unit stopping part of the plurality of first driving units in accordance with an input voltage.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a first switch and a plurality of second switches alternately to an ON-state, comprising: a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part or all of the plurality of second driving units in accordance with an input voltage.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switches and a second switch alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; and a selection unit stopping part of the plurality of first driving units in accordance with an output voltage.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a first switch and a plurality of second switches alternately to an ON-state, comprising: a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part or all of the plurality of second driving units in accordance with an output voltage.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switches and a second switch alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; and a selection unit stopping part of the plurality of first driving units in accordance with an input/output voltage difference.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a first switch and a plurality of second switches alternately to an ON-state, comprising: a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part or all of the plurality of second driving units in accordance with an input/output voltage difference.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switch and a plurality of second switch alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part of the plurality of first driving units, and part or all of the plurality of second driving units in accordance with a load current.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switches and a plurality of second switch alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part of the plurality of first driving units, and part or all of the plurality of second driving units in accordance with an input voltage.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switches and a plurality of second switches alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part of the plurality of first driving units, and part or all of the plurality of second driving units in accordance with an output voltage.
A control circuit of a switching converter converting an input electric power to an output electric power by setting a plurality of first switch and a plurality of second switch alternately to an ON-state, comprising: a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; and a selection unit stopping part of the plurality of first driving units, and part or all of the plurality of second driving units in accordance with an input/output voltage difference.
A switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; a load current detection unit detecting a load current; and a selection unit stopping part of the plurality of first driving units in accordance with the load current detected by the load current detection unit.
A switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; a load current detection unit detecting a load current; and a selection unit stopping part or all of the plurality of second driving units in accordance with the load current detected by the load current detection unit.
A switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; an input voltage detection unit detecting an input voltage; and a selection unit stopping part of the plurality of first driving units in accordance with the input voltage detected by the input voltage detection unit.
A switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; an input voltage detection unit detecting an input voltage; and a selection unit stopping part or all of the plurality of second driving units in accordance with the input voltage detected by the input voltage detection unit.
A switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; an output voltage detection unit detecting an output voltage; and a selection unit stopping part of the plurality of first driving units in accordance with the output voltage detected by the output voltage detection unit.
A switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; an output voltage detection unit detecting an output voltage; and a selection unit stopping part or all of the plurality of second driving units in accordance with the output voltage detected by the output voltage detection unit.
A switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; a voltage difference detection unit detecting an input/output voltage difference; and a selection unit stopping part of the plurality of first driving units in accordance with the input/output voltage difference detected by the voltage difference detection unit.
A switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; a voltage difference detection unit detecting an input/output voltage difference; and a selection unit stopping part or all of the plurality of second driving units in accordance with the input/output voltage difference detected by the voltage difference detection unit.
A switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; a load current detection unit detecting a load current; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the load current detected by the load current detection unit.
A switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; an input voltage detection unit detecting an input voltage; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the input voltage detected by the input voltage detection unit.
A switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; an output voltage detection unit detecting an output voltage; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the output voltage detected by the output voltage detection unit.
A switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; a voltage difference detection unit detecting an input/output voltage difference; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the input/output voltage difference detected by the voltage difference detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; a load current detection unit detecting a load current; and a selection unit stopping part of the plurality of first driving units in accordance with the load current detected by the load current detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; a load current detection unit detecting a load current; and a selection unit stopping part or all of the plurality of second driving units in accordance with the load current detected by the load current detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; an input voltage detection unit detecting an input voltage; and a selection unit stopping part of the plurality of first driving units in accordance with the input voltage detected by the input voltage detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; an input voltage detection unit detecting an input voltage; and a selection unit stopping part or all of the plurality of second driving units in accordance with the input voltage detected by the input voltage detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; an output voltage detection unit detecting an output voltage; and a selection unit stopping part of the plurality of first driving units in accordance with the output voltage detected by the output voltage detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; an output voltage detection unit detecting an output voltage; and a selection unit stopping part or all of the plurality of second driving units in accordance with the output voltage detected by the output voltage detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a second switch; a plurality of first driving units driving respectively the plurality of first switches; a second driving unit driving the second switch; a voltage difference detection unit detecting an input/output voltage difference; and a selection unit stopping part of the plurality of first driving units in accordance with the input/output voltage difference detected by the voltage difference detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a first switch; a plurality of second switches; a first driving unit driving the first switch; a plurality of second driving units driving respectively the plurality of second switches; a voltage difference detection unit detecting an input/output voltage difference; and a selection unit stopping part or all of the plurality of second driving units in accordance with the input/output voltage difference detected by the voltage difference detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; a load current detection unit detecting a load current; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the load current detected by the load current detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; an input voltage detection unit detecting an input voltage; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the input voltage detected by the input voltage detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; an output voltage detection unit detecting an output voltage; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the output voltage detected by the output voltage detection unit.
An electronic device including a switching converter and a load operated by an output from the switching converter, the switching converter comprising: a plurality of first switches; a plurality of second switches; a plurality of first driving units driving respectively the plurality of first switches; a plurality of second driving units driving respectively the plurality of second switches; a voltage difference detection unit detecting an input/output voltage difference; and a selection unit stopping part of the plurality of first driving units and stopping part or all of the plurality of second driving units in accordance with the input/output voltage difference detected by the voltage difference detection unit.
A switching circuit includes: an A-coil connected to an output terminal; a first A-switch switching electric power outputted via the A-coil; a second A-switch making rectification so as to become an ON-state alternately with the first A-switch; an A-driving unit driving the first A-switch and the second A-switch alternately; a B-coil connected in series to the A-coil; and a first B-switch switching the electric power outputted via the B-coil and the A-coil. (10)
A switching converter includes: an A-coil connected to an output terminal; a first A-switch switching electric power outputted via the A-coil; a second A-switch making rectification so as to become an ON-state alternately with the first A-switch; an A-driving unit driving the first A-switch and the second B-switch alternately; a B-coil connected in series to the A-coil; a first B-switch switching the electric power outputted via the B-coil and the A-coil; a second B-switch making the rectification so as to become an ON-state alternately with the first B-switch; an A-driving unit driving the first B-switch and the second B-switch alternately; and a selection unit causing the A-driving unit and the B-driving unit to drive selectively. (11)
A switching converter according to Note 38, wherein the first A-switch and the second A-switch is set to have a larger capacity than the first B-switch and the second B-switch have, and the selection unit drives the A-driving unit when an output load is higher than a predetermined value and drives the B-driving unit when the output load is equal to or lower than the predetermined value. (12)
A switching converter according to Note 38 or 39, wherein the A-coil may be set to have a larger capacity than the B-coil, and the selection unit drives the A-driving unit when the output load is higher than a predetermined value and drives the B-driving unit when the output load is equal to or lower than the predetermined value. (13)
A switching converter according to Note 40, wherein the A-coil has a lower inductance than the B-coil. (14)
A switching converter according to any one of Notes 38 through 41, wherein the A-driving unit is set to have a larger capacity than the B-driving unit, and the selection unit drives the A-driving unit when the output load is higher than a predetermined value and drives the B-driving unit when the output load is equal to or lower than the predetermined value. (15)
A switching converter according to any one of Notes 38 through 42, wherein the A-coil extends from one terminal of the single coil up to a middle point thereof, and the B-coil extends from the middle point up to the other terminal thereof. (16)
A switching converter according to any one of Notes 38 through 43, wherein the selection unit receives information representing an operating state of a load-sided circuit, and drives the A-driving unit or the B-driving unit in accordance with the information. (17)
A switching converter according to any one of Notes 38 through 44, wherein the selection unit drives the A-driving unit or the B-driving unit in accordance with an output current. (18)
A switching converter includes: a first A-FET having a drain terminal that is connected to an input terminal; a second A-FET having a drain terminal that is connected to a source terminal of the first A-FET, and a source terminal that is connected to the ground; an A-driving unit connected to gate terminals of the first A-FET and of the second A-FET, and driving the first A-FET and the second A-FET alternately; an A-coil having one terminal that is connected to an A-oscillation part to which the source terminal of the first A-FET and the drain terminal of the second A-FET are connected, and having the other terminal that is connected to an output terminal; a first B-FET having a drain terminal that is connected to an input terminal; a second B-FET having a drain terminal that is connected to the source terminal of the first B-FET and a source terminal that is connected to the ground; a B-driving unit connected to gate terminals of the first B-FET and of the second B-FET, and driving the first B-FET and the second B-FET alternately; a B-coil having one terminal that is connected to an B-oscillation part to which the source terminal of the first B-FET and the drain terminal of the second B-FET are connected, and having the other terminal that is connected to A-oscillation part; and a selection unit selectively driving the A-driving unit and the B-driving unit. (19)
An electronic device having a switching converter and a load operating by an output from the switching converter, the switching converter including: an A-coil connected to an output terminal; a first A-switch switching electric power outputted via the A-coil; a second A-switch making rectification so as to become an ON-state alternately with the first A-switch; an A-driving unit driving the first A-switch and the second B-switch alternately; a B-coil connected in series to the A-coil; a first B-switch switching the electric power outputted via the B-coil and the A-coil; a second B-switch making the rectification so as to become an ON-state alternately with the first B-switch; an A-driving unit driving the first B-switch and the second B-switch alternately; and a selection unit causing the A-driving unit and the B-driving unit to drive selectively. (20)
The invention can be applied to all types of electronic devices such as computers, cellular phones, video cameras, network devices, audio devices, etc. that utilize the DC power.
The disclosures of Japanese patent application No. JP2005-080640 filed on Mar. 18, 2005, No. JP2006-051018 filed on Feb. 27, 2006 and U.S. patent application Ser. No. 11/239,364 filed on Sep. 30, 2005 including the specification, drawings and abstract are incorporated herein by reference.
US6429633 Aug 27, 1999 Aug 6, 2002 Matsushita Electric Industrial Co., Ltd. Switching regulator and LSI system
US20020054499 Dec 26, 2001 May 9, 2002 Tdk Corporation Power conversion apparatus
US20020136030 Nov 30, 2001 Sep 26, 2002 Hitachi, Ltd. DC-DC converter and control circuit therefor
US20030185022 Feb 21, 2003 Oct 2, 2003 Hiroto Ohishi Power circuit of image formation apparatus and method of controlling power source of image formation apparatus
US20030185025 Jan 15, 2003 Oct 2, 2003 Ko Takemura Multiphase DC/DC converter
US20040183510 Apr 5, 2004 Sep 23, 2004 Marvell World Trade Ltd. Power array system and method
CN1383605A Apr 26, 2001 Dec 4, 2002 Tdk股份有限公司 Power converting device
JP2003284333A Title not available
JP2003319645A Title not available
JP2003319649A Title not available
JPH07222438A Title not available
KR100702278B1 Title not available
WO2003032477A2 Oct 15, 2002 Apr 17, 2003 Northeastern University Integrated magnetics for a dc-dc converter with flexible output inductor
1 Chinese Patent Office Action, mailed Jun. 13, 2008 and issued in corresponding Chinese Patent Application No. 200610064895.0.
2 European Search Report dated Jan. 19, 2010 for corresponding European Patent Application No. 06251408.8.
3 Japanese Notice of Reason for Rejection issued in Japanese Patent Application No. 2006-051018 (mailed on Jan. 11, 2011).
4 Notice of Allowance for Patent dated Sep. 6, 2007 in corresponding Korean Application No. 10-2006-0024985.
5 Office Action issued Oct. 30, 2006 is parent U.S. Appl. No. 11/239,364.
6 Partial European Search Report mailed Oct. 30, 2009 and issued in corresponding European Patent Application 06251408.8.
7 U.S. Appl. No. 11/239,364, filed Sep. 30, 2005, Mitsuo Saeki.
8 U.S. Appl. No. 11/377,213, filed Mar. 17, 2006, Mitsuo Saeki.
US9209691 * May 10, 2013 Dec 8, 2015 Adaptive Digital Power, Inc. Fast transient buck regulator with dynamic charge/discharge capability
US9712051 * Apr 26, 2016 Jul 18, 2017 Arctic Sand Technologies, Inc. Power converter with modular stages
US20160322894 * Apr 26, 2016 Nov 3, 2016 Arctic Sand Technologies, Inc. Power converter with modular stages connected by floating terminals
International Classification G05F1/575, G05F1/59