Disclosure of Invention
The purpose of the invention is as follows: the switched capacitor DC-DC converter is in a multi-voltage-domain composite feedback mode, and the switched capacitor DC-DC converter can work in a working mode with optimal efficiency all the time, improves the load range and reduces the output voltage ripple.
The technical scheme is as follows: the invention provides a switched capacitor DC-DC converter in a multi-voltage domain load feedback mode, which is used for converting the power supply voltage of a load and comprises a power supply switching module, a control clock generating module, a level detection feedback module, a low-power-consumption voltage reference circuit and a load current self-adaptive feedback module;
the first voltage end of the power supply switching module, the power end of the capacitor module, the power end of the low-power-consumption voltage reference circuit and the power end of the load self-current adaptive feedback module are respectively butted to serve as an input voltage V of a first voltage domainin(ii) a The voltage output end of the load current self-adaptive feedback module is used as the output voltage V of a third voltage domainoutAnd respectively connected with the second voltage input end of the power supply switching module, the power end of the level detection feedback module and the load RLPositive electrode of (2), load RLThe negative electrode of (2) is grounded;
a first voltage output end of the low-power-consumption voltage reference circuit is connected with a positive input end of the level detection feedback module, and a second voltage output end of the low-power-consumption voltage reference circuit is connected with a first input end of the load current self-adaptive feedback module; the output end of the level detection feedback module is connected with the control clock generation moduleThe output end of the power supply switching module is connected with the voltage input end of the control clock generation module, and the output end of the control clock generation module is connected with the input end of the capacitor module; the output of the capacitor module is output as a capacitor module output V of the second voltage domainscThe negative input end of the level detection feedback module, the second input end of the load current self-adaptive feedback module and the third voltage input end of the power supply switching module are respectively connected; and the current output end of the load current self-adaptive feedback module is connected with the feedback signal input end of the control clock generation module.
Further comprises a load capacitor CL(ii) a The load capacitor CLIs connected to a load RLPositive electrode of (2), load capacitance CLThe other end of the connecting rod is connected with the anode and the cathode of the load; the negative pole of the load is grounded.
The power supply switching module comprises a stable signal generating module, a first phase inverter, a first switch and a second switch;
the input end of the stable signal generating module forms a third input end of the power supply switching module; the output end of the stable signal generating module is connected with the input end of the first phase inverter and the control end of the first switch, and one end of the first switch forms a first voltage input end of the power supply switching module; the output end of the first phase inverter is connected with the control end of the second switch, and one end of the second switch forms a second voltage input end of the power supply switching module; the other end of the first switch is connected with the other end of the second switch to form an output end of the power supply switching module.
The load current adaptive feedback module comprises: the device comprises an error amplifier op1, a master-slave power tube array and a load self-adaptive bias and feedback current generation module;
the width-length ratio of the master power tube array to the slave power tube array is 1: n, wherein N is an integer greater than 1, and the master power tube and the slave power tube comprise a master power tube and a slave power tube; the power supply end of the error amplifier op1 forms the power supply end of the load current self-adaptive feedback module, the positive input end of the error amplifier op1 forms the first input end of the load current self-adaptive feedback module, and the output end of the error amplifier op1 is connected with the grid electrode of each power tube in the master-slave power tube array; the drain electrode of the main power tube is connected with the drain electrode of the auxiliary power tube, and a connection point forms a second input end of the load current self-adaptive feedback module; the source electrode of the main power tube, the negative input end of the error amplifier op1 and the first input end of the load self-adaptive bias and feedback current generation module are connected, and the connection point forms the voltage output end of the load self-adaptive feedback module; the first output end of the load self-adaptive bias and feedback current generation module forms the current output end of the load current self-adaptive feedback module;
the source electrode of the slave power tube is connected with the second input end of the load self-adaptive bias and feedback current generation module; and the second output end of the load self-adaptive bias and feedback current generation module is connected with the bias current input end of the error amplifier.
The master power tube is an NMOS tube MN1, and the slave power tube is an NMOS tube MN 2;
the load adaptive bias and feedback current generation module comprises: NMOS transistor MN3, NMOS transistor MN4, NMOS transistor MN5, NMOS transistor MN6, NMOS transistor MN7, NMOS transistor MN8, PMOS transistor MP1, PMOS transistor MP2, PMOS transistor MP3, PMOS transistor MP4, and compensation current source IC1;
The source electrode of the PMOS pipe MP1 forms a first input end of the load self-adaptive bias and feedback current generation module; the source electrode of the PMOS pipe MP2 forms a second input end of the load self-adaptive bias and feedback current generation module; the drain electrode of the PMOS tube MP1 is respectively connected with the drain electrode of the NMOS tube MN3, the grid electrode of the NOMS tube MN3, the grid electrode of the NOMS tube MN4 and the grid electrode of the NOMS tube MN 5; the grid electrode of the PMOS tube MP1 is respectively connected with the grid electrode of the PMOS tube MP2, the drain electrode of the PMOS tube MP2 and the drain electrode of the NMOS tube MN 4;
the drain electrode of the NOMS tube MN5 is respectively connected with the drain electrode of the PMOS tube MP3, the grid electrode of the PMOS tube MP3 and the grid electrode of the PMOS tube MP 4; the source electrode of the PMOS transistor MP3, the source electrode of the PMOS transistor MP4 and the compensation current source IC1Is connected to an input voltage V as a first voltage domainin(ii) a Drain electrode of PMOS transistor MP4 and compensation current source IC1The output end of the NMOS transistor, the drain electrode of the MN6 of the NMOS transistor, the grid electrode of the MN6 of the NMOS transistor, the grid electrode of the MN7 of the NMOS transistor and the grid electrode of the MN8 of the NMOS transistor are connected; the drain electrode of the NMOS tube MN7 forms a second output end of the load self-adaptive bias and feedback current generation module(ii) a The drain electrode of the NMOS tube MN8 forms the current output end of the load current self-adaptive feedback module;
the source electrode of the NMOS transistor MN3, the source electrode of the NMOS transistor MN4, the source electrode of the NMOS transistor MN5, the source electrode of the NMOS transistor MN6, the source electrode of the NMOS transistor MN7 and the source electrode of the NMOS transistor MN8 are connected, and the connection point is grounded.
The control clock generation module comprises a current-controlled oscillator, a feedback signal processing module, two non-overlapping clock processing modules and a level conversion circuit;
the first input end of the current-controlled oscillator, the third input end of the feedback signal processing module and the third input end of the two non-overlapped clocks are connected, and the connection point forms the voltage input end of the control clock generation module; the second input end of the current-controlled oscillator forms a feedback signal input end of the control clock generation module, the output end of the current-controlled oscillator is connected with the first input end of the feedback signal processing module, and the second input end of the feedback signal processing module forms a control signal input end of the control clock generation module; the first output end and the second output end of the feedback signal processing module are respectively connected with the first input end and the second input end of the two non-overlapped clocks in a one-to-one correspondence manner; the first output end and the second output end of the two non-overlapped clocks are respectively connected with the first input end and the second input end of the level conversion circuit in a one-to-one correspondence manner, and the output end of the level conversion circuit forms the output end of the control clock generation module;
the current-controlled oscillator is used for collecting feedback current output by the load current self-adaptive feedback module and generating a periodic signal with frequency in direct proportion to the magnitude of the feedback current; the feedback signal processing module is used for processing a periodic signal with the frequency which is generated by the current-controlled oscillator and is in direct proportion to the magnitude of the feedback current according to the feedback signal of the comparator, sequentially outputting the processing result to the two non-overlapping clock generating modules and the level converting circuit for processing, and outputting the processing result to the capacitor module.
The feedback signal processing module comprises a second inverter, a third inverter, a fourth inverter and a NAND gate;
one end of the second phase inverter forms a second input end of the feedback signal processing module, the other end of the second phase inverter is connected with one end of the third phase inverter, the other end of the third phase inverter is connected with an A end of the NAND gate, a B end of the NAND gate forms a first input end of the feedback signal processing module, a C end of the NAND gate is connected with one end of the fourth phase inverter, the connection point forms a first output end of the feedback signal processing module, and the other end of the fourth phase inverter forms a second output end of the feedback signal processing module.
The current-controlled oscillator is a current starvation type current-controlled oscillator; the current starvation type current-controlled oscillator comprises a PMOS tube MP5, a PMOS tube MP6, a PMOS tube MP7, an NMOS tube MN9, an NMOS tube MN10, a fifth phase inverter, a sixth phase inverter and a plurality of units A;
each A unit comprises a PMOS pipe MP8, a seventh inverter and an NMOS pipe MN 11; the drain electrode of the PMOS tube MP8 is connected with the first input end of the seventh inverter, and the second input end of the seventh inverter is connected with the drain electrode of the NMOS tube MN 11; the seventh phase inverters in the units A are sequentially connected with the third input end through the output ends and the third input ends of the seventh phase inverters; the third input end of the seventh inverter in the A unit at the head end is connected with the output end of the seventh inverter in the A unit at the tail end and the third input end of the sixth inverter; the output end of the sixth inverter is connected with the third input end of the fifth inverter;
the source electrode of the PMOS tube MP5, the source electrode of the PMOS tube MP6, the source electrode of the PMOS tube MP8 in each A unit, the source electrode of the PMOS tube MP7 and the first input end of the fifth inverter are connected, and the connection point forms the first input end of the current starvation type current-controlled oscillator; the grid electrode of the PMOS tube MP5, the grid electrode of the PMOS tube MP6, the grid electrode of the PMOS tube MP8 in each A unit, the grid electrode of the PMOS tube MP7, the drain electrode of the PMOS tube MP5, the source electrode of the NMOS tube MN9, the source electrode of the NMOS tube MN10, the source electrode of the NMOS tube MN11 in each A unit and the second input end of the fifth phase inverter are connected, and the connecting point forms the second input end of the current starvation type current-controlled oscillator; the output end of the fifth inverter forms the output end of the current starvation type current-controlled oscillator;
the drain electrode of the PMOS tube MP6, the drain electrode of the NMOS tube MN9, the gate electrode of the NMOS tube MN9, the gate electrode of the NMOS tube MN11 in each A unit and the gate electrode of the NMOS tube MN10 are connected.
Has the advantages that: compared with the prior art, the switched capacitor DC-DC converter in the multi-voltage domain composite feedback mode can adaptively optimize the switching frequency and the offset of the error amplifier according to the load change, dynamically adjust the equivalent clock frequency input to the capacitor module according to the change of the output Vsc of the capacitor module in the second voltage domain, realize that the switched capacitor DC converter always works in the working mode with the optimal efficiency under different load conditions, effectively improve the load range of the converter in the composite feedback mode, and reduce the ripple of the output voltage.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Referring to fig. 1, the switched capacitor DC-DC converter of the multi-voltage domain composite feedback mode provided by the present invention includes a power supply switching module, a control clock generating module, a level detection feedback module, a low power consumption voltage reference circuit, and a load current adaptive feedback module; the level detection feedback module is composed of a comparator;
the switched capacitor DC-DC converter in the multi-voltage domain composite feedback mode comprises three voltage domains: input voltage VinFor the first voltage domain, the capacitor module outputs VscIn a second voltage domain, outputting a voltage VoutA third voltage domain;
first voltage terminal and power supply switching moduleThe power end of the container module, the power end of the low-power-consumption voltage reference circuit and the power end of the load self-current adaptive feedback module are respectively butted with an input voltage V serving as a first voltage domainin(ii) a The voltage output end of the load current self-adaptive feedback module is used as the output voltage V of a third voltage domainoutAnd respectively connected with the second voltage input terminal of the power supply switching module, the power supply terminal of the level detection feedback module, the anode of the load, and the load capacitor CLOne end of (a); negative pole of load and load capacitance CLThe other end of which is connected and grounded.
The first voltage output end of the low-power-consumption voltage reference circuit outputs a first reference voltage Vref1The first voltage output end is connected with the positive input end of the level detection feedback module, and the second voltage output end of the low-power-consumption voltage reference circuit outputs a second reference voltage Vref2The second voltage output end is connected with the first input end of the load current self-adaptive feedback module; the output end of the level detection feedback module is connected with the signal control end of the control clock generation module, the output end of the power supply switching module is connected with the voltage input end of the control clock generation module, and the output end of the control clock generation module is connected with the input end of the capacitor module; the capacitor module is controlled by a control clock output by the control clock generation module, periodically switched between a charging state and a discharging state, and generates a level V capable of supplying powerscNamely: the output of the capacitor module is output as a capacitor module output V of the second voltage domainscThe negative input end of the level detection feedback module, the second input end of the load current self-adaptive feedback module and the third voltage input end of the power supply switching module are respectively connected; v output from the output of the capacitor modulescThe second input end of the load current self-adaptive feedback module is connected with the second input end of the load current self-adaptive feedback module and is used for supplying power to a master power tube array and a slave power tube array in the load current self-adaptive feedback module; according to capacitor module output VscThe level state provides different power supply levels to the control clock generation module in different stable circuit starting states; and the current output end of the load current self-adaptive feedback module is connected with the feedback signal input end of the control clock generation module.
Referring to fig. 2, the power supply switching module includes a stable signal generating module, a first inverter, a first switch, and a second switch;
the input end of the stable signal generating module forms a third input end of the power supply switching module; the output end of the stable signal generating module is connected with the input end of the first phase inverter and the control end of the first switch, and one end of the first switch forms a first voltage input end of the power supply switching module; the output end of the first phase inverter is connected with the control end of the second switch, and one end of the second switch forms a second voltage input end of the power supply switching module; the other end of the first switch is connected with the other end of the second switch to form an output end of the power supply switching module.
Referring to fig. 2, the control clock generating module includes a current-controlled oscillator, a feedback signal processing module, two non-overlapping clock processing modules, and a level shift circuit, which are electrically connected in sequence;
the first input end of the current-controlled oscillator, the third input end of the feedback signal processing module and the third input end of the two non-overlapped clocks are connected, and the connection point forms the voltage input end of the control clock generation module; the second input end of the current-controlled oscillator forms a feedback signal input end of the control clock generation module, the output end of the current-controlled oscillator is connected with the first input end of the feedback signal processing module, and the second input end of the feedback signal processing module forms a control signal input end of the control clock generation module; the first output end and the second output end of the feedback signal processing module are respectively connected with the first input end and the second input end of the two non-overlapped clocks in a one-to-one correspondence manner; the first output end and the second output end of the two non-overlapped clocks are respectively connected with the first input end and the second input end of the level conversion circuit in a one-to-one correspondence mode, and the output end of the level conversion circuit forms the output end of the control clock generation module.
The current-controlled oscillator is used for collecting feedback current output by the load current self-adaptive feedback module and generating a periodic signal with the frequency in direct proportion to the magnitude of the feedback current; the feedback signal processing module is used for processing a periodic signal with the frequency which is generated by the current-controlled oscillator and is in direct proportion to the magnitude of the feedback current according to the feedback signal of the comparator, sequentially outputting the processing result to the two non-overlapping clock generating modules and the level converting circuit for processing, and outputting the processing result to the capacitor module.
The feedback signal processing module comprises a first inverter, a second inverter, a third inverter and a NAND gate;
one end of the first phase inverter forms a second input end of the feedback signal processing module, the other end of the first phase inverter is connected with one end of the second phase inverter, the other end of the second phase inverter is connected with an A end of the NAND gate, a B end of the NAND gate forms a first input end of the feedback signal processing module, a C end of the NAND gate is connected with one end of the third phase inverter, the connection point forms a first output end of the feedback signal processing module, and the other end of the third phase inverter forms a second output end of the feedback signal processing module.
Referring to fig. 3, the load current adaptive feedback module includes: the device comprises an error amplifier op1, a master-slave power tube array, a load self-adaptive bias and feedback current generation module and an adjustable current source; the function of the current collector is to collect load current and pass 1/N of the load current through a compensation current IC1After compensation processing, the current is used as micro current and feedback current of an error amplifier; the width-length ratio of the master power tube array to the slave power tube array is 1: n, where N is an integer greater than 1, and in this embodiment, N takes the value of 1000; the master-slave power tube comprises a master power tube MN1 and a slave power tube MN 2.
The power supply end of the error amplifier op1 forms the power supply end of the load current self-adaptive feedback module, the positive input end of the error amplifier op1 forms the first input end of the load current self-adaptive feedback module, and the output end of the error amplifier op1 is connected with the grid electrode of each power tube in the master-slave power tube array; the drain electrode of the main power tube MN1 is connected with the drain electrode of the auxiliary power tube MN2, and the connection point forms a second input end of the load current self-adaptive feedback module; the source electrode of the main power tube MN1, the negative input end of the error amplifier op1 and the first input end of the load self-adaptive bias and feedback current generation module are connected, and the connection point forms the voltage input end of the load self-adaptive feedback module; the first output end of the load self-adaptive bias and feedback current generation module forms a current output end of the load current self-adaptive feedback module.
The source electrode of the slave power tube is connected with the second input end of the load self-adaptive bias and feedback current generation module; the second output end of the load self-adaptive bias and feedback current generation module is connected with the control end of the adjustable current source, the input end of the adjustable current source is connected with the error amplifier op1, and the output end of the adjustable current source is grounded.
In this embodiment, the master power transistor is an NMOS transistor MN1, and the slave power transistor is an NMOS transistor MN 2.
The load adaptive bias and feedback current generation module comprises: NMOS transistor MN3, NMOS transistor MN4, NMOS transistor MN5, NMOS transistor MN6, NMOS transistor MN7, NMOS transistor MN8, PMOS transistor MP1, PMOS transistor MP2, PMOS transistor MP3, PMOS transistor MP4, and compensation current source IC1;
The source electrode of the PMOS pipe MP1 forms a first input end of the load self-adaptive bias and feedback current generation module; the source electrode of the PMOS pipe MP2 forms a second input end of the load self-adaptive bias and feedback current generation module; the drain electrode of the PMOS tube MP1 is respectively connected with the drain electrode of the NMOS tube MN3, the grid electrode of the NOMS tube MN3, the grid electrode of the NOMS tube MN4 and the grid electrode of the NOMS tube MN 5; the grid electrode of the PMOS tube MP1 is respectively connected with the grid electrode and the drain electrode of the PMOS tube MP2 and the drain electrode of the NMOS tube MN 4.
The drain electrode of the NOMS transistor MN5 is respectively connected with the drain electrode of the PMOS transistor MP3, the grid electrode of the PMOS transistor MP3 and the grid electrode of the PMOS transistor MP 4.
The source electrode of the PMOS transistor MP3, the source electrode of the PMOS transistor MP4 and the compensation current source IC1Is connected to an input voltage V as a first voltage domainin。
Drain electrode of PMOS transistor MP4 and compensation current source IC1The output end of the NMOS transistor, the drain electrode of the MN6 of the NMOS transistor, the grid electrode of the MN6 of the NMOS transistor, the grid electrode of the MN7 of the NMOS transistor and the grid electrode of the MN8 of the NMOS transistor are connected; the drain electrode of the NMOS tube MN7 forms the output end of the load self-adaptive bias and feedback current generation module; the drain electrode of the NMOS tube MN8 forms the current output end of the load current self-adaptive feedback module;
the source electrode of the NMOS transistor MN3, the source electrode of the NMOS transistor MN4, the source electrode of the NMOS transistor MN5, the source electrode of the NMOS transistor MN6, the source electrode of the NMOS transistor MN7 and the source electrode of the NMOS transistor MN8 are connected, and the connection point is grounded.
Referring to fig. 4, the current starved current controlled oscillator controlling the clock generation module includes: PMOS pipe MP5, PMOS pipe MP6, PMOS pipe MP7, NMOS pipe MN9, NMOS pipe MN10, fifth inverter, sixth inverter, and a plurality of A units.
Each A unit comprises a PMOS pipe MP8, a seventh inverter and an NMOS pipe MN 11; the drain electrode of the PMOS tube MP8 is connected with the first input end of the seventh inverter, and the second input end of the seventh inverter is connected with the drain electrode of the NMOS tube MN 11; the seventh phase inverters in the units A are sequentially connected with the third input end through the output ends and the third input ends of the seventh phase inverters; the third input end of the seventh inverter in the A unit at the head end is connected with the output end of the seventh inverter in the A unit at the tail end and the third input end of the sixth inverter; and the output end of the sixth inverter is connected with the third input end of the fifth inverter.
The source electrode of the PMOS tube MP5, the source electrode of the PMOS tube MP6, the source electrode of the PMOS tube MP8 in each A unit, the source electrode of the PMOS tube MP7 and the first input end of the fifth inverter are connected, and the connection point forms the first input end of the current starvation type current-controlled oscillator; the grid electrode of the PMOS tube MP5, the grid electrode of the PMOS tube MP6, the grid electrode of the PMOS tube MP8 in each A unit, the grid electrode of the PMOS tube MP7, the drain electrode of the PMOS tube MP5, the source electrode of the NMOS tube MN9, the source electrode of the NMOS tube MN10, the source electrode of the NMOS tube MN11 in each A unit and the second input end of the fifth phase inverter are connected, and the connecting point forms the second input end of the current starvation type current-controlled oscillator; the output end of the fifth inverter forms the output end of the current starvation type current-controlled oscillator;
the drain electrode of the PMOS tube MP6, the drain electrode of the NMOS tube MN9, the gate electrode of the NMOS tube MN9, the gate electrode of the NMOS tube MN11 in each A unit and the gate electrode of the NMOS tube MN10 are connected.
The three voltage domain working modes of the embodiment of the invention are as follows: first of all from an input voltage V as a first voltage domaininFor all circuit blocks except the comparator, the comparator is directly powered by VOUTAnd (5) supplying power. The capacitor module is clocked to generate a capacitor module output V as a second voltage domainSCIn combination with VSCThe load current self-adaptive feedback module supplies power to the master power tube and the slave power tube in the load current self-adaptive feedback module, and the load current self-adaptive module supplies power to the master power tube and the slave power tube in the load current self-adaptive feedback moduleSCFurther converted to an output voltage V as a third voltage domainOUTRealizing the input voltage V of the switched capacitor converterINTo an output voltage VOUTThe conversion of (1). Meanwhile, when the power supply switching module detects the second voltage node V, the power supply switching module supplies power to the power supply switching moduleSCAfter the voltage is stabilized, outputting a stable READY signal, and controlling the supply voltage of the clock generation module from the input voltage V by the READY signal through a control switch tubeINSwitch to VOUTTherefore, the power supply voltage is reduced, and the power consumption of the circuit is reduced.
Level sensing feedback As shown in FIG. 2, the comparator continuously monitors the capacitor module output Vsc, and the first output reference voltage V generated by the low-power voltage reference circuitref1Comparison when V isSCWhen the voltage is too large, the output end of the comparator outputs low level to the control clock generation module to shield clock pulse, so that the switched capacitor network outputs VSCDescending; vSCWhen smaller, the comparator outputs a high level, not masking the clock signal.
The load self-adaptive feedback module is shown in fig. 3, and has the functions that the load self-adaptive feedback module detects the magnitude of load current through a master power tube and a slave power tube, 1/N of the load current is collected and used through the action of an error amplifier, one part of the load self-adaptive feedback module is used as tail current of the error amplifier to realize load self-bias, and the load self-bias is used as feedback current after compensation of a compensation current source to control the frequency of a controlled oscillator. The frequency size adaptive to the load can be provided under different loads, and the load range is expanded. Since the NMOS is used as the master and slave power transistors in this example, a self-bias circuit is added to fix the source voltages of the master and slave power transistors, and the output of the error amplifier adjusts the gate voltage thereof, thereby establishing a current mirror function. Since the characteristics of the self-bias circuit require the addition of an additional start-up circuit, it is common and not illustrated in the drawings. It should be noted that the present invention includes the case of using NMOS as the master-slave power transistor but is not limited to NMOS.
The invention reduces the control circuit loss of the switch capacitor DC-DC converter through a multi-voltage domain technology, and improves the conversion efficiency under different load conditions under the wide load condition through a composite feedback mode.
Specific embodiments of the present invention have been described above in detail. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.