DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 06/19/2024 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Specification
The disclosure is objected to because of the following informalities:
Paragraph 0002, line 4, recites “amount of voltage/current of the required by the chipset changes” should be changed “the amount of voltage/current required by the chipset changed”.
Paragraph 0017, line 5, recites “can be benefit from” should be changed to “can benefit from”.
Paragraph 0017, line 5, recites “with fewer, or more, voltage” should be changed to “with fewer or more voltage”.
Paragraph 0023, lines 4-5, recites “The REFIN signal and below TEMP are” should be changed to “The REFIN signal and a TEMP signal are”.
Paragraph 0028, line 3, recites “may varying” should be changed to “may vary”.
Paragraph 0035, lines 3-4, recites “maintains the efficiency mode at block 325” which should be changed to “maintains the efficiency mode at block 315”.
Paragraph 0043, line 4, recites “in response” should be changed to “In response”.
Paragraph 0050, line 2, recites “then step down” should be changed to “then steps down”.
Appropriate correction is required.
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Claim Objections
Claims 1, 7 and 14 are objected to because of the following informalities:
Claim 1, lines 5-6, recites “at least one switch for changing the input voltage from a higher voltage value to a lower voltage value used when performing PWM using the PWM signal” and is grammatically awkward due to the word “used”. The Examiner suggests the following change “at least one switch for changing the input voltage from using a higher voltage value to a lower voltage value when performing PWM using the PWM signal”.
Claim 7, line 3, recites “both been below respective thresholds” is confusing as it seems to imply two different thresholds. This should be amended to recites “both been below a current threshold and a voltage threshold, respectively,”.
Claim 14, line 3, recites “both been below respective thresholds” is confusing as it seems to imply two different thresholds. This should be amended to recites “both been below a current threshold and a voltage threshold, respectively,”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 6, 13 and 16-18 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 6, claim 6 depends upon claims 5, 4 and 1 and recites, inter alia, “a second power stage, wherein the higher voltage value or a higher current value is used to perform PWM in both the second power stage and the power stage in a 2-phase CCM, wherein the first mode is a 1-phase CCM where the higher voltage value is used to perform PWM in the power stage but not in the second power stage.” Claim 1 establishes a higher voltage value is used as the input voltage when performing PWM, Claim 4 establishes that the first mode is when the higher voltage value is used as the input voltage and Claim 5 establishes that during the first mode continuous current mode (CCM) is used. The first issue with Claim 6 is that it introduces a higher current value being used which is unclear as to where this current is coming from or how it will be used to perform PWM since up till this claim only a higher input voltage was being used. For purposes of examination the Examiner will ignore the limitation of a higher current value due to the ‘or’ clause being present but the claims should be amended to remedy this issue. The second issue is with the language of “wherein the higher voltage value or a higher current value is used to perform PWM in both the second power stage and the power stage in a 2-phase CCM” which is unclear as to whether the second power stage being claimed also switches between the higher voltage value and lower voltage value or is only used when the higher voltage value is present. Applicant’s Disclosure Paragraph 0019 seems to indicate that the second stage is only used in high power situations thus making it reasonable to assume that the claims probably meant to say “wherein when the higher voltage value is used then the PWM control performs PWM in both the second power stage and the power in a 2-phase CCM” therefore the Examiner has taken this interpretation for purposes of examination for this portion of claim 6.
Regarding claim 13, Claim 13 recites similar claim language to that which is recited in claim 6 therefore the rejection for claim 13 can be viewed as the same one provided for claim 6 above as well as the interpretation taken by the Examiner for purposes of examination.
Regarding claim 16, claim 16 depends upon claim 15 and recites, inter alia, “wherein monitoring the output of the power stage comprises monitoring both an output current and an output voltage of the power stage to determine whether the output current and the output voltage are below respective thresholds”. Claim 15 establishes that enabling a first mode or second mode comprises comparing an output with “a threshold” and “an output” indicating a singular threshold value while claim 16 recites that multiple thresholds are present which contradicts with what claim 15 has established. After reviewing the disclosure for purposes of examination the Examiner has taken the interpretation that both an output current and an output voltage are monitored. Furthermore, claim 16 does not define what “respective thresholds” refers to exactly does it mean two different thresholds a current one and a voltage one or are there more than one threshold for each one. Claims 7 and 14 recited similar language and the disclosure seemed to point to the respective thresholds referring to “a current threshold” and “a voltage threshold” being compared to an output current and an output voltage, therefore that is the interpretation taken by the Examiner when examining claim 16.
Regarding claims 17 and 18, claims 17 and 18 depend upon claim 16 and therefore inherit the deficiencies of claim 16 as they do not remedy the issues raised against claim 16. Furthermore, claim 18 also uses the language of “respective thresholds” which is unclear language. Therefore, for purposes of examination the Examiner has interpreted this limitation as “the current threshold and the voltage threshold, respectively”.
Claim Rejections
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim 1-4, 8-11, 15-16 and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Maxim Integrated (“24V Input, 500mA Buck Regulator with Dual-Input Power MUX – MAX77756 Data Sheet”) in view of Von Novak (US 2019/0103766 A1).
Regarding claim 1, Maxim Integrated teaches a voltage regulator (Page 14 Functional Diagram has been annotated as Annotated Figure 1A below for purposes of clarity; Annotated Figure 1A), comprising: a pulse width modulation (PWM) controller (Annotated Figure 1A Component SC; Figure 1 on Page 16 shows Component SC in detail which comprises a PWM comparator to generate the control signals; Page 15 Right Column explains that the controller is a PWM based controller); and a power stage (Annotated Figure 1A Component PS) configured to receive a PWM signal from the PWM controller (Annotated Figure 1A Component SC outputs signals to control Components Q1 and Q2; Figure 1 shows that Components Q1 and Q2 receive a PWM signal) in order to step-down an input voltage (Annotated Figure 1A Component Buck within Component SC is a step down converter; Annotated Figure 1A Component DC Input 1 or DC Input 2), wherein the power stage includes at least one switch (Annotated Figure 1A Component SU) for changing the input voltage (Annotated Figure 1A Component SU changes the input voltage between DC input 1 and DC input 2 based on which switch between Components S1 and S2 is active) from a lower voltage value to a higher voltage value used when performing PWM using the PWM signal (Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage shows that the higher input voltage is used as the input voltage for Components Q1 and Q2 which are controlled by a PWM signal).
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Maxim Integrated does not teach changing the input voltage from a higher voltage value to a lower voltage value.
Von Novak teaches a multiple input single inductor power converter (Figure 6A), comprising: at least one switch supply unit (Figure 6A Component 660) comprising a first switch coupled to a first input voltage (Figure 6A Component 660 Middle Switch) that provides a higher voltage value (Figure 6A Component WP PP is the voltage connected with the middle switch; FIG. 7 is an example of an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources; Figure 7 shows that WP PP is set to a voltage value of 5V in the first row); a second switch coupled to a second input voltage (Figure 6A Component 660 Top Switch) that provides a lower voltage value (Figure 7A Component WP coil is the voltage connected with the top switch; Figure 7 shows WP coil is set to a voltage of 2.5 V in the first row which makes it lower than the voltage of Component WP PP); a control unit (Paragraph 0059 “the input switches 660 and the output switches 665 are controlled by a controller (e.g., PMIC 625) implementing a control algorithm configured to enhance efficiency of the power conversion of power conversion circuit 600”) configured to change the input voltage to the lower voltage from the higher voltage (Figure 7 top row shows that when the output voltage required is 1.1V-1.8V WP coil is connected and not WP PP) or the higher voltage to the lower voltage based on the output voltage demand of the load (Figure 7 top row shows that when the output voltage required is 3.3V-5V then WP PP is connected; Paragraphs 0057-0064 highlights that the voltage is selected based on efficiency and the load demands).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Maxim Integrated to incorporate a control scheme of selecting a lower voltage source or a higher voltage source based on load conditions as taught by Von Novak. The advantage of this design is that the buck converter can be utilized more efficiently instead of trying to step down a higher voltage in situations where a light load operation is needed thus reducing switching loss and enhancing the efficiency of the overall system.
Regarding claim 2, Maxim Integrated and Von Novak teach all the limitations of claim 1. Maxim Integrated further teaches wherein the at least one switch (Annotated Figure 1A Component SU) comprises a first switch (Annotated Figure 1A Component S1) coupled to a first input voltage (Annotated Figure 1A Component DC Input 1) that provides the higher voltage value (Annotated Figure 1A Component S1 being connected would indicate it is the higher voltage; Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”) and a second switch (Annotated Figure 1A Component S2) coupled to a second input voltage (Annotated Figure 1A Component DC Input 2) that provides the lower voltage value (Annotated Figure 1A Component S2 being disconnected would indicate a lower voltage; Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”).
Regarding claim 3, Maxim Integrated and Von Novak teach all the limitations of claim 2. Maxim Integrated further teaches wherein the power stage (Annotated Figure 1A Component PS) further comprises: a third switch coupled to both the first and second switches (Annotated Figure 1A Component Q1 is connected to both Components S1 and S2), wherein the third switch is controlled based on the PWM signal to perform PWM (Annotated Figure 1A Component Q1 is controlled by the step down control unit shown in Figure 1 of Page 16 which shows a PWM comparator is used to generate PWM signals to control Q1 and Q2 with a PWM control scheme) using the higher voltage value (Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage shows that the higher input voltage is used by the buck converter).
Maxim Integrated does not teach using the lower voltage value.
Von Novak teaches a multiple input single inductor power converter (Figure 6A), comprising: at least one switch supply unit (Figure 6A Component 660) comprising a first switch coupled to a first input voltage (Figure 6A Component 660 Middle Switch) that provides a higher voltage value (Figure 6A Component WP PP is the voltage connected with the middle switch; FIG. 7 is an example of an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources; Figure 7 shows that WP PP is set to a voltage value of 5V in the first row); a second switch coupled to a second input voltage (Figure 6A Component 660 Top Switch) that provides a lower voltage value (Figure 7A Component WP coil is the voltage connected with the top switch; Figure 7 shows WP coil is set to a voltage of 2.5 V in the first row which makes it lower than the voltage of Component WP PP); a control unit (Paragraph 0059 “the input switches 660 and the output switches 665 are controlled by a controller (e.g., PMIC 625) implementing a control algorithm configured to enhance efficiency of the power conversion of power conversion circuit 600”) configured to change the input voltage to the lower voltage from the higher voltage (Figure 7 top row shows that when the output voltage required is 1.1V-1.8V WP coil is connected and not WP PP) or the higher voltage to the lower voltage based on the output voltage demand of the load (Figure 7 top row shows that when the output voltage required is 3.3V-5V then WP PP is connected; Paragraphs 0057-0064 highlights that the voltage is selected based on efficiency and the load demands), wherein the voltage selected whether that be the higher one or the lower one is used by a power converter (Figure 6A Component 650 is operated with the inductor as a converter and uses the input voltage that is selected for conversion; Paragraphs 0059, 0062 and 0065).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Maxim Integrated to incorporate a control scheme of selecting a lower voltage source or a higher voltage source based on load conditions as taught by Von Novak. The advantage of this design is that the buck converter can be utilized more efficiently instead of trying to step down a higher voltage in situations where a light load operation is needed thus reducing switching loss and enhancing the efficiency of the overall system.
Regarding claim 4, Maxim Integrated and Von Novak teach all the limitations of claim 1. Maxim Integrated further teaches wherein the PWM controller is configured to monitor at least one of an output current or an output voltage of the power stage to perform PWM in a first mode having the higher voltage (Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage shows that the higher input voltage is used by the buck converter; Annotated Figure 1A Component SC is seen in detail in Figure 1 of Page 16; Figure 1 shows that the output voltage OUT/FB is monitored against a threshold or reference; Figure 1 also shows that the current going to the output at node LX is monitored for peaks and valleys).
Maxim Integrated does not teach wherein the monitored at least one of an output current or an output voltage of the power stage to determine when to switch to a first mode with the higher voltage and when to switch to a second mode with the lower voltage.
Von Novak teaches a multiple input single inductor power converter (Figure 6A), comprising: at least one switch supply unit (Figure 6A Component 660) comprising a first switch coupled to a first input voltage (Figure 6A Component 660 Middle Switch) that provides a higher voltage value (Figure 6A Component WP PP is the voltage connected with the middle switch; FIG. 7 is an example of an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources; Figure 7 shows that WP PP is set to a voltage value of 5V in the first row); a second switch coupled to a second input voltage (Figure 6A Component 660 Top Switch) that provides a lower voltage value (Figure 7A Component WP coil is the voltage connected with the top switch; Figure 7 shows WP coil is set to a voltage of 2.5 V in the first row which makes it lower than the voltage of Component WP PP); a control unit (Paragraph 0059 “the input switches 660 and the output switches 665 are controlled by a controller (e.g., PMIC 625) implementing a control algorithm configured to enhance efficiency of the power conversion of power conversion circuit 600”) configured to change the input voltage to the lower voltage from the higher voltage (Figure 7 top row shows that when the output voltage required is 1.1V-1.8V WP coil is connected and not WP PP) or the higher voltage to the lower voltage based on the output voltage demand of the load (Figure 7 top row shows that when the output voltage required is 3.3V-5V then WP PP is connected; Paragraphs 0057-0064 highlights that the voltage is selected based on efficiency and the load demands), wherein the controller is configured to monitor the output voltage to determine when to switch to a first mode with the higher voltage and when to switch a second mode with the lower voltage (Paragraph 0064 “an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Maxim Integrated to incorporate a control scheme of selecting a lower voltage source or a higher voltage source based on load conditions as taught by Von Novak. The advantage of this design is that the buck converter can be utilized more efficiently instead of trying to step down a higher voltage in situations where a light load operation is needed thus reducing switching loss and enhancing the efficiency of the overall system.
Regarding claim 8, Maxim Integrated teaches an integrated circuit (IC) (Page 14 Functional Diagram has been annotated as Annotated Figure 1A above for purposes of clarity; Annotated Figure 1A), comprising: a voltage regulator (Annotated Figure 1A Components SC+PS), comprising: a power stage (Annotated Figure 1A Component PS); and a pulse width modulation (PWM) controller configured to have the power stage perform PWM based on an input voltage (Annotated Figure 1A Component SC; Figure 1 on Page 16 shows Component SC in detail which comprises a PWM comparator to generate the control signals; Page 15 Right Column explains that the controller is a PWM based controller); a secondary controller (Annotated Figure 1A Component Power Mux Select Logic) configured to switch (Annotated Figure 1A Components S1 and S2 are selected to be ON and switched) between a first mode where the power stage uses a first input voltage (Annotated Figure 1A Component DC Input 1) to perform PWM (Annotated Figure 1A Component SU changes the input voltage between DC input 1 and DC input 2 based on which switch between Components S1 and S2 is active; Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage highlights that if DC input 1 is higher than DC input 1 and S1 are used) and a second mode where the power stage uses a second, different input voltage (Annotated Figure 1A Component DC input 2) to perform PWM (Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage highlights that if DC input 2 is higher than DC input 2 and S2 are used; DC input 2 is a different input voltage as it comes from a different source).
Maxim Integrated does not teach wherein a singular controller is used for both the converter and the selection of the input voltage source.
Von Novak teaches a multiple input single inductor power converter (Figure 6A), comprising: at least one switch supply unit (Figure 6A Component 660) comprising a first switch coupled to a first input voltage (Figure 6A Component 660 Middle Switch) that provides a higher voltage value (Figure 6A Component WP PP is the voltage connected with the middle switch; FIG. 7 is an example of an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources; Figure 7 shows that WP PP is set to a voltage value of 5V in the first row); a second switch coupled to a second input voltage (Figure 6A Component 660 Top Switch) that provides a lower voltage value (Figure 7A Component WP coil is the voltage connected with the top switch; Figure 7 shows WP coil is set to a voltage of 2.5 V in the first row which makes it lower than the voltage of Component WP PP); a control unit (Paragraph 0059 “the input switches 660 and the output switches 665 are controlled by a controller (e.g., PMIC 625) implementing a control algorithm configured to enhance efficiency of the power conversion of power conversion circuit 600”) configured to change the input voltage to the lower voltage from the higher voltage (Figure 7 top row shows that when the output voltage required is 1.1V-1.8V WP coil is connected and not WP PP) or the higher voltage to the lower voltage based on the output voltage demand of the load (Figure 7 top row shows that when the output voltage required is 3.3V-5V then WP PP is connected; Paragraphs 0057-0064 highlights that the voltage is selected based on efficiency and the load demands).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Maxim Integrated to incorporate a control scheme of selecting a lower voltage source or a higher voltage source based on load conditions as taught by Von Novak. The advantage of this design is that the buck converter can be utilized more efficiently instead of trying to step down a higher voltage in situations where a light load operation is needed thus reducing switching loss and enhancing the efficiency of the overall system.
Regarding claim 9, Maxim Integrated and Von Novak teach all the limitations of claim 8. Maxim Integrated further teaches wherein the power stage comprises a first switch coupled to the first input voltage (Annotated Figure 1A Component S1) and a second switch coupled to the second, different input voltage (Annotated Figure 1A Component S2).
Regarding claim 10, Maxim Integrated and Von Novak teach all the limitations of claim 9. Maxim Integrated further teaches wherein the power stage further comprises: a third switch coupled to both the first and second switches (Annotated Figure 1A Component Q1), wherein the third switch is controlled based on a PWM signal received from the PWM controller to perform PWM using one of the first input voltage or the second, different input voltage (Annotated Figure 1A Component Q1 is controlled by Component Step Down Control which produces a PWM signal to control switches Q1 and Q2; Component Buck uses which ever input voltage is selected).
Regarding claim 11, Maxim Integrated and Von Novak teach all the limitations of claim 8. Maxim Integrated further teaches wherein the PWM controller is configured to monitor at least one of an output current or an output voltage of the power stage to perform PWM (Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage shows that the higher input voltage is used by the buck converter; Annotated Figure 1A Component SC is seen in detail in Figure 1 of Page 16; Figure 1 shows that the output voltage OUT/FB is monitored against a threshold or reference; Figure 1 also shows that the current going to the output at node LX is monitored for peaks and valleys).
Maxim Integrated does not teach wherein the monitored at least one of an output current or an output voltage of the power stage to determines when to switch to the first mode or the second mode.
Von Novak teaches a multiple input single inductor power converter (Figure 6A), comprising: at least one switch supply unit (Figure 6A Component 660) comprising a first switch coupled to a first input voltage (Figure 6A Component 660 Middle Switch) that provides a higher voltage value (Figure 6A Component WP PP is the voltage connected with the middle switch; FIG. 7 is an example of an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources; Figure 7 shows that WP PP is set to a voltage value of 5V in the first row); a second switch coupled to a second input voltage (Figure 6A Component 660 Top Switch) that provides a lower voltage value (Figure 7A Component WP coil is the voltage connected with the top switch; Figure 7 shows WP coil is set to a voltage of 2.5 V in the first row which makes it lower than the voltage of Component WP PP); a control unit (Paragraph 0059 “the input switches 660 and the output switches 665 are controlled by a controller (e.g., PMIC 625) implementing a control algorithm configured to enhance efficiency of the power conversion of power conversion circuit 600”) configured to change the input voltage to the lower voltage from the higher voltage (Figure 7 top row shows that when the output voltage required is 1.1V-1.8V WP coil is connected and not WP PP) or the higher voltage to the lower voltage based on the output voltage demand of the load (Figure 7 top row shows that when the output voltage required is 3.3V-5V then WP PP is connected; Paragraphs 0057-0064 highlights that the voltage is selected based on efficiency and the load demands), wherein the controller is configured to monitor the output voltage to determine when to switch to a first mode with the higher voltage and when to switch a second mode with the lower voltage (Paragraph 0064 “an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Maxim Integrated to incorporate a control scheme of selecting a lower voltage source or a higher voltage source based on load conditions as taught by Von Novak. The advantage of this design is that the buck converter can be utilized more efficiently instead of trying to step down a higher voltage in situations where a light load operation is needed thus reducing switching loss and enhancing the efficiency of the overall system.
Regarding claim 15, Maxim Integrated teaches a method (Page 14 Functional Diagram has been annotated as Annotated Figure 1A above for purposes of clarity; Annotated Figure 1A) comprising: monitoring an output (Annotated Figure 1A Component SC; Figure 1 on Page 16 shows Component SC in detail; Figure 1 shows that OUT/FB voltage parameters are monitored; Figure 1 also shows that Current Valleys and Peaks are also monitored) of a power stage (Annotated Figure 1A Component PS) in a voltage regulator (Annotated Figure 1A Component SC+PS) and comparing them to a threshold (Figure 1 Component OUT/FB is compared with a reference voltage; Component Ilx is compared with a valley reference and a peak reference); in response to a first input voltage being higher, enabling a first mode where the power stage uses a first input voltage (Annotated Figure 1A Component SU changes the input voltage between DC input 1 and DC input 2 based on which switch between Components S1 and S2 is active; Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage shows that the higher input voltage is used as the input voltage for Components Q1 and Q2 which are controlled by a PWM signal) to perform PWM (Figure 1 shows that the controller possesses a PWM signal comparator to generate a PWM signal to control switches Q1 and Q2 based on the input voltage provided); and in response to a second input voltage being higher, enabling a second mode where the power stage uses a second input voltage (Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”; This passage shows that the higher input voltage is used as the input voltage for Components Q1 and Q2 which are controlled by a PWM signal thus if DC input 2 was higher it would be selected) to perform PWM (Figure 1 shows that the controller possesses a PWM signal comparator to generate a PWM signal to control switches Q1 and Q2 based on the input voltage provided).
Maxim Integrated does not teach enabling a first input voltage in response to the output of the power stage falling below a threshold and enabling a second input voltage in response to the output of the power stage being above the threshold.
Von Novak teaches a multiple input single inductor power converter (Figure 6A), comprising: at least one switch supply unit (Figure 6A Component 660) comprising a first switch coupled to a first input voltage (Figure 6A Component 660 Middle Switch) that provides a higher voltage value (Figure 6A Component WP PP is the voltage connected with the middle switch; FIG. 7 is an example of an output of a decision matrix for PMIC 625 where a voltage source (e.g., wireless power (WP) coil, WP post pre-regulator (PP), or Battery) is selected based on the desired output voltage (e.g., 1.1V, 1.8V, 3.3V, 3.6V, or 5V) and the input voltage provided by the different voltage sources; Figure 7 shows that WP PP is set to a voltage value of 5V in the first row); a second switch coupled to a second input voltage (Figure 6A Component 660 Top Switch) that provides a lower voltage value (Figure 7A Component WP coil is the voltage connected with the top switch; Figure 7 shows WP coil is set to a voltage of 2.5 V in the first row which makes it lower than the voltage of Component WP PP); a control unit (Paragraph 0059 “the input switches 660 and the output switches 665 are controlled by a controller (e.g., PMIC 625) implementing a control algorithm configured to enhance efficiency of the power conversion of power conversion circuit 600”) configured to change the input voltage to the lower voltage from the higher voltage (Figure 7 top row shows that when the output voltage required is 1.1V-1.8V WP coil is connected and not WP PP) or the higher voltage to the lower voltage based on load demands or output voltage thresholds (Figure 7 top row shows that when the output voltage required is 3.3V-5V then WP PP is connected; Paragraphs 0057-0064 highlights that the voltage is selected based on efficiency and the load demands; Paragraph 0065 highlights that voltage thresholds can be used; Paragraph 0065 “to select a voltage source that supplies an input voltage slightly below the desired output voltage (e.g., by a first threshold) and boost the voltage than select a voltage source that supplies an input voltage further above the desired output voltage (e.g., by a second threshold) and buck the voltage. F”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Maxim Integrated to incorporate a control scheme of selecting a lower voltage source or a higher voltage source based on load conditions as taught by Von Novak. The advantage of this design is that the buck converter can be utilized more efficiently instead of trying to step down a higher voltage in situations where a light load operation is needed thus reducing switching loss and enhancing the efficiency of the overall system.
Regarding claim 16, Maxim Integrated and Von Novak teach all the limitations of claim 15. Maxim Integrated further teaches wherein monitoring the output of the power stage (Annotated Figure 1A Component SC; Figure 1 on Page 16 shows Component SC in detail) comprises monitoring both an output current (Figure 1 Component ILX is the current going to the output at node LX) and an output voltage (Figure 1 Component OUT/FB is the output voltage feedback) of the power stage to determine whether the output current and the output voltage are below respective thresholds (Figure 1 Component ILX is compared with a peak reference at ILIM and a valley reference at the bottom comparator; OUT/FB is compared with a reference voltage).
Regarding claim 19, Maxim Integrated and Von Novak teach all the limitations of claim 15. Maxim Integrated further teaches wherein enabling the first mode comprises: turning on a first switch to couple the first input voltage (Annotated Figure 1A Component S1) to a second switch that performs PWM (Annotated Figure 1A Component Q1); and turning off a third switch coupled to the second input voltage (Annotated Figure 1A Component S2; Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”).
Regarding claim 20, Maxim Integrated and Von Novak teach all the limitations of claim 19. Maxim Integrated further teaches wherein enabling the second mode comprises: turning on the third switch to couple the second input voltage (Annotated Figure 1A Component S2) to the second switch that performs PWM (Annotated Figure 1A Component Q1); and turning off the first switch coupled to the first input voltage (Annotated Figure 1A Component S1; Page 15 Left Column “The MUX connects the higher of VIN1 or VIN2 to SUP to power the buck. Only the higher voltage input channel is on. The lower voltage input channel is off”).
Allowable Subject Matter
Claims 5, 7, 12 and 14 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 5, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests wherein the first mode is a continuous current mode (CCM), wherein a different duty cycle is used to perform PWM in the first mode than in the second mode. Claim 6 depends upon claim 5, however, is rejected under 35 U.S.C. 112(b) above but would be allowable if the issues raised are overcome through an amendment.
Regarding claim 7, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests wherein the PWM controller is configured to switch to the second mode only after the output current and the output voltage of the power stage have both been below respective thresholds for a predefined time period.
Regarding claim 12, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests wherein the first mode is a CCM, wherein a different duty cycle is used to perform PWM in the first mode than in the second mode. Claim 13 depends upon claim 12, however, is rejected under 35 U.S.C. 112(b) above but would be allowable if the issues raised are overcome through an amendment.
Regarding claim 14, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests wherein the PWM controller is configured to switch to the second mode only after the output current and the output voltage of the power stage have both been below respective thresholds for a predefined time period.
Claims 6, 13 and 17-18 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Regarding claim 6, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests a second power stage, wherein the higher voltage value or a higher current value is used to perform PWM in both the second power stage and the power stage in a 2-phase CCM, wherein the first mode is a 1-phase CCM where the higher voltage value is used to perform PWM in the power stage but not in the second power stage.
Regarding claim 13, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests wherein the voltage regulator further comprises: a second power stage, wherein the first input voltage is used to perform PWM in both the second power stage and the power stage when in a 2-phase CCM, wherein the first mode is a 1-phase CCM where the first input voltage is used to perform PWM in the power stage but not in the second power stage.
Regarding claim 17, none of the prior art, made of record, singularly or in combinations, teaches or fairly suggests wherein the first mode is enabled only when the output current and the output voltage are both below the respective thresholds. Claim 18 depends upon claim 17.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Tang (US 2015/0061619 A1) teaches a switching regulator includes a multiphase converter which includes a plurality of main phases configured to covert a power supply voltage to a lower voltage for application to an electronic device at different load conditions. The switching regulator also includes an auxiliary phase configured to operate in a pulse frequency modulation mode during a light load condition so that power is supplied to the electronic device by at least the auxiliary phase during the light load condition.
Kung (US 2013/0241296 A1) teaches a switching voltage regulator for a power converter is disclosed. The power converter includes a power source selector, a regulator controller, and an inductor. The switching voltage regulator includes: a first power input terminal; a second power input terminal; a first switch having a first terminal coupled with the first power input terminal; a second switch having a first terminal coupled with the second power input terminal; a third switch having a first terminal coupled with a second terminal of the first switch and a second terminal of the second switch; and a fourth switch having a first terminal, coupled with a second terminal of the third switch, for coupling with the inductor. Control terminals of the first switch and the second switch are utilized for coupling with the power source selector. Control terminals of the third switch and the fourth switch are utilized for coupling with the regulator controller.
Khaligh (US 2010/0148587 A1) teaches a multiple-input DC-DC converter that is capable of power diversification among different energy sources with different voltage-current characteristics. The converter is capable of bidirectional operation in buck, boost and buck-boost modes and provides a positive output voltage without the need for a transformer.
Chen (US 11205947 B2) teaches a multi-input single-output DC-DC converter can include: a plurality of input circuits and an output circuit, where each input circuit includes a first switch, and one terminal of each of the input circuits is coupled to an input source, and the other terminal of the input circuit is coupled to the output circuit; and a control circuit configured to control operation periods of each input circuit in one switching period, in order to achieve power distribution and reach requirements for input currents of the input circuit and an output signal of the output circuit.
Potlapalli (US 2024/0297588 A1) teaches a power converter that can operate under low power mode to supply a first load current from a power management integrated circuit (PMIC). The power converter can transition from low power mode to high power mode by one of activating a tri-state mode of the PMIC prior to activating at least one phase in an external power module and operating PMIC and at least one phase of the external power module simultaneously. The external power module and PMIC can be on separate chips. The power converter can operate under high power mode to supply a second load current from the external power module. The second load current can be greater than the first load current. The power converter can transition from high power mode to low power mode by selectively deactivating phases in the external power module prior to activating the PMIC.
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/Shahzeb K Ahmad/Examiner, Art Unit 2838