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 .
Response to Arguments
Applicant's arguments filed 06 APR 26 have been fully considered. Applicant’s arguments regarding claim 1 on pages 6-8 of the amendment were persuasive to overcome the previous rejection of claim 1 over Smith. Applicant argued that the current comparator of Smith was voltage-mode current comparator rather than a current-mode current comparator as required by the claims. The argument was found to be persuasive with regard to independent claim 1 but independent claim 8 does recite that the comparator is a current-mode comparator, and thus, this argument was not persuasive to overcome the rejection of independent claim 8. In response, further search was conducted and a new reference was found which teaches that a voltage-mode comparator may be replaced with a current mode comparator. This reference was used to further reject claim 1.
On pages 9 & 10 of the response, it was further argued that Smith does not teach the limitation of independent claims 1 & 8 which recite using a control circuit to turn of the switches in response to receiving the control signal. It is argued that the office action cited element 136 as the control circuit but that 136 simply disables the entire circuit in response to the state of enable/disable pin 140. It is argued that rather than using control circuit 136, circuits 130 & 132 are used to disable the switches when the overcurrent condition is detected. In response, the rejection has been changed to state that the section of the control circuit 120 which disables the switches 110 & 112 in response to the overcurrent being detected maps to the control circuit of the claims. Applicant appears to admit that OV detection circuit 130 and UV detection circuit disables the switches in response to the overcurrent condition. In this case130/132 could be taken to be the control circuits. Either way, column 5, lines 5-23 of Smith teaches that control circuit 120 disables the switches if an overcurrent is detected by sense circuit 134 which clearly teaches the limitation of independent claims 1 & 8. As such this argument was not persuasive to overcome the rejection of claims 1 & 8 over Smith.
Claim Rejections - 35 USC § 102
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 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.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 8, 9 & 14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Smith (US 5,534,788).
With regard to claims 8, 9 & 14, Smith, in Figure 1, discloses a dual-polarity high-current protection circuit (column 5, lines 5-23 teaches that over current protection is provided in both directions thus providing dual polarity protection) comprising: a protection circuit coupled to a to-be-protected current node and an output current node (node coupled to sense resistor 122); a current sensing circuit (134) that, in response to sensing an overcurrent condition present at the output current node, generates an output signal indicative of the overcurrent condition; and a control circuit (section of 120 which deactivates the MOSFETs 110 & 112 when an overcurrent is detected across 122 as taught in column 5, lines 5-23) coupled to the current sensing circuit, the control circuit, in response to receiving the output signal, causes the protection circuit to assume a high impedance to isolate the to-be-protected current node from the overcurrent condition (column 5, lines 5-23) (re claim 8), wherein the overcurrent condition is a current level outside of an operating current range of the to-be-protected current node (column 1, lines 12-16 teaches that the overcurrent condition can damage or compromise the safety of the device which would necessarily have an overcurrent limit that reacts within the operating range to prevent damage) (re claim 9), wherein the current sensing circuit comprises a switch (604 of Fig. 6) coupled to the output current node, the switch generating the output signal in form of a current (re claim 14).
Claim Rejections - 35 USC § 103
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 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.
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 of this title, 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.
Claims 1 & 2 are rejected under 35 U.S.C. 103 as being unpatentable over Smith in view of Huang (US 2018/0248473).
With regard to claims 1, Smith, in Figures 1 & 6, discloses an overcurrent protection method (column 3, lines 5-12) comprising: using a sensing circuit (134) that, in response to an overcurrent condition being present at a current node, detects a current; using a current comparator (column 7, lines 6-26 teaches that sense circuit may comprise a current comparator) to convert the current to a control signal (654); and using a control circuit (section of 120 which deactivates the MOSFETs 110 & 112 when an overcurrent is detected across 122 as taught in column 5, lines 5-23) that, in response to receiving the control signal, turns off a set of switching devices (110 & 112) that are coupled to a to-be-protected current node to create a high-impedance electrical path between the current node and the to-be-protected current node (column 5, lines 5-23).
Smith does not teach that the current comparator is a current mode comparator.
Huang teaches an over current protection circuit (Abstract). It is further taught that protection circuit can comprise a current mode comparator (650). It is also taught that the current-mode comparator can be used in place of a voltage-mode comparator (paragraph 0079).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Smith with Huang, by using a current-mode current comparator instead of a voltage-mode current comparator in the sensing circuit of Smith as taught by Huang, for the purpose of providing a comparator with a quick response time, lower power consumption, and lower input impedance and which does not require placing a resistance in series with the load.
With regard to claim 2, Smith in view of Huang discloses that the overcurrent condition is a current level outside of an operating current range of the to-be-protected current node (Smith, column 1, lines 12-16 teaches that the overcurrent condition can damage or compromise the safety of the device which would necessarily have an overcurrent limit that reacts within the operating range to prevent damage).
Allowable Subject Matter
Claims 3-7, 10-13 & 15-19 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 3 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because the prior art of record does not teach or fairly suggest an overcurrent protection method comprising all the features as recited in the claims and in combination with the sensing circuit being a current sensing circuit and the control signal is a state signal that controls a set of bias currents.
Claims 4-7 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because they depend on claim 3 which would also be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 10 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because the prior art of record does not teach or fairly suggest an overcurrent protection method comprising all the features as recited in the claims and in combination with the protection circuit comprises two sets of switches, each set comprising opposing body diodes.
Claims 11 & 19 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because they depend on claim 10 which would also be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 12 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because the prior art of record does not teach or fairly suggest an overcurrent protection method comprising all the features as recited in the claims and in combination with the operating current range being controlled by an output stage state of an operational amplifier that is coupled to the to-be-protected current node.
Claim 13 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because it depends on claim 12 which would also be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 15 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because the prior art of record does not teach or fairly suggest a circuit comprising all the features as recited in the claims and in combination with an additional current sensing circuit coupled to the current sensing circuit, the additional current sensing circuit, in response to receiving the current, outputs a state signal that controls a set of bias currents.
Claims 16-18 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims because they depend on claim 15 which would also be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 20 is allowable.
Claim 20 is allowable because the prior art of record does not teach or fairly suggest a switch network for bidirectional high-current protection of a current node comprising all the features as recited in the claims and in combination with generating a low-level signal to control bias currents to cause the two sets of switches to turn on, such that a current flowing between the to-be-protected current node and the output current node is determined by on-resistances of the two sets of switches and a load voltage present at the output current node; and in response to the current at the output current node falling outside the current range, a drain current exceeding a current value causing a corresponding comparator in the set of comparators generating a high-level signal that causes the bias currents and, thus, the two sets of switches to turn off, thereby, creating a high-impedance path between the to-be-protected current node and the output current node, the current at the to-be-protected current node being controlled by an output stage state of an operational amplifier to be within the current range, the current at the output current node assuming values between a lower current threshold and a higher current threshold.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SCOTT BAUER whose telephone number is (571)272-5986. The examiner can normally be reached M-F 12pm - 8pm EST.
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/Scott Bauer/ Primary Examiner, Art Unit 2838
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