DETAILED ACTION
Claims 1 – 12 are pending in the present application.
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 .
Priority
Receipt is acknowledged of certified copies of papers submitted under 35 U.S.C. 119(a)-(d), which papers have been placed of record in the file.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-12 are rejected under 35 U.S.C. 103 as being unpatentable over Blom et al. (US 20070195856; hereinafter Blom) in view of Perrott et al. (US 10175119; hereinafter Perrott).
Regarding claim 1, Blom teaches a temperature sensor (abstract) comprising:
a first oscillator (“reference oscillator” abstract; [0023]) and a second oscillator (“data oscillator” abstract; [0023]); and
a counter (see at least data counter 60; reference counter 70 and circuit 80; see fig. 1; [0038-40]) configured to count a number of periods of the second oscillator over a duration determined by a period of the first oscillator (“conversion period” [0038] defined by Nc; “The reference frequency Fref defines the conversion period where a fixed number of clock periods, Nc, of the reference frequency indicates the conversion period” [0036]; [0039] teaches that the data is then counted with respect to the reference generated conversion period),
wherein:
one of the first and second oscillators is configured so that its frequency linearly depends on temperature or on the inverse of temperature according to a multiple coefficient of the inverse of a resistance value of a resistive component of said one of the first and second oscillators (abstract; [0023] teaches that at least the data oscillator implements linearity; [0081] teaches plural coefficients for providing linearity; see also [0031]; see also [0003] teaching that plural coefficients are considered for and affect linearity); and
a control frequency is determined by the frequency of the other one of the first and second oscillators (“control signal dswitch2” [0113]; see [0112-113] teaches that the control signal is produced by the I/F converter; please note “current-to-frequency (I/F) converters” are for “implementing the reference oscillator and the data oscillator” [0025]).
Blom does not directly and specifically state regarding said resistive component is implemented by a switched capacitive element; and that the control frequency is of the switched capacitive element.
However, Perrott teaches a temperature sensor (abstract; title) having switch capacitor elements with resistance and a control frequency (see most clearly fig. 9A, Rcap of C2; see also abstract and col. 1, ¶ at 32 “(i) a switched capacitor network that provides or creates a low noise adaptable reference resistor” and “(ii) a frequency divider that is controlled by a digital Sigma-Delta modulator to achieve an accurately controlled switching frequency for the switched capacitor network”).
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the temperature sensor of Blom with the switched capacitor resistance controlled by a switching frequency of Perrott. This is because switched capacitor temperature sensing allows for providing a low noise adaptable reference resistor (col. 6, ¶ at 37 of Perrott). This is important in order to increase accuracy of the temperature sensing by reducing noise in the measurement.
Regarding claim 2, Blom teaches that said one of the first and second oscillators comprises: an oscillating circuit; and a current source configured to deliver a bias current to the oscillating circuit, the current source being of the type proportional to absolute temperature or of the type complementary to absolute temperature (see fig. 1 showing at last 22/24; IPTAT/ICTAT used as biasing current(s); see abstract, [0034] and [0023]).
Regarding claim 3, Blom teaches that the current source comprises the resistive component; the resistive component is configured to convert a voltage into a first current; and the current source is configured so that the bias current is a copy of the first current to within a multiplication factor (at least resistor Rp; see [0034] “A PTAT current can be generated from the .DELTA.Vbe voltage by imposing the .DELTA.Vbe voltage across a resistor (such as resistor Rp)” and similar for ICTAT; see also [0057] “IPTAT is coupled to a buffer 102 where a current multiplication factor Knp is applied to the PTAT current”; see further [0059] regarding duplicate current).
Regarding claim 4, Blom lacks teaching that the oscillating circuit is a ring oscillator.
However, Perrott does disclose using ring oscillators (see at least col. 12, ¶ at 55 and col. 15 ¶ at 16 each teaching regarding using ring oscillators as the oscillator(s)).
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the temperature sensor of Blom with the ring oscillators of Perrott. This is because ring oscillators allow for feeding the oscillations from a known oscillating source or sources into the counter for determining the temperature. This is important in order to provide a known structure for the oscillation production.
Regarding claim 5, Blom and Perrott lack direct and specific teaching that the oscillating circuit is a relaxation oscillator comprising an RS flip-flop.
However, Perrott does disclose using latches with edge triggering (see at least figs. 22 and 23; col. 17, ¶ at 7 and ¶ at 15).
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to further modify the temperature sensor of Blom with the edge triggering latches of Perrott with a desired edge triggering structure such as an RS flip-flop for implementing the circuit. This is because one of ordinary skill in the art would have expected RS flip-flops to be one of several straightforward ways of forming the circuit with an edge trigger because RS flip-flops are known to be closely related to edge triggered latches and are know to produce edge triggers outputs for desired designs.
Regarding claim 6, Blom teaches that the oscillating circuit comprises the resistive component (see at least [0059] teaching at least regarding resistor Rdata).
Regarding claim 7, Blom lacks teaching that said oscillating circuit comprises at least one first inverter having its threshold voltage determining the frequency of said one of the first and second oscillators; and said one of the first and second oscillators further comprises: a second inverter identical to the first oscillator and having its output connected to its input, an error amplifier configured to deliver a signal indicating a deviation between an output voltage of the second inverter and a reference threshold voltage, and a circuit configured to control a threshold voltage of the first and second inverters based on the signal delivered by the error amplifier so that the threshold voltage of the first and second inverters is equal to the reference voltage.
However, Perrott does disclose using ring oscillators with inverters (see at least col. 12, ¶ at 55 and col. 15 ¶ at 16 each teaching regarding using ring oscillators as the oscillator(s); see fig. 20 showing chains of delay buffers and inverters in quantizers; see also fig. 23) operating at a frequency (at least signal clk24(t); col. 16, ¶ at 10) and controlled by voltage (as “voltage-controlled ring oscillators (VCO)” col. 12, ¶ at 14; see col. 15 ¶ at 16).
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the temperature sensor of Blom with the ring oscillators having inverters of Perrott. This is because ring oscillators allow for feeding the oscillations from a known oscillating source or sources into the counter for determining the temperature. This is important in order to provide a known structure for the oscillation production.
Regarding claim 8, Blom lacks direct and specific teaching the sensor comprises a calibration circuit configured to: receive from the counter the number P of periods of the second oscillator counted over the duration determined by the period of the first oscillator; determine, when the calibration circuit receives a calibration request, and based on a known calibration temperature and on number P, a constant coefficient J such that: a) P is equal to J times the calibration temperature if said one of the first and second oscillators is the first oscillator and has its frequency linearly depending on the inverse of temperature or if said one of the first and second oscillators is the second oscillator and has its frequency linearly depending on temperature; or b) P is equal to J times the inverse of temperature if said one of the first and second oscillators is the second oscillator and has its frequency linearly depending on the inverse of temperature or if said one of the first and second oscillators is the first oscillator and has its frequency linearly depending on temperature.
However, Blom does disclose correcting the temperature output signal for linearity (abstract; [0023] teaches that at least the data oscillator implements linearity; [0081] teaches plural coefficients for providing linearity; see also [0031]; see also [0003] teaching that plural coefficients are considered for and affect linearity) using multiples of clock periods for counting digitized PTAT and CTAT currents (see fig. 1; [0034]) during comparison to a reference in a period (“conversion period” [0038] defined by Nc; “The reference frequency Fref defines the conversion period where a fixed number of clock periods, Nc, of the reference frequency indicates the conversion period” [0036]; [0039] teaches that the data is then counted with respect to the reference generated conversion period) and using coefficients in the correction (abstract; [0023] teaches that at least the data oscillator implements linearity; [0081] teaches plural coefficients for providing linearity; see also [0031]; see also [0003] teaching that plural coefficients are considered for and affect linearity) of “ a current proportional to absolute temperature IPTAT on a node 22 and a current complementary to absolute temperature ICTAT on a node 24 in response to temperature stimuli” ([0034]).
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the reference-based linearity correction for a PTAT and/or CTAT temperature signal of Blom and Perrott with specific calibration of the signals which are being corrected. This is because one of ordinary skill in the art would have expected calibrating to be one of several straightforward ways of correcting the signals because calibration is well known in the art as a form of correcting signals in this manner.
Regarding claim 9, Blom teaches that the sensor comprises a calculation circuit configured to determine a temperature value based on said counted number (abstract; see also [0040] “the digital temperature output signal and can be processed to provide a temperature output signal”; see also [0038-40]).
Regarding claim 10, Blom and Perrott lack direct and specific teaching that the sensor is configured so that the duration determined by the frequency of the first oscillator is at least 100 times greater than a period of the second oscillator.
However, Perrott does disclose having a ten-time multiplier (Col. 16, ¶ at 47 “to switch the capacitor network at 48 MHz, it's straightforward to see that this may be obtained by dividing the 480 MHz clock by 10”; see fig. 21).
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the ten-time multiple for switching of the reference vs the measurement of Perrott with any particularly desired multiplier including 100X. This is because one of ordinary skill in the art would have expected setting the oscillator frequency ratio to be one of several straightforward ways of increasing the resolution/response time of the sensor because it has been held that discovering an optimum value of a result effective variable (here the relative frequencies) involves only routine skill in the art. MPEP 2144.05 (II-B).
Regarding claim 11, Blom lacks teaching that the sensor is configured so that the control frequency of the switched capacitive element is at least 10 times greater than the frequency of said one of the first and second oscillators.
However, Perrott does disclose having a ten-time multiplier (Col. 16, ¶ at 47 “to switch the capacitor network at 48 MHz, it's straightforward to see that this may be obtained by dividing the 480 MHz clock by 10”; see fig. 21)
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the temperature sensor of Blom with the switched capacitor resistance controlled by a switching frequency with a 10X greater frequency between oscillators of Perrott. This is because switched capacitor temperature sensing allows for providing a low noise adaptable reference resistor (col. 6, ¶ at 37 of Perrott). This is important in order to increase accuracy of the temperature sensing by reducing noise in the measurement.
Regarding claim 12, Blom teaches that each of the first and second oscillators comprises no quartz (see at least [0045] teaching that the oscillators have a capacitor, a comparator and switching circuits).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See PTO-892.
See especially:
Gold et al. (US 20030156622); abstract and figs. 2-5.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PHILIP COTEY whose telephone number is (571)270-1029. The examiner can normally be reached M-F 9-5.
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/PHILIP L COTEY/ Examiner, Art Unit 2855
/LAURA MARTIN/ SPE, Art Unit 2855