Temperature compensation circuit
First Claim
1. A temperature compensation circuit, comprising:
- a plurality of first modules each effective for producing a respective first signal directly proportional to temperaturea plurality of second modules each effective for producing a respective second signal inversely proportional to temperature;
a first summing node for summing all of said first and second signals and producing a resultant summed signal.
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Accused Products
Abstract
A temperature compensation circuit has multiple configurable modules to produce a compensation signal whose temperature characteristic curve is the inverse of the frequency-to-temperature characteristic curve of a specified oscillator. A set of first modules that produce first sub-signals directly proportional to temperature and a set of second modules that produce second sub-signals inversely proportional to temperature have their outputs summed at a summation node. Each module may adjust the strength and shaped of its temperature characteristic sub-signal, and each module may optionally be assigned a temperature offset that impedes the output of its corresponding sub-signal until the assigned temperature offset is reached. Each of the first and second modules includes a signal generator and an optional temperature offset circuit, which may be incorporated into the operation of the signal generator. To produce a compensation signal to compensate a SAW resonator, a first module having a temperature offset and being directly proportional to temperature is summed with a second module having no temperature offset and being inversely proportional to temperature.
27 Citations
67 Claims
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1. A temperature compensation circuit, comprising:
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a plurality of first modules each effective for producing a respective first signal directly proportional to temperature a plurality of second modules each effective for producing a respective second signal inversely proportional to temperature; a first summing node for summing all of said first and second signals and producing a resultant summed signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A temperature compensation circuit, comprising:
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a first temperature dependent signal generator having a first activation temperature, said first temperature dependent signal generator being effective for producing a first signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent signal generator, said second temperature dependent signal generator being effective for producing a second signal inversely proportional to temperature when temperature is not lower than a second activation temperature; a first summing node for summing said first signal and said second signal and outputting the result on a first summation output node; wherein said first temperature dependent signal generator includes; a first signal source for producing a first sub-signal inversely proportional to temperature; a second signal source for producing a second sub-signal directly proportional to temperature; and a second summing node for subtracting the magnitude of said first sub-signal from the magnitude of said second sub-signal; wherein for temperatures lower than a predefined transition temperature the magnitude of said first sub-signal is not less than the magnitude of said second sub-signal, and for temperatures not lower than said predefined transition temperature the magnitude of said first sub-signal is less than the magnitude of said second sub-signal. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A temperature compensation circuit, comprising:
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a first temperature dependent signal generator having a first activation temperature, said first temperature dependent signal generator being effective for producing a first signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent signal generator, said second temperature dependent signal generator being effective for producing a second signal inversely proportional to temperature when temperature is not lower than a second activation temperature; a first summing node for summing said first signal and said second signal and outputting the result on a first summation output node; wherein said first signal and said second signal are voltage signals, and wherein said first summation node is a summing amplifier having a first summing input coupled to receive said first signal and a second summing input coupled to receive said second signal.
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35. A temperature compensation circuit comprising:
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a first temperature dependent signal generator having a first activation temperature, said first temperature dependent signal generator being effective for producing a first signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent signal generator, said second temperature dependent signal generator being effective for producing a second signal inversely proportional to temperature when temperature is not lower than a second activation temperature; a first summing node for summing said first signal and said second signal and outputting the result on a first summation output node; wherein said second temperature dependent signal generator further includes; a third sub-signal source; and a second dependent signal generator for generating a second weighted signal dependent on the output from said third sub-signal source. - View Dependent Claims (36, 37, 38, 39)
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40. A temperature compensation circuit, comprising:
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a first temperature dependent signal generator having a first activation temperature, said first temperature dependent signal generator being effective for producing a first signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent signal generator, said second temperature dependent signal generator being effective for producing a second signal inversely proportional to temperature when temperature is not lower than a second activation temperature; a first summing node for summing said first signal and said second signal and outputting the result on a first summation output node; further comprising; a transimpedance amplifier having an input coupled to said first summation node; a voltage controlled oscillator responsive to said transimpedance amplifier.
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41. A temperature compensation circuit, comprising:
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a first temperature dependent current signal generator having a first activation temperature, said first temperature dependent current signal generator being effective for producing a first current signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent current signal generator, said second temperature dependent signal generator being effective for producing a second current signal inversely proportional to temperature; a first summing node for summing said first current signal and said second current signal and outputting the result on a first summation output node; wherein said first temperature dependent current signal generator includes; a first current source inversely proportional to temperature; and a first current sink directly proportional to temperature; and a second summing node having a first lead coupled to said current source and a second lead coupled to said current sink; wherein for temperatures lower than a predefined transition temperature the magnitude of the output current of said first current source is not less than the magnitude of the sinking current of said current sink, and for temperatures not lower than said predefined transition temperature the magnitude the output current of said current source is less than the magnitude of the sinking current of said current sink. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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55. A temperature compensation circuit, comprising:
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a first temperature dependent current signal generator having a first activation temperature, said first temperature dependent current signal generator being effective for producing a first current signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent current signal generator, said second temperature dependent signal generator being effective for producing a second current signal inversely proportional to temperature; a first summing node for summing said first current signal and said second current signal and outputting the result on a first summation output node; wherein said second temperature dependent signal generator further includes; a sub-signal source; and a second dependent current source for generating a second weighted signal dependent on the output from said sub-signal source. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62, 63, 64)
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65. A temperature compensated oscillator comprising:
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a temperature compensation circuit; and a variable frequency oscillator responsive to the output of said first summation node;
whereinsaid temperature compensation circuit comprises; a first temperature dependent current signal generator having a first activation temperature, said first temperature dependent current signal generator being effective for producing a first current signal proportional to temperature when temperature is not lower than said first activation temperature and for producing substantially no signal when temperature is below said first activation temperature; a second temperature dependent current signal generator, said second temperature dependent signal generator being effective for producing a second current signal inversely proportional to temperature; a first summing node for summing said first current signal and said second current signal and outputting the result on a first summation output node. - View Dependent Claims (66, 67)
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Specification