Microcontroller with improved A/D conversion
AssigneeMicrochip Technology Incorporated
InventorsSumit Mitra, Russ Cooper, Martin Burghardt
Life of this patent
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Abstract
A semiconductor microcontroller includes the capability to perform analog to digital conversions of an analog signal representative of a variable parameter indicative of the need to exercise a control function. While the analog to digital conversions are being performed, the microcontroller processor can be powered down to eliminate noise arising from switching activities of the processor as a source of inaccuracy in the conversion process. At the end of the conversion, the analog to digital converter can either shut itself down or wake up the processor. The powering down is achieved by simply disabling the clock input to the microcontroller so that the processor is still activated but incapable of undergoing switching functions.
Claims17
A microcontroller device for performing control functions on a system to be controlled, comprising:
- control means for performing the control functions,
- analog to digital conversion means for performing conversions to assess a condition affecting the controlled system for use by the control means in determining whether a control function is to be performed, and
- error reduction means for reducing conversion error attributable to noise perturbations from the control means by deactivating the control means while the analog to digital conversion means is performing conversions.
In a CMOS microcontroller adapted to perform analog to digital conversions of an analog signal representative of a variable parameter indicative of whether or not a control function is to be exercised by the microcontroller, and including a source of power, the improvement comprising:
- an analog to digital converter for perforating the conversions, and
- control logic means responsive to the analog to digital converter performing a conversion, for powering down the microcontroller for a period required to perform the conversion to reduce conversion error attributable to performance of switching functions by the microcontroller.
A method of operating a microcontroller device to perform control functions on a system to be controlled, comprising the device-implemented steps of:
- performing analog to digital conversions to assess a condition affecting the controlled system to determine whether a control function is to be performed on the controlled system by the microcontroller device, and
- deactivating a portion of the microcontroller device while performing each analog to digital conversion, to reduce conversion error attributable to noise which would otherwise be generated by power consuming switching functions of said portion of the microcontroller device.
A method of operating a CMOS device adapted to perform analog to digital conversions and having intelligent control logic, comprising the device-implemented steps of:
- performing analog to digital conversions of a predetermined analog input signal as part of the device operation, and
- during each analog to digital conversion, deactivating designated portions of the device engaged in switching functions other than for performing an analog to digital conversion, to reduce conversion error otherwise attributable to switching functions performed by the portions designated for deactivation.
Dependencies are inferred from the claim text.