Microchip Technology Inc.

James E Bartling

Stephen Bowling

Bryan Kris

Igor Wojewoda

Darren Edward Noel Wenn

Ajay Kumar

Kevin L Kilzer

D C Sessions

Raghuveer Murukumpet

Jinhui Chen

David Otten

Jason Tollefson

Aaron Joel Mach

Dennis P Lehman

Bruce Bohn

Neil Deutscher

A Proportional-To-Absolute-Temperature (PTAT) current source is used for high-resolution temperature measurement. The PTAT current source is coupled to a capacitor for a fixed amount of time so as to charge the capacitor to a voltage which is proportional to the current applied to the capacitor, and thus proportional to the temperature. The voltage on the capacitor is measured, and a temperature is calculated or determined from the measured voltage.

Current-based temperature measurement devices and methods

An apparatus includes a capacitor, a reference voltage, an input signal to be measured, and a frequency calculation circuit. The frequency calculation circuit is configured to select a capacitance value for the capacitor, charge the capacitor with the reference voltage, discharge the capacitor to a threshold voltage, and, based on a comparison of time to discharge the capacitor to the threshold voltage with a clock cycle of the input signal, determine a frequency of the input signal.

Fast frequency calculator

A voltage regulator includes an error amplifier configured to amplify a difference between a feedback voltage and a reference voltage. The regulator also includes an N-type metal-oxide-semiconductor (NMOS) driver circuit. The driver circuit includes an n-type field effect transistor. The driver circuit is communicatively coupled to output of the error amplifier. The regulator further includes a feedback circuit communicatively coupled between the NMOS driver circuit and an input of the error amplifier to provide the feedback voltage.

On chip NMOS gapless LDO for high speed microcontrollers

A constant current source, a stable time base and a capacitor are used to self-check operation of an analog-to-digital convertor (ADC) by charging the capacitor for a pre-determined amount of time to produce a voltage thereon. This voltage will be proportional to the amount of time that the capacitor was charged. Multiple points on the ADC transfer function can be verified in this self-check procedure simply by varying the amount of time for charging of the capacitor. Relative accuracy among test points may then be easily obtained. Absolute accuracy may be obtained by using an accurate clock reference for the time base, a known current source and capacitor value.

ADC self-test using time base and current source

An integrated circuit amplifier configurable to be either a programmable gain amplifier or an operational amplifier comprises two output blocks, one output block is optimized for programmable gain amplifier operation, and the other output block is optimized for operational amplifier applications. A common single input stage, input offset calibration and bias generation circuits are used with either amplifier configuration. Thus duplication of the input stage, offset calibration and bias generation circuits are eliminated while still selectably providing for either a programmable gain amplifier or operational amplifier configuration.

Selectable programmable gain or operational amplifier

The average of a complex waveform measured over a time period may be determined by first converting the complex waveform to a voltage, then converting this voltage to a current and using this current to charge a capacitor. At the end of the measurement time period the voltage charge (sample voltage) on the capacitor may be sampled by a sample and hold circuit associated with an analog-to-digital converter (ADC). Then the voltage charge on the sample capacitor may be removed, e.g., capacitor plates shorted by a dump switch in preparation for the next average of the complex waveform sample measurement cycle. The ADC then converts this sampled voltage charge to a digital representation thereof and a true average of the complex waveform may be determined, e.g., calculated therefrom in combination with the measurement time period.

Microcontroller with average current measurement circuit using voltage-to-current converters

A micro-coded sequencer controls complex conversion sequences independent of a central processing unit (CPU). Micro-coding provides for easily adding new process steps and/or updating existing process steps. Such a programmable sequencer in combination with an analog-to-digital conversion module such as an analog-to-digital converter (ADC) or a charge time measurement unit (CTMU), and digital processing circuits may be configured to work independently of the CPU in combination with the micro-coded sequencer. Thereby providing self-sufficient operation in low power modes when the CPU and other high power modules are in a low power sleep mode. Such a peripheral can execute data collection and processing thereof, then wake the CPU only when needed, thereby saving power. Furthermore, this peripheral does not require CPU processing so that time critical applications that do require control by the CPU can operate more efficiently and with less operating overhead burden.

Analog-to-digital conversion with micro-coded sequencer

A microcontroller has an input capture peripheral, wherein the input capture peripheral is configured to store timer values of an associated timer in a memory and wherein the input capture peripheral has a gating input which controls whether an input capture function is activated.

Input capture peripheral with gating logic

A microcontroller has a programmable timebase, wherein the timebase has a trigger input to start a timer or counter of the timebase and wherein the timebase can be configured to operate upon receiving a trigger signal in a first mode to generate a plurality of timer/counter event signals until a reset bit in a control register is set and in a second mode to generate a single timer/counter event signal and wherein the timebase can be configured to operate in a third mode to generate a predefined number of timer/counter event signals, wherein the predefined number is defined by a plurality of bits of a register.

Timebase peripheral

A blood glucose meter comprises a blood sample test strip, a constant current source, a precision timer, a digital processor and memory, and an analog measurement circuit, e.g., voltage comparator, analog-to-digital converter (ADC), etc., that eliminates the complex analog front end and other related circuits of present technology glucose meters. When a blood sample is applied to the blood sample test strip a charge, Q, develops from the reaction between an enzyme in the test strip and the blood sample. The constant current source injects a constant current value, I, into the charge, Q, on the blood sample test strip over a precisely measured time determined by when the excess charge, Q, has been removed from the test strip. The amount of charge, Q, is determined by Q=I*T, the charge, Q, is then converted into a blood glucose level for display.

Glucose measurement using a current source

Temperature is determined by measuring the time it takes to charge a capacitor with a resistive temperature sensor. A clock, time counter, a voltage comparator and voltage reference are used in determining a coarse time measurement. The time measurement resolution is enhanced with the addition of a constant current source charging another timing capacitor within a single clock pulse time to provide a fine time measurement.

High resolution temperature measurement

A fluorescent lamp light intensity dimming control generates a pulse width modulation (PWM) signal at about a fifty percent duty cycle and has very fine frequency change granularity to allow precise and smooth light dimming capabilities. Intermediate PWM signal frequencies between the frequencies that are normally generated from values in a period register of the PWM generator are provided with a variable frequency clock source to the PWM generator. Selection of each frequency from the plurality of frequencies available from the variable frequency clock source may be determined from a value stored in a variable frequency clock register. A microcontroller may be used to select appropriate frequencies for dimming control of the fluorescent lamp from the variable frequency clock source, and the period and duty cycle values used in generating the PWM signal at about a fifty percent duty cycle.

High resolution pulse width modulation (PWM) frequency control using a tunable oscillator

A scan module of an electronic device scans a capacitive keypad for detection of the actuation of any capacitive touch sensor. This scan module remains in operation even when major power consuming circuits of the electronic device are in a sleep mode, and will not wake up the major power consuming circuits until an action requiring the circuits is needed, thereby, reducing overall power consumption of the electronic device while still maintaining scanning of the capacitive keypad. Upon detection of a valid key press of a capacitive touch sensor, an interrupt to the electronic device brings it out of a sleep mode and into an operating mode for further processing and appropriate action commensurate with the actuation of the specific capacitive touch sensor.

Automated capacitive touch scan

A time period of an event is determined by charging a known value capacitor from a constant current source during the event. The resultant voltage on the capacitor is proportional to the event time period and may be calculated from the resultant voltage and known capacitance value. Capacitance is measured by charging a capacitor from a constant current source during a known time period. The resultant voltage on the capacitor is proportional to the capacitance thereof and may be calculated from the resultant voltage and known time period. A long time period event may be measured by charging a first capacitor at the start of the event and a second capacitor at the end of the event, while counting clock times therebetween. Delay of an event is done by charging voltages on first and second capacitors at beginning and end of event, while comparing voltages thereon with a reference voltage.

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Chandler, AZ, United States of America

James E Bartling