Microcontroller with on-chip linear temperature sensor
First Claim
1. A microcontroller device for use in battery charging and battery monitoring applications, the device having a microcontroller fabricated on a semiconductor chip to execute programs and instructions and to generate control signals as a result of execution by the microcontroller of programs and instructions for selectively controlling a battery charging and battery monitoring system when said chip is housed in a battery pack with the battery to be charged and monitored, the microcontroller including microprocessor means for executing instructions, program memory means for storing programs to be executed by the microcontroller and data memory means for storing data, the device further including:
- on-chip, temperature sensor means fabricated on the same chip with said microcontroller for monitoring the temperature of the chip, said on-chip, temperature sensor means including;
voltage means for generating a first voltage having a level linearly proportional to absolute temperature of the chip; and
means for sampling said first voltage and for developing a digital count representative of the level of said first voltage as a measure of the absolute temperature of the chip and of the battery with which the chip is housed and indicative of the then-current energy capacity of the battery.
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Accused Products
Abstract
A microcontroller for use in battery charging and monitoring applications is disclosed. The microcontroller includes a microprocessor and various front-end analog circuitry including a slope A/D converter and a multiplexer for allowing a plurality of analog input signals to be converted to corresponding digital counts indicative of signal level. The microcontroller further includes an on-chip temperature sensor, used in conjunction with the A/D converter, to monitor the temperature of the microcontroller. The temperature sensor generates and uses a differential voltage that is obtained across the base-emitter functions of two compatible bipolar transistors having dissimilar emitter areas. This differential voltage is proportional to temperature and may be sampled by the A/D converter to obtain a digital count indicative of the temperature of the microcontroller.
134 Citations
10 Claims
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1. A microcontroller device for use in battery charging and battery monitoring applications, the device having a microcontroller fabricated on a semiconductor chip to execute programs and instructions and to generate control signals as a result of execution by the microcontroller of programs and instructions for selectively controlling a battery charging and battery monitoring system when said chip is housed in a battery pack with the battery to be charged and monitored, the microcontroller including microprocessor means for executing instructions, program memory means for storing programs to be executed by the microcontroller and data memory means for storing data, the device further including:
on-chip, temperature sensor means fabricated on the same chip with said microcontroller for monitoring the temperature of the chip, said on-chip, temperature sensor means including; voltage means for generating a first voltage having a level linearly proportional to absolute temperature of the chip; and means for sampling said first voltage and for developing a digital count representative of the level of said first voltage as a measure of the absolute temperature of the chip and of the battery with which the chip is housed and indicative of the then-current energy capacity of the battery. - View Dependent Claims (2, 3, 4)
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5. A device-implemented method for obtaining a measurement of the absolute temperature of a semiconductor device on a chip in which a microcontroller is fabricated to execute programs and instructions and to generate control signals as a result of execution by the microcontroller of programs and instructions for selectively controlling the current charging and discharging rate of an external battery with which the chip is housed, the microcontroller including microprocessor means for executing instructions, program memory means for storing programs to be executed by the microcontroller and data memory means for storing data, the device-implemented method comprising the steps of:
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generating a signal having a voltage level proportional to absolute temperature of the chip from an on-chip temperature sensor; and sampling said signal with analog-to-digital converter means to obtain a digital count indicative of the voltage level of said signal as a measure of absolute temperature of the chip and of the battery with which the chip is housed, as an indication of the current energy capacity of the battery. - View Dependent Claims (6)
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7. A battery-monitoring semiconductor device fabricated within a single semiconductor chip for use as a fuel gauge indicative of battery energy capacity and battery charging and discharging rates when the device is housed in an external battery pack with a battery to be monitored, the device comprising:
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a microcontroller including a central processing unit (CPU); an on-chip temperature sensor coupled to the microcontroller for monitoring the temperature of the chip as a measure of the temperature of said battery, said sensor including; a pair of transistors each having different electrode areas from the other in a respective current path therethrough, means for detecting a voltage difference between said transistors attributable to the different electrode areas, wherein said voltage difference is linearly proportional to the temperature of said chip, and means for measuring said voltage difference as a measure of the temperature of the chip and of the battery with which it is housed; and means coupled to said microcontroller for sensing a voltage having a magnitude representative of current flow through the battery and for adjusting said current flow according to a programmed level of a variable voltage source, to control the rate of charging or discharging of the battery. - View Dependent Claims (8, 9, 10)
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Specification