초록 ▼

An integrated temperature sensor circuit (9) comprises two different current sources (14 and 15) multiplexed using switches (12 and 13) controlled by Clocks 1 and 2 having opposite phases into a bipolar transistor 11. V.sub.be is developed on capacitor (23) during the first clock phase and .DELTA.V.

An integrated temperature sensor circuit (9) comprises two different current sources (14 and 15) multiplexed using switches (12 and 13) controlled by Clocks 1 and 2 having opposite phases into a bipolar transistor 11. V.sub.be is developed on capacitor (23) during the first clock phase and .DELTA.V.sub.be is developed on capacitor (23) during the second clock phase. A second capacitor (27) is coupled between the input and output of an operational amplifier (25). The second capacitor (27) is discharged during the first clock phase and is charged during the second clock phase. Since .DELTA.V.sub.be is dependent on temperature, the voltage at the output of the operational amplifier (25) is dependent on the temperature and the ratio of the two capacitors.

대표청구항 ▼

[ What I claim is:] [1.] An integrated temperature sensor comprising:a first bipolar transistor having a control electrode, a first current electrode coupled to the control electrode and to a reference potential and a second current electrode;a first current source providing a first current and bein

[ What I claim is:] [1.] An integrated temperature sensor comprising:a first bipolar transistor having a control electrode, a first current electrode coupled to the control electrode and to a reference potential and a second current electrode;a first current source providing a first current and being coupled via a first switch to the second current electrode of the first transistor;a second current source providing a second current and being coupled via a second switch to the second current electrode of the first transistor;an amplifier circuit having an input and an output;a coupling capacitor coupled between the second current electrode of the first transistor and the input of the amplifier circuit;a first clock input coupled to the first switch for receiving a first clock signal for switching the first current source to the second current electrode of the first transistor during a first clock phase; anda second clock input coupled to the second switch for receiving a second clock signal for switching the second current source to the second current electrode of the first transistor during a second clock phase which is substantially opposite to the first clock phase;wherein the amplifier circuit produces a signal at its output dependent on the difference in voltage on the coupling capacitor during the two clock phases and hence indicative of the temperature. [13.] A method of sensing temperature comprising the steps of:switching a first current to the emitter of a bipolar transistor during a first clock phase;switching a second current to the emitter of the bipolar transistor during a second clock phase which is substantially opposite to the first clock phase;charging a coupling capacitor during each of the clock phases according to the base-emitter voltage across the transistor caused by the first and second currents;transferring the charge from the coupling capacitor to an amplifier circuit to produce a signal dependent on the difference in base-emitter voltages on the coupling capacitor, and hence dependent on the temperature. A method of sensing temperature according to claim 13, wherein the amplifier circuit comprises an operational amplifier having a second capacitor coupled between an input and an output thereof, and the step of transferring the charge from the coupling capacitor comprises the steps of:shorting the second capacitor during the first clock phase; anddeveloping a voltage on the second capacitor during the second clock phase, such that the output of the operational amplifier during the second clock phase is dependent on the temperature and the ratio of the capacitances of the two capacitors.