초록 ▼

A four current transistor temperature sensor comprises a p-n junction, preferably the base-emitter junction of a bipolar transistor, which is driven with four different currents in a predetermined sequence. Each of the four currents induces a respective base-emitter voltage, which is measured. The t

A four current transistor temperature sensor comprises a p-n junction, preferably the base-emitter junction of a bipolar transistor, which is driven with four different currents in a predetermined sequence. Each of the four currents induces a respective base-emitter voltage, which is measured. The temperature of the transistor is calculated based on the values of the four driving currents and the four measured base-emitter voltages. The four driving currents (I1, I2, I3 and I4) are preferably arranged such that I1=2*I3, I2=2*I4, I1/I2=A and I3/I4=A, where A is a predetermined current ratio. I1 and I2 produce respective base-emitter voltages which are subtracted from each other to produce ΔVbe1,and I3 and I4 produce respective base-emitter voltages which are subtracted from each other to produce ΔVbe2. When so arranged, the difference between ΔVbe1and ΔVbe2is entirely due to the effect of series base and emitter resistances rband re. Therefore, the ΔVbe1-ΔVbe2value provides a correction factor which enables temperature measurement errors due to rband reto be eliminated.

대표청구항 ▼

1. A transistor temperature sensing system, comprising: a p-n junction, said p-n junction comprising the base-emitter junction of a bipolar transistor, at least one current source arranged to provide four different currents to said junction in a predetermined sequence, said junction and said at

1. A transistor temperature sensing system, comprising: a p-n junction, said p-n junction comprising the base-emitter junction of a bipolar transistor, at least one current source arranged to provide four different currents to said junction in a predetermined sequence, said junction and said at least one current source arranged such that each of said four currents induces a respective voltage across said junction, and a voltage measurement means connected to measure each of said induced junction voltages, wherein said four different currents are I1, I2, I3 and I4, respectively, and wherein I1=n*I3, I2=n*I4, I1/I2=A and I3/I4=A, where A is a predetermined current ratio. 2. The temperature sensing system of claim 1, wherein said voltage measurement means produces voltage measurements Vbe1-Vbe2and Vbe3-Vbe4when currents I1, I2, I3 and I4 are provided to said transistor in sequence, further comprising a processor arranged to calculate the temperature T of said transistor in accordance with: T=(q*ΔVbe)/[k*ln(I1/I2)]