Bandgap voltage reference circuit and method with low TCR resistor in parallel with high TCR and in series with low TCR portions of tail resistor

A bandgap voltage reference circuit, comprising:

• a pair of transistors having respective bases, collectors and emitters,
• an output voltage terminal connected to the bases of said transistors,
• means for establishing unequal emitter current densities in said transistors,
• a first resistor having a relatively low temperature coefficient of resistance (TCR) connected between the emitters of said transistors,
• second and third resistors having respective relatively low and relatively high TCRs connected in series between the emitter of one of said transistors and a voltage reference, and
• a fourth resistor having a relatively low TCR connected in parallel with said third resistor, the TCRs of said third and fourth resistors and the ratio between their resistance values being selected to substantially compensate for a Tln(T) deviation from linearity in the voltage at said output terminal that is present in the absence of said third and fourth resistors, where T is absolute temperature.

A bandgap voltage reference circuit, comprising:

• a pair of transistors having respective bases, collectors and emitters,
• an output voltage terminal connected to the bases of said transistors,
• means for providing collector currents to said transistors,
• a first resistor having a relatively low temperature coefficient of resistance (TCR) connected between the emitters of said transistors,
• second and third resistors having respective relatively low and relatively high TCRs connected in series between the emitter of one of said transistors and a voltage reference, and
• a fourth resistor having a relatively low TCR connected in parallel with said third resistor, said parallel resistors substantially cancelling temperature dependent deviations in the voltage at said output terminal over a desired temperature range.

A bandgap voltage reference circuit, comprising:

• a pair of transistors having respective bases, collectors and emitters,
• an output voltage terminal connected to the bases of said transistors,
• means for providing collector currents to said transistors,
• a first resistor having a relatively low temperature coefficient of resistance (TCR) connected between the emitters of said transistors,
• a second resistor having a relatively low TCR, and
• a correction circuit connected in series with said second resistor between the emitter of one of said transistors and a voltage reference, said correction circuit having a non-linear resistance-temperature characteristic selected to substantially cancel temperature dependent deviations in the voltage at said output terminal over a desired temperature range.