Bandgap Reference Circuit and Method for Room Temperature Trimming with Replica Elements

摘要

A method and circuit for trimming a bandgap reference are described. The bandgap reference circuit comprises a first diode which is arranged in series with a first resistor between a reference point and a reference potential VSS. The circuit also comprises a second diode which is arranged in series with a second resistor and a third resistor between the reference point and the reference potential VSS. In addition, the bandgap reference circuit comprises a trimming network, wherein a bandgap reference voltage VBG CORE is provided at a midpoint between the trimming network and the current source. The circuit also comprises an operational amplifier. The method (700) comprises measuring a first diode voltage across a replica element of the first diode; determining a first resistance of a replica element of the first resistor; and setting a resistance of the trimming network using the first diode voltage and the first resistance.

主权项

1) A method for trimming a bandgap reference circuit, wherein the bandgap reference circuit comprises the steps of:
arranging a first diode in series with a first resistor between a reference point and a reference potential; arranging a second diode in series with a second resistor and a third resistor between the reference point and the reference potential; arranging a trimming network in series with a current source between the to reference point and a supply voltage; wherein a bandgap reference voltage is provided at a midpoint between the trimming network and the current source; and coupling a first input of an operational amplifier to a midpoint between the first diode and the first resistor, wherein a second input of the operational amplifier is coupled to a midpoint between the second resistor and the third resistor, and wherein an output of the operational amplifier is used to control the current source; wherein the method further comprises the steps of: measuring a first diode voltage across a replica element of the first diode; determining a first resistance of a replica element of the first resistor; and setting a resistance of the trimming network using the first diode voltage and the first resistance.