Method and circuit for trimming a current source in a package

Abstract

A method and circuit for trimming a current source packaged with a device can facilitate trimming of the current source without the need for additional pins or dual function pins, resulting in improved accuracy and/or simplified trimming techniques. An exemplary packaged device is configured with a trimming circuit comprising a current trimming network and a coupling circuit. An exemplary packaged device can comprise any op amp, current or voltage reference, and/or sensor device, and is configured with one or more monitor inputs. An exemplary current trimming network comprises a variable current source and a reference current source, wherein a magnitude of the variable current source can be compared to the magnitude of the reference current source. An exemplary coupling circuit is coupled between the current trimming network and the device and is configured for enabling and disabling connection of an output of the current trimming network and a monitor input of the device. During an exemplary trimming method, the variable current source is configured with a magnitude adjusted to a desired proportion of a magnitude of the reference current source, with the current trimming network configured to produce a current proportional to the difference, sum, or product of the first and second current sources.