Current limit control with constant accuracy

摘要

The present document relates to a current sensing and/or control circuit with reduced sensing errors. A current control circuit for controlling a load current into an electronic device is described. The current control circuit comprises an array of control transistors configured to adjust the load current provided at an output of the array of control transistors. The load current is drawn from a power supply at an input voltage. Furthermore, the power supply is coupled to an input of the array of control transistors. The circuit further comprises a reference transistor coupled to the power supply at an input of the reference transistor and a reference current source configured to draw a reference current at an output of the reference transistor.

主权项

1. A current control circuit for controlling a load current into an electronic device, the current control circuit comprising
an array of control transistors configured to adjust the load current provided at an output of the array of control transistors; wherein the load current is drawn from a power supply at an input voltage; wherein the power supply is coupled to an input of the array of control transistors; a reference transistor coupled to the power supply at an input of the reference transistor; a reference current source configured to draw a reference current at an output of the reference transistor; a controller configured to select one or more control transistors from the array of control transistors; and transistor control units configured to control the reference transistor to provide a reference on-resistance and to control the selected one or more control transistors to provide an array on-resistance; wherein the controller is configured to select the one or more control transistors such that a ratio of a target level of the load current and the reference current corresponds to a ratio of the reference on-resistance and the array on-resistance.