Systems and methods to perform integrated power measurement and RDSon measurement

摘要

Systems and methods are disclosed to provide a process independent circuit for measuring output current of low drop out (LDO) regulators as well as buck regulators. The system can also measure the on resistance (RDSon) of the buck power transistors.

主权项

1. A power measurement system for a buck regulator, comprising:
a. an output transistor to provide a buck output current of the buck regulator; and b. a sense transistor and sense resistor coupled to the output transistor to sense a portion of the buck output current without degrading the efficiency of the buck regulator, wherein an output voltage is a measure of power output and directly proportional to an output current of the buck regulator and a power output of the buck regulator equals the output current multiplied by the output voltage, wherein a voltage V1 is proportional to a power transistor on resistance RDSon and produces a voltage CS_voltage proportional to RDSon as
RDSon=CS_voltage*(R2/R3)/I1where a test equipment generates a current I1 and R2 and R3 are integrated circuit resistances of matching material and R3 is larger than R2.