公开(公告)号：US11038426B2

公开(公告)日：2021-06-15

申请号：US16575758

申请日：2019-09-19

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Chin-Hong Cheah

IPC: H02M3/158

Abstract: Circuits and methods for operating a programmable load circuit that includes a plurality of sub-circuits connected in parallel between an input and an output. Each sub-circuit may include an inductor, a load, and a switch coupled to the inductor. Each switch may be configurable in a first state and a second state, wherein the inductor is either connected to the output through the load or connected to the output through a connection that bypasses the load. The switches of the plurality of first sub-circuits may be programmable to periodically switch between the first state and the second state according to a duty cycle, and the switches may be out of phase with each other by a predetermined amount. The duty cycle may be programmable to tune the load of the programmable load circuit.

公开(公告)号：US20210091744A1

公开(公告)日：2021-03-25

申请号：US16575850

申请日：2019-09-19

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Chin-Hong Cheah

IPC: H03H7/40 ,  H01F21/02

Abstract: Circuits and methods for electronically adjusting an effective inductance of one or more primary inductors in a circuit. The circuit may include a plurality of sub-circuits connected in parallel between an input and an output of the circuit. Each sub-circuit may include a primary inductor and an auxiliary inductor inductively coupled to the primary inductor. The circuit may further include first circuitry coupled to the primary inductor, wherein the first circuitry configured to introduce an oscillating first voltage across the primary inductor; and second circuitry coupled to the auxiliary inductor, wherein the second circuitry is configured to introduce an oscillating second voltage across the auxiliary inductor. The amplitudes of the second voltages may be selected to reduce a difference between effective inductances of the primary inductors.