US 12,689,283 B2 · CMOS integration of a high bandwidth optically isolated current sensor

Abstract

A galvanically isolated current sensor for power converters is disclosed. The sensor includes a package housing a first integrated circuit (IC), a light emitting layer, an optical waveguide, a photosensing layer, and a second IC. The light emitting layer emits light proportional to a reference current. The optical waveguide modulates the light based on a magnetic field generated by the current to be sensed. The photosensing layer generates a photocurrent representative of the modulated light's intensity. The second IC outputs a sense current based on the photocurrent. The optical waveguide includes polarizers and a Faraday rotator material to effectuate the modulation. Different embodiments of control circuitry for processing the sense current are described, including a flash ADC-based system, a voltage-controlled oscillator with a high-speed counter, and a current-controlled delay line with a low-speed counter.

Claims18

Dependent claims

A power converter, comprising:

circuitry;
a metal trace through which a current output by the circuitry flows;
a current sensor configured to measure the current, the current sensor comprising:
a package having disposed therein:
a first integrated circuit (IC);
a light emitting layer operatively coupled to the first IC and configured to emit light having an intensity proportional to a reference current received by the first IC;
an optical waveguide having an input receiving the light emitted by the light emitting layer and having an output, wherein the optical waveguide is configured to modulate the light passing therethrough based on a magnetic field generated by the current in the metal trace;
a photosensing layer configured to generate a photocurrent representative of the intensity of the light output from the optical waveguide;
and
a second integrated circuit (IC) operatively coupled to the photosensing layer and configured to output a sense current based upon the photocurrent, with the sense current being representative of the current in the metal trace.

7 more elements

Dependencies are inferred from the claim text.

CMOS integration of a high bandwidth optically isolated current sensor

Life of this patent

CMOS integration of a high bandwidth optically isolated current sensor

Life of this patent

Abstract

Claims18