Signal isolation device

Abstract

To provide an electronic device that receives an input signal and in response generates an isolated drive signal to a solid-state switch that transitions from an off state to an on state.SOLUTION: A signal isolation device 100 comprises: a transmit die 120 including transmitter output terminals 125, transmit circuitry 205, and input terminals 105; and a receiver die 140 including receiver input terminals 135, output terminals 110, and a coupler 115. The transmit die 120 is attached to a top surface of the receiver die 140. The coupler includes: a transmit coil 240 connected to the transmitter output terminals 125; a receiver coil 235 positioned proximate to the transmit coil 240 and connected to the output terminals 110; receiver circuitry 215; and a shield layer 225 positioned between the receiver circuitry 215 and the receiver coil 235.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 549,663, entitled "SIGNAL ISOLATOR WITH INTEGRAL ELECTROMAGNETIC SHIELD," filed February 5, 2024, the entire contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] The described embodiments relate generally to electronic devices that isolate input signals from output signals, and more particularly to electronic devices that receive an input signal and, in response, generate an isolated drive signal to a solid-state switch that transitions from an off state to an on state. [Background technology]

[0003] A wide variety of electronic devices currently exist that isolate input signals from output signals. Current electronic devices have limited operating voltages and relatively low coupling coefficients. Furthermore, many current electronic devices are relatively large and / or require the interconnection of separate, discontinuous components.

[0004] A need exists for a signal isolator device that is integrated, compact, and operates at relatively high voltages with a relatively high coupling coefficient. Summary of the Invention

[0005] In some embodiments, the signal isolation device includes a transmitter die including a pair of input terminals coupled to a pair of transmitter output terminals. The receiver die includes a pair of receiver input terminals, a pair of output terminals, and a coupler region, with the transmitter die attached to a top surface of the receiver die. The coupler region includes a transmitter coil connected to the pair of transmitter output terminals, a receiver coil positioned proximate to the transmitter coil and connected to the pair of output terminals, a receiver circuit, and a shielding layer positioned between the receiver circuit and the receiver coil. In various embodiments, the signal isolation device includes a signal generator that generates a time-varying voltage at the pair of transmitter output terminals in response to receiving an input signal at the pair of input terminals.

[0006] In some embodiments, a time-varying voltage is coupled to the transmit coil, and in response to receiving the time-varying voltage, the transmit coil induces the receiver coil to generate an intermediate signal corresponding to the input signal. In various embodiments, the receiver die includes power conversion circuitry, where the power conversion circuitry receives the intermediate signal and, in response, the power conversion circuitry generates a DC voltage. In some embodiments, the receiver die includes a driver circuitry that generates a switch drive signal in response to receiving the DC voltage. In various embodiments, the switch drive signal is coupled to a transistor, and the transistor transitions from an off state to an on state in response to receiving the switch drive signal.

[0007] In some embodiments, the signal isolation device further comprises a power storage device coupled to a control circuit, the control circuit being arranged to receive the intermediate signal, wherein in response to receiving the intermediate signal, the control circuit causes the power storage device to generate a DC signal. In various embodiments, the receiver die includes power conversion circuitry arranged to receive the intermediate signal, wherein in response to receiving the intermediate signal, the power conversion circuitry generates a first DC signal at a first voltage and a second DC signal at a second voltage, the first voltage being higher than the second voltage. In some embodiments, the receiver circuitry includes data communications circuitry that demodulates a data signal from the intermediate signal. In various embodiments, the signal isolation device further comprises an encapsulant at least partially encapsulating the transmitter die and the receiver die.

[0008] In some embodiments, the signal isolation device comprises a transmitter die including an input coupled to the transmitter output, and a receiver die, the receiver die including a receiver input, an output, and a coupler region, the receiver input connected to the transmitter output, the coupler region including a transmitter coil connected to the receiver input, a receiver coil connected to the output, a receiver circuit, and a shield positioned between the receiver circuit and the receiver coil.

[0009] In various embodiments, the signal isolation device transmit die includes a signal generator that generates a time-varying voltage at a transmitter output in response to receiving an input signal at the input. In some embodiments, the signal isolation device time-varying voltage is coupled to a transmit coil, and in response to receiving the time-varying voltage, the transmit coil induces the receiver coil to generate an intermediate signal corresponding to the input signal.

[0010] In various embodiments, the signal isolation device receiver die includes power conversion circuitry arranged to receive the intermediate signal, and in response to receiving the intermediate signal, the power conversion circuitry generates a first DC signal at a first voltage and a second DC signal at a second voltage, the first voltage being greater than the second voltage. In some embodiments, the signal isolation device receiver circuitry includes data communications circuitry that demodulates a data signal from the intermediate signal.

[0011] In various embodiments, the signal isolation device receiver die includes a driver circuit that receives a DC signal, where in response to receiving the DC signal, the driver circuit generates a switch drive signal. In some embodiments, the signal isolation device is configured to couple the switch drive signal to a transistor, where the transistor transitions from an off state to an on state in response to receiving the switch drive signal. In various embodiments, the signal isolation device further includes an encapsulant that at least partially encapsulates the transmitter die and the receiver die. [Brief explanation of the drawings]

[0012] [Figure 1A] 1 depicts an exemplary depiction of a signal isolator according to some embodiments of the present disclosure. [Figure 1B] 1B illustrates a simplified cross-sectional view of the signal isolator shown in FIG. 1A. [Figure 1C] 1A illustrates a simplified block diagram of the signal isolator shown in FIGS. 1A and 1B. [Figure 2] 1C illustrates a simplified plan view of a shield that may be used in the signal isolator shown in FIGS. 1A and 1B. [Figure 3] 1 illustrates a simplified partial cross-sectional view of a portion of a signal isolation device according to some embodiments of the present disclosure. [Figure 4A] 1 illustrates a partial plan view of a second shield layer according to some embodiments of the present disclosure. [Figure 4B] 4B illustrates a partial cross-sectional view of the second shield layer shown in FIG. 4A. [Figure 5A] 1 illustrates a partial plan view of a second shield layer according to some embodiments of the present disclosure. [Figure 5B] 5B illustrates a partial cross-sectional view of the second shield layer shown in FIG. 5A. [Figure 6A] 1 illustrates an isometric bottom view of an electronic package of a signal isolation device according to some embodiments of the present disclosure. [Figure 6B]6B illustrates a top isometric view of the electronic package of the signal isolation device shown in FIG. 6A. [Figure 6C] A simplified cross-sectional view is illustrated. [Figure 6D] Illustrates isometric partial perspective drawing. [Figure 7] 7 illustrates a simplified, partially perspective, isometric view of another embodiment of a signal isolation device 700, in accordance with an embodiment of the present disclosure. [Figure 8] 1 illustrates a simplified cross section of a relay device according to an embodiment of the present disclosure. [Figure 9] 1 illustrates a simplified schematic diagram of a multi-channel relay device according to an embodiment of the present disclosure. [Figure 10] 10 illustrates a simplified, partially perspective, isometric view of another embodiment of a relay device 1000, in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the following description, various embodiments are described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that the embodiments may be practiced without the specific details. Additionally, well-known features may be omitted or simplified so as not to obscure the described embodiments.

[0014] Electronic devices often require signals to be communicated between two circuits while maintaining electrical isolation between the two circuits. The electrical isolation between the two circuits may be for reasons of safety, reliability, level translation, and / or multiplexing, for example. The technology disclosed herein generally relates to signal isolators that provide isolation between two circuits while offering a high coupling coefficient in a compact package that can accommodate relatively high voltages. Various inventive embodiments are described herein, including methods, processes, systems, devices, and the like.

[0015] In one example, a signal isolator forms part of a solid-state relay device that electrically isolates a control circuit from a circuit being controlled. In some examples, the isolation between two circuits may be for safety purposes (e.g., to isolate a human interface's control circuit from a power circuit that may have high voltages that are dangerous to humans), while in other examples, the isolation may be for level translation (e.g., the control signal is in one voltage domain (e.g., 3 volts) and the signal being controlled is in another domain (e.g., 1000 volts)). In a further example, multiple signals may be coupled through a single common electrical connection (e.g., a multiplexed input / output connection in an automatic test equipment device), and corresponding multiple signal isolators may be employed to select one signal at a time to be coupled to the common electrical connection. In a further example, a signal isolator may be used to complete a remote connection between a power source and a load without involving the current and / or voltage of the power source coupled to the switch (e.g., to couple a car's starter motor to a battery using a remote switch mounted in the passenger compartment). In some examples, signal isolators may be used to remove harmful or unwanted noise so that noise is not coupled from one circuit to another. The signal isolators disclosed herein may use capacitive, inductive, radiative, optical, acoustic, mechanical, or other suitable methods of coupler coupling.

[0016] In one embodiment, the signal isolator includes a transmitter die attached to a receiver die. The transmitter die includes an input terminal for communicating a signal to a transmitter coil formed on the receiver die. The receiver coil is formed adjacent to, electrically isolated from, and electromagnetically coupled to the transmitter coil such that a signal in the transmitter coil is communicated to the receiver coil. The receiver die includes a rectifier circuit, a voltage amplifier circuit, and a driver circuit that operates a solid-state switch using a signal from the receiver coil. In some embodiments, an electronic package includes the transmitter die, the receiver die, and the solid-state switch.

[0017] Several exemplary embodiments will now be described with reference to the accompanying drawings, which form a part hereof. The following description provides embodiments only and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the following description of the embodiments will provide those skilled in the art with a practical description for implementing one or more embodiments. It will be understood that various changes can be made in the function and arrangement of elements without departing from the spirit and scope of the present disclosure. In the following description, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of particular inventive embodiments. However, it will be apparent that various embodiments can be practiced without such specific details. The drawings and description are not intended to be limiting. As used herein, the words "example" or "exemplary" are used to mean "serving as an example, instance, or illustration." Any embodiment or design described herein as "exemplary" or "example" is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0018] Signal Isolation Devices 1A depicts an exemplary depiction of a signal isolator according to some embodiments of the present disclosure. As shown in FIG. 1A, signal isolation device 100 includes a transmitter die 120 attached to a receiver die 140. Transmitter die 120 has an input terminal 105 that receives an input signal and couples it through the transmitter die to a transmitter output terminal 125. Transmitter output terminal 125 transmits an output signal to a receiver input terminal 135 of receiver die 140. Receiver die 140 generates a corresponding receiver output signal at output terminal 110 while maintaining electrical isolation between input terminal 105 and output terminal 110, as described in more detail below.

[0019] One or more interconnects, e.g., wire bonds 130, may couple the transmitter output terminal 125 to a receiver input terminal 135 disposed on the receiver die 140. The receiver die 140 couples a signal from the receiver input terminal 135 to a coupler 115 formed on the receiver die. The coupler 115 may employ an inductive, capacitive, or other suitable structure to generate an output signal corresponding to the input signal. In one example, the coupler 115 employs a transmit coil that is inductively coupled to a receive coil (not shown in FIG. 1A ). More specifically, when the transmitter output signal is received by the transmit coil, a corresponding signal is generated in the receive coil and transmitted to the output terminal 110. The transmit coil may be electrically isolated from the receive coil to prevent noise or other harmful or undesirable signals from being coupled from the input terminal 105 to the output terminal 110.

[0020] FIG. 1B depicts a simplified cross-sectional view of the signal isolation device 100 shown in FIG. 1A. As shown in FIG. 1B, the coupler 115 is vertically expanded to more clearly illustrate the exemplary features of this particular embodiment. The transmit die 120 may be any suitable type of semiconductor device, including, but not limited to, silicon, and may include transmit circuitry 205 that may perform filtering, amplification, processing, conditioning, and / or other suitable functions on one or more input signals, as described in more detail below. The transmit die 120 may be mechanically and thermally coupled to the receiver die 140 via a bonding layer 210, which may be electrically insulating, electrically conductive, and / or thermally conductive.

[0021] The receive die 140 may be any suitable type of semiconductor device, including, but not limited to, silicon, gallium nitride, gallium arsenide, silicon carbide, silicon germanium, diamond, or other suitable material, as described in more detail below, and may include receive circuitry 215 that may filter, amplify, process, condition, rectify, and / or perform other suitable functions on the received signal.

[0022] Coupler 115 is attached to receive die 140 and may include multiple conductive layers known as "redistribution layers" (RDLs), each separated by one or more dielectric layers 220, such as polyimide. A shielding layer 225 is positioned over receive circuitry 215 to shield the receive circuitry from electromagnetic energy radiated by the area above the shielding layer. In some embodiments, shielding layer 225 may be a continuous or semi-continuous metal layer electrically coupled to ground potential, while in other embodiments, the shielding layer may include two, three, four, or more metal layers, some examples of which are described in more detail below.

[0023] Positioned above the shield layer 225 is a receive coil layer 230. The receive coil layer 230 may include one or more spiral or other suitable geometrically shaped receive coils 235 arranged to receive inductively coupled signals from one or more corresponding transmit coils 240 formed in the transmit coil layer 245. The transmit coils 240 are one or more spiral or other suitable geometrically shaped coils that receive signals from the transmitter die 120 via the transmitter output terminals 125, the conductors 130, and the receiver input terminals 135. In some embodiments, the width of each conductor forming the receive coil 235 and the transmit coil 240 is between 5 and 40 microns, between 10 and 25 microns, or between 12 and 20 microns. In some embodiments, the height of each conductor forming the receive coil 235 and the transmit coil 240 is between 1 and 40 microns, between 5 and 20 microns, or between 5 and 10 microns. In various embodiments, the conductors forming the receive coil 235 and the transmit coil 240 are made from a conductive metal such as, but not limited to, copper, gold, silver, palladium, aluminum, or nickel.

[0024] In some embodiments, the distance between the transmit coil 240 and the receive coil 235 can be 0.1 to 400 microns, 5 to 50 microns, or 10 to 15 microns. Because shorter distances result in higher coupling coefficients and lower electrical isolation, the distance between the transmit coil 240 and the receive coil 235 can vary for different applications requiring specific coupling coefficients and specific electrical isolation ratings. In some embodiments, high dielectric strength materials such as parylene, polyvinylidene fluoride (PVDF), nanocomposites, polyimides, silicon nitride, calcium titanate (CaTiO), or other suitable polymer and / or ceramic materials can be used to shorten the distance between the coils for applications requiring high coupling coefficients along with high electrical isolation. In some embodiments, the coupling coefficient of the transmit coil 240 and the receive coil 235 can be greater than 0.6, greater than 0.7, greater than 0.8, or greater than 0.9. In some embodiments, the distance between the receive coil 235 and the shield 225 is 2 to 20 microns, 3 to 10 microns, or about 4 microns. In some embodiments, the distance between the shield 225 and the receiving circuit 215 is between 0.1 and 20 microns, between 3 and 10 microns, or about 4 microns.

[0025] In some embodiments, one or more additional shielding layers (not shown in FIGS. 1A and 1B) may be formed over the transmit coil 240 and / or over the receiver die 140 positioned on the bottom surface of the transmit die 120. The one or more additional shielding layers may shield the circuitry over each of the transmit coil 240 and receive coil 235 from electromagnetic energy, and each may be formed from one or more metal layers as described in more detail below.

[0026] Vias 250 may electrically couple one or more layers together within coupler 115 and may route signals vertically through receiver die 140. Corresponding apertures 255 may be formed in shield layer 225 to allow vias 250 to pass through one or more shield layers while remaining electrically isolated from the shield layer. For example, vias 250a and 250b may couple signals from receiver input terminal 135 to outer winding 255a of transmitter coil 240 and inner winding 255b of the transmitter coil, respectively. Similarly, vias 250c and 250d may couple signals from outer winding 260a of receiver coil 235 and inner winding 260b of the receiver coil, respectively, to receiver circuitry 215. Via 250e may couple signals from receiver circuitry 215 to the top surface of receiver die 140, where they are to be coupled to a separate electronic device through output terminal 110.

[0027] Although signal isolation device 100 illustrates a particular arrangement of transmit die, transmit coil, receive coil, receiver die, vias, etc., one skilled in the art will recognize that the present disclosure is not limited to this particular arrangement and that other arrangements are within the scope of the present disclosure.

[0028] 1A and 1B. As shown in FIG. 1C, transmit die 120 includes input terminals 105a, 105b, which are arranged to receive an input signal coupled to a transmit coil 240 within coupler 115 by transmitter output terminal 125, electrical conductor 130, and receiver input terminal 135. Receive coil 235 within coupler 115 receives a signal corresponding to the input signal and transmits it to receiver circuitry 215, which generates a corresponding output signal at output terminals 110a, 110b. In this particular embodiment, output terminals 110a, 110b are coupled to switch 270, which is in an on (conducting) state when an input signal is received at input terminals 105a, 105b and is in an off (non-conducting) state when no input signal is received. Other embodiments of the signal isolation device 100 may have different features and functionality, some of which are described in more detail below.

[0029] In some embodiments, the transmit die 120 can be arranged to receive any suitable input signal at input terminals 105a, 105b, such as a steady logic signal (e.g., 0 volts for an “off” signal and 5 volts for an “on” signal) or a varying input (e.g., a 10 kHz input for an on signal and 0 kHz for an off signal). Logic circuitry within the transmit die 120 can determine when an on signal is received at input terminals 105a, 105b and can cause a signal generator to generate a time-varying voltage (e.g., a drive signal) that is coupled to the transmit coil 240. In this particular embodiment, the transmit die 120 includes a pulse generator and a rectifier that generates a driver signal that is coupled to the transmit coil 240 through transmitter output terminal 125, electrical conductor 130, and receiver input terminal 135. In some embodiments, the transmit coil 240 can be coupled to a capacitor 263 (e.g., forming an LC circuit) that has a characteristic resonant frequency. The transmit die 120 may drive the LC circuit at its resonant frequency, although in other embodiments, the transmit die 120 may drive the LC circuit at a higher or lower resonant frequency. In some embodiments, the transmit die 120 may drive the LC circuit at different frequencies, for example, the transmit die 120 may drive the LC circuit at a lower resonance for a first period of time and then at resonance for a second period of time.

[0030] Within the coupler 115, the time-varying electrical signal in the transmit coil 240 is electromagnetically coupled to the receive coil 235. In some embodiments, ferrite or other material may be positioned between the transmit coil 240 and the receive coil 235 to increase the coupling coefficient between the two coils. The receive coil 235 may be coupled in series with a capacitor 237 (forming an LC resonant circuit) and may generate a signal corresponding to the drive signal for the transmit coil 240. In some embodiments, the resonant frequencies of the transmit coil and the receive coil may match, while in other embodiments, the resonant frequencies may differ. In some embodiments, the number of turns in the transmit coil 240 and the receive coil 235 may be equal, while in other embodiments, one may have more or fewer turns than the other. As discussed in more detail herein, the signal generated by the receive coil 235 may be used by the receiver die 140 to operate one or more switches to generate power and / or communicate data.

[0031] 1C , receiver circuit 215 includes a power converter 260 that can convert the power received from receiver coil 235 to a higher or lower voltage. In one embodiment, power converter 260 is a charge pump circuit that boosts the voltage and may further include a rectifier that rectifies the time-varying electrical signal received from receiver coil 235 to generate a DC voltage. In further embodiments, power converter 260 may include a converter of a half-bridge, full-bridge, or other suitable architecture, which may include any suitable AC-DC and / or DC-DC converter.

[0032] In further embodiments, power converter 260 may include two or more power outputs that may supply different voltages to one or more auxiliary circuits. In some embodiments, power converter 260 may include two or more DC-DC converters that generate any suitable voltages for one or more auxiliary outputs. In further embodiments, power converter 260 may include low dropout regulators (LDOs), voltage dividers, or other circuits to generate different "auxiliary" voltages.

[0033] 1C , power converter 260 may rectify and increase the voltage of the signal received from receiver coil 235 and transmit the rectified, higher voltage signal to driver circuit 265. Driver circuit 265 may provide a drive signal to switch 270 when an “on” signal is detected by transmit die 120. Driver circuit 265 may include one or more pull-down and / or pull-up transistors to latch switch 270 in an on or off state and to supply the necessary voltage and current to switch 270.

[0034] 1C , switch 270 is arranged as two switches connected back-to-back in a bidirectional configuration with both gates of both switches operated simultaneously by driver circuit 265. However, in other embodiments, the switches may be a single integrated switch pair or other suitable arrangements, such as a single MOSFET, HEMT, IGBT, or other type of switch. When switch 270 is in an on state, first relay terminal 275 a is electrically coupled to second relay terminal 275 b, and when switch 270 is in an off state, the first relay terminal is isolated from the second relay terminal. In some embodiments, multiple switches (bidirectional or other types), such as two, three, four, or more, may be operated by driver circuit 265 and / or switch 270.

[0035] In another embodiment, the receive circuitry 215 may include data communication circuitry (not shown in FIG. 1C ) that may be coupled to the receive coil 235 and configured to demodulate data signals from the receive coil. For example, in one embodiment, the transmit die 120 may include data modulation circuitry that couples data to the transmit coil 240 such that the transmit coil may couple both a power signal (e.g., 100 MHz) and a data signal (e.g., operating at 10 kHz) to the receive coil 235, thereby simultaneously transmitting both power and data through the coupler 115.

[0036] In further embodiments, the signal isolation device 100 may operate bidirectionally as a power and / or data communication system. More specifically, in one embodiment, power and / or data may be transferred from the transmit coil 240 to the receive coil 235, and power and / or data may be transferred conversely from the receive coil 235 to the transmit coil 240. For example, data may be communicated from the receive coil 235 to the transmit coil 240, while power may be transferred by the receiver circuitry 215 from the transmit coil 240 to the receive coil 235, changing the effective impedance of the receive coil 235, which can be sensed by circuitry coupled to the transmit coil 240 and received as data for the transmit die 120. In some embodiments in which the signal isolation device 100 is bidirectional, the power converter 260 may include a bidirectional DC-DC converter, such that the signal or power received from the output terminals 110a, 110b may have its voltage level changed and / or inverted to an AC signal for communicating the data and / or power to the transmit die 120 and / or the input terminals 105a, 105b. Thus, in some embodiments, power transfer may be unidirectional in either direction while data transfer is bidirectional, in further embodiments both power and data may be bidirectional, and in still other embodiments data transfer may be unidirectional in either direction while power transfer is bidirectional.

[0037] In some embodiments, signal isolation device 100 may include (e.g., co-packaged) a power storage device and / or may be arranged to control a power storage device (e.g., a separate electronic device). In various embodiments, the power storage device may be a capacitor co-packaged with the signal isolation device circuitry in a common electronic package, and the signal isolation device includes control circuitry configured to charge the power storage device during a charging cycle. In some embodiments, the charging cycle may occur at a relatively low drive frequency to reduce EMI generation. After or while the power storage device is charged, a data signal may be sent by transmit die 120 to receive die 140 to turn on switch 270. Driver circuit 265 may use power stored in the power storage device to turn on switch 270. Using a power storage device may increase the speed at which switch 270 operates because power to operate the switch is immediately available from the power storage device and does not need to be sent across coupler 115. In further embodiments, power from both coupler 115 and the power storage device may be used to turn on switch 270.

[0038] In some embodiments, the receiver circuit 215 may be formed on a monolithic receive die 140 and may include the power converter 260 and the driver circuit 265 with the switch 270 formed on a separate die, while in other embodiments, the switch 270 may be monolithically formed on the receive die. In various embodiments, one or more components of the receiver circuit 215 may be co-packaged with the receiver die 140 and / or positioned on a circuit board adjacent to the signal isolation device 100. In some embodiments, the receive die 140 may be formed from silicon, silicon carbide, gallium arsenide, gallium nitride, diamond, or any other suitable semiconductor material. In some embodiments, the transmit die 120 may be formed from silicon, silicon carbide, gallium arsenide, gallium nitride, diamond, or any other suitable semiconductor material. In some embodiments, the switch 270 may be formed from silicon, silicon carbide, gallium arsenide, gallium nitride, diamond, or any other suitable semiconductor material.

[0039] FIG. 2 illustrates a simplified plan view of a shield 225 that may be used in the signal isolation device 100 shown in FIGS. 1A and 1B. As shown in FIG. 2, the shield 225 includes what may be metal conductors arranged in a herringbone pattern with relatively small gaps between each conductor. In some embodiments, the width of each conductor may be 20-40 microns, and the gap between each conductor may be 2-10 microns. Such an arrangement may be beneficial for reducing and / or eliminating the formation of eddy currents, thereby improving the effectiveness of shielding the receiver circuit 215 (see FIG. 1B) from electromagnetic noise generated by the transmitter coil 240 and / or the receiver coil 235, respectively. The shield 225 may be formed from any suitable conductive metal, such as, but not limited to, copper, gold, silver, palladium, aluminum, titanium, or nickel.

[0040] The shield 225 may include one or more apertures 255 that allow vias 250 (see FIG. 1B) to pass through the layers. In some embodiments, the shield 225 may have different configurations and / or may include two or more layers, as described in more detail below.

[0041] FIG. 3 illustrates a simplified partial cross-sectional view of a portion of a signal isolation device 300. As shown in FIG. 3, the signal isolation device 300 may be similar to the signal isolation device 100 shown in FIGS. 1A and 1B, except that the signal isolation device 300 may use a second shielding layer 305 in addition to the first shielding layer 225 shown in FIGS. 1B and 2. The signal isolation device 300 includes a transmit coil 310 separated from a receive coil 315 by a dielectric layer 320. One or more vias 325 provide electrical interconnections between the one or more layers. In some embodiments, the second shielding layer 305 may be a continuous or semi-continuous metal layer made from a conductive metal such as, but not limited to, copper, gold, silver, palladium, aluminum, or nickel. In some embodiments, the second shielding layer 305 may include one, two, three, four, or more layers, some of which are described in more detail below. In other embodiments, the vertical order of the first shield layer 225 and the second shield layer 305 may be reversed.

[0042] FIG. 4A illustrates a partial plan view of the second shield layer 305, and FIG. 4B illustrates a partial cross-sectional view. As shown in FIGS. 4A and 4B, the second shield layer 305 may include a first layer 405 having a series of parallel first conductors 410 with gaps between them and a second layer 415 having a series of parallel second conductors 420 with gaps between them. The first conductors 410 may be arranged to be parallel to the second conductors 420, with the first conductors covering the gaps between the second conductors and the second conductors offset from the second conductors such that the first conductors cover the gaps between the first conductors. This arrangement may block the electric field in the first gaps, thereby preventing the electric field extending through the first gaps from penetrating the second shield layer. One or more dielectric layers (not shown in FIGS. 4A, 4B) may be positioned between the first layer 405 and the second layer 415. In some embodiments, the shielding layer 305 may be used alone (e.g., as the first shielding layer), while in other embodiments, the shielding layer 305 may be used in combination with one or more other shielding layers. The second shielding layer 305 may be a continuous or semi-continuous metal layer made from a conductive metal such as, but not limited to, copper, gold, silver, palladium, aluminum, or nickel. In some embodiments, the width of each conductor may be increased or decreased by a suitable amount compared to the scale shown in FIGS. 4A and 4B.

[0043] FIG. 5A illustrates a partial plan view, and FIG. 5B illustrates a partial cross-sectional view, of another embodiment of second shield layer 305. As shown in FIGS. 5A and 5B, second shield layer 305 may include a first layer 505 having a series of parallel first conductors 510 with gaps therebetween and a second layer 515 having a series of parallel second conductors 520 with gaps therebetween. First conductors 510 may be arranged perpendicular to second conductors 520. One or more dielectric layers (not shown in FIGS. 5A and 5B) may be positioned between first layer 505 and second layer 515. In some embodiments, second shield layer 305 may be used alone (e.g., as a first shield layer), while in other embodiments, second shield layer 305 may be used in combination with one or more other shield layers. The second shielding layer 305 may be a continuous or semi-continuous metal layer made from a conductive metal such as, but not limited to, copper, gold, silver, palladium, aluminum, or nickel. In some embodiments, the width of each conductor may be increased or decreased by a suitable amount compared to the scale shown in Figures 5A and 5B.

[0044] 1A-5B may be used alone or in combination with one another such that a signal isolation device includes one, two, three, four, or more shield layers. Furthermore, the shield layers may be arranged in any suitable vertical order, and repeated use of one or more shield layer configurations is within the scope of this disclosure.

[0045] FIG. 6A illustrates an isometric bottom view of a signal isolation device electronic package 600 that may encapsulate the signal isolation device described above with reference to FIGS. 1A and 1B according to an embodiment of the present disclosure. FIG. 6B illustrates a top isometric view of electronic package 600, FIG. 6C shows a simplified cross-sectional view, and FIG. 6D illustrates an isometric partial perspective view. Electronic package 600 is known as a dual flat no-lead (DFN) package, but the present disclosure is not limited to this structure; other types of suitable packages, such as quad flat no-lead (QFN), small outline (SO), multi-chip module, chip-scale package (CSP), etc., are within the scope of the present disclosure. For example, a QFN package may be used to package two, three, four, or more signal isolation devices 100 in a single electronic package.

[0046] 6A and 6B, an electronic package 600 may include a body 605 formed from a dielectric molding material formed around a transmitter die and a receiver die (not shown in FIGS. 6A and 6B). The electronic package may include one or more external terminals 610 that may be coupled to a circuit board or other electronic structure and that couple input and output signals to the transmitter and receiver die within the electronic package.

[0047] 6C, external terminals 610 may be formed from a metal layer 615, which may be a lead frame or other structure. Receiver die 140 is attached to center terminal 610e, with input terminals 105 on transmitter die 120 electrically coupled to external input terminals 610a-610d, and output terminals 110 on receiver die 140 electrically coupled to external output terminals 610f-610i. Electrical coupling within electronic package 600 may be via wire bonding, flip-chip interconnections, or other suitable interconnect structures.

[0048] As shown in FIG. 6D , the transmit coil 240 and the receive coil 235 are each positioned across a majority of the area of the receiver die 140 to maximize mutual inductance. In various embodiments, the area of the receiver die 140 is approximately 1 square millimeter, and the coils are distributed across more than 60 percent of the area, more than 70 percent of the area, more than 80 percent of the area, or 90-100 percent of the area. In some embodiments, one or more active and / or passive electronic components (e.g., resistors, capacitors, inductors, diodes, transistors, etc.) can be integrated within the package 600. For example, circuitry can be implemented to convert received signals to DC power for powering other circuitry on the receiver die and / or for powering external components outside the package. As another example, circuitry can be implemented to enable signals to be recoupled from the receiver chip to the transmitter chip to facilitate bidirectional data and / or power transfer. In yet another example, matching components (e.g., capacitors and / or resistors for improved insertion loss and / or return loss), filtering, and / or decoupling capacitors may be coupled to the input and / or output terminals to improve device and / or system performance.

[0049] In some embodiments, electronic package 600 may have one or more integrated heat sinks formed from a thermally conductive material and positioned to transfer thermal energy away from receiver die 140 and / or transmitter die 120. In some embodiments where package 600 is transferring a relatively large amount of power from the input terminals to the receiver terminals, the heat sinks may be used to remove heat from the die and transfer the heat to a circuit board to which package 600 is mounted and / or to an external heat sink that may be mounted to the top surface of the electronic package.

[0050] FIG. 7 illustrates a simplified, partially perspective, isometric view of another embodiment of a signal isolation device 700 in accordance with an embodiment of the present disclosure. The signal isolation device 700 may be or may include any of the components, features, or characteristics of any of the signal isolation devices described above. As shown in FIG. 7 , the signal isolation device 700 may be a chip-scale package in which a transmit die 705 is attached to a receiver die 710. Input terminals 715 a, 715 b, which may be solder balls, couple the input signal to the transmit die 705. The input signal propagates to the transmit die 705 through respective vias 717 a, 717 b (717 b is not shown in FIG. 7 ) disposed in the receiver die 710 and through respective chip-to-chip interconnects 720 a, 720 b (shown as wire bonds in FIG. 7 but which may be flip-chip interconnects or other suitable interconnects in other embodiments).

[0051] The transmitter die 705 may perform any of the operations described above on the input signal, including converting the input signal to an intermediate signal having a time-varying voltage. The intermediate signal may be coupled to the receiver die 710 through inter-chip interconnects 720c, 720d (shown as wirebonds in FIG. 7 but which may be flip-chip interconnects or other suitable interconnects in other embodiments). The receiver die 710 conducts the signal to a coupler 730, which may include one or more redistribution layers that couple the intermediate signal from the transmitter coil to the isolated receiver coil, as described in more detail above. The receiver die 710 conducts the signal from the receiver coil to output terminals 715c, 715d (715d not shown in FIG. 7) through respective vias 717c, 717d (717d not shown in FIG. 7). In some embodiments, the transmit die 705 may include one or more shielding layers and / or the receiver die 710 may include one or more additional shielding layers above or below the transmit / receive coils to shield the receiver circuitry from electromagnetic fields generated by the transmit and receive coils, some of which are described in more detail above.

[0052] The terminals 715 may be or include solder balls, copper pillars, columns, or any other suitable type of interconnect. An electrically insulating encapsulant 725 may fully or partially encapsulate the transmitter die 705 and / or the receiver die 710. A chip-scale packaging configuration may allow the signal isolation device 700 to be smaller than the electronic packages shown in FIGS. 6A-6D and may also allow circuitry to be integrated above and below the transmit / receive coils. In some embodiments, the active circuitry of the receiver die 710 is formed on the bottom surface 713 of the receiver die, which provides higher electrical isolation between the transmit / receive coils and the active receiver circuitry, while in other embodiments, the active receiver circuitry may be formed on the top surface. In further embodiments, the active circuitry of the transmitter die 705 may be formed on the top surface (shown in FIG. 7), which may provide higher isolation between the active transmitter circuitry and the transmit / receive coils, while in other embodiments, the active circuitry may be formed on the bottom surface.

[0053] Solid State Relay Device FIG. 8 illustrates a simplified cross-section of a relay device according to an embodiment of the present disclosure. As shown in FIG. 8, relay device 800 can include a signal isolation device 803, which can be similar to signal isolation device 100 shown in FIGS. 1A-5B, but relay device 800 also includes one or more switches 804 that operate in response to an input signal. Relay device 800 can be or include any of the components, features, or characteristics of the signal isolation devices described above, and relay devices can be included in any of the signal isolation devices discussed above. In one embodiment, relay device 800 can include two back-to-back transistors (e.g., two transistors with source terminals connected together) that operate as a bidirectional switch 804. The transistors are turned on in response to an input signal and turned off in the absence of an input signal, thus operating as a solid-state relay. In some embodiments, switch 804 consists of two back-to-back gallium nitride field effect transistors (GaN FETs), and signal isolation device 803 generates sufficient current (e.g., greater than 100 microamperes) to operate the GaN FETs. In a further embodiment, the bidirectional switch 804 may be replaced by a single GaN FET.

[0054] 8A , relay device 800 includes one or more input terminals 805 that receive one or more input signals, one or more output terminals 810 that transmit one or more corresponding output signals to switch 804, and a coupler 815 that couples the one or more input signals to the one or more output terminals, as described in more detail above. In this particular embodiment, signal isolation device 803 includes a transmit die 820 that includes one or more input terminals 805. Transmitter die 820 couples the input signals to transmitter output terminals 825 and may also filter, amplify, process, condition, or perform other suitable functions on the one or more input signals.

[0055] One or more interconnects, e.g., wire bonds 830, may couple the first transmitter output terminal 825 to a receiver input terminal 835 disposed on the receiver die 840. The receiver die 840 couples signals from the receiver input terminal 835 to a coupler 815 formed on the receiver die. The coupler 815 may employ an inductive, electrostatic, or other suitable structure to generate one or more output signals corresponding to the one or more input signals. In one example, the coupler 815 employs a transmit coil that is inductively coupled to a receive coil (not shown in FIG. 8 ). More specifically, when an input signal is received by the transmit coil, a corresponding signal is generated in the receive coil and transmitted to one or more output terminals 810. The transmit coil may be electrically isolated from the receive coil to prevent noise or other harmful or undesirable signals from being coupled from the one or more input terminals 805 to the one or more output terminals 810.

[0056] One or more output terminals 810 may be coupled to switch 804 via interconnects, e.g., wirebonds 830, which may connect to a gate terminal 845 of switch 804. Thus, when a sufficient input signal is received by input terminal 805, output terminal 810 conducts current to gate terminal 845, transitioning switch 804 from an off state to an on state. Corresponding relay terminals 850 a, 850 b are coupled together when the switch is in an on state and are decoupled when the transistor is in an off state. Relay terminals 850 a, 850 b may be connected to external relay terminals outside of package 875.

[0057] In some embodiments, switch 804 can withstand relatively high voltages, such as greater than 100 volts, greater than 150 volts, greater than 200 volts, greater than 500 volts, greater than 800 volts, or greater than 1000 volts. In various embodiments, switch 804 may be comprised of one or more transistors formed from silicon, silicon carbide, gallium arsenide, gallium nitride, diamond, or any other suitable semiconductor material. In some embodiments, switch 804 may include a single transistor operating as a unidirectional switch, two or more switches operating as bidirectional switches, or three or more switches operating in a T-switch configuration. A T-switch configuration may be useful for minimizing leakage current at the test terminals and may include three solid-state relays or “switches” arranged in a “T” configuration to minimize leakage current between the output to the test instrument and the test signal input. In further embodiments, switch 804 may include one or more electrically isolated unidirectional, bidirectional, and / or T-switch circuits.

[0058] 8 , the transmit die 820, receive die 840, and switch 804 devices are disposed within an electronic package including a substrate 880 overmolded with a dielectric mold compound 885 and may be known as a multi-chip module. However, other suitable types of electronic packages, such as a very thin small outline no-lead package (VSON), dual flat no-lead (DFN), quad flat no-lead (QFN), small outline (SO), or chip-scale package (CSP), may be used within the scope of this disclosure. Furthermore, multiple signal isolation / transistor devices may be included within a single electronic package; for example, a QFN package may be used to package two, three, four, or more signal isolation / transistor devices within a single electronic package. In various embodiments, one or more active and / or passive electronic components (e.g., resistors, capacitors, inductors, diodes, transistors, etc.) may be integrated within package 875. For example, matching components (e.g., capacitors and / or inductors and / or resistors to improve insertion loss and / or return loss), filtering capacitors, and / or decoupling capacitors may be coupled to the input and / or output terminals to improve device and / or system performance. In another example, transistor driver circuitry may be integrated within package 875 that provides a robust, noise-immune, and reliable drive signal to switch 804.

[0059] 9 illustrates a simplified schematic diagram of a multi-channel relay device according to an embodiment of the present disclosure. As shown in FIG. 9, the multi-channel relay device 900 may be similar to the relay device 800 shown in FIG. 8, but the relay device 900 has a first outlet channel 905 and a second outlet channel 910 that are driven by a common input 915 and are electrically isolated, as described in more detail below.

[0060] In some embodiments, the structure of the multi-channel relay device 900 may be similar to the relay device 800, except that a coupler disposed on the receiver die includes a first receive coil 920 and a second receive coil 925, each inductively coupled to a single transmit coil 930. Thus, when the transmit coil 930 is energized, it induces a signal in both the first receive coil 920 and the second receive coil 925, which are coupled to a first transistor 935 and a second transistor 940, respectively. While the first transistor 935 and the second transistor 940 are each illustrated as two back-to-back transistors in this embodiment, in other embodiments, these transistors may be a single transistor or other suitable device. In further embodiments, the coupler region in any of the embodiments described herein may be replaced with an optocoupler device, a capacitive coupling device, or other suitable coupler.

[0061] 10 illustrates a simplified, partially perspective, isometric view of another embodiment of a relay device 1000 in accordance with an embodiment of the present disclosure. The relay device 1000 may be or include any of the components, features, or characteristics of any of the signal isolation devices or relay devices described above. As shown in FIG. 10, the relay device 1000 may be a chip-scale package in which a transmit die 1005 is attached to a receiver die 1010, which in turn is attached to a switch die 1012. Input terminals 1015a, 1015b, which may be solder balls, couple input signals to the transmit die 1005. The input signal propagates through respective vias 1017a, 1017b (1017b not shown in FIG. 10) disposed within the switch die 1012, through respective inter-chip interconnects 1020a, 1020b (shown as wire bonds in FIG. 10, but which in other embodiments may be flip-chip interconnects or other suitable interconnects) to the transmitter die 1005.

[0062] The transmitter die 1005 may perform any of the operations described above on an input signal, including converting the input signal to an intermediate signal having a time-varying voltage. The intermediate signal may be coupled to the receiver die 1010 through inter-chip interconnects 1020c, 1020d (shown as wirebonds in FIG. 10 but which may be flip-chip interconnects or other suitable interconnects in other embodiments). The receiver die 1010 conducts the signal to a coupler 1030, which may include one or more redistribution layers, such as those described in more detail above, that couples the intermediate signal from the transmit coil to an isolated receive coil. The receiver die 1010 conducts the signal from the receive coil to a switch die 1012, which includes one or more solid-state switches. In some embodiments, one or more solid-state switches are located on the bottom surface 1013 of the switch die, and thus vias 1017c, 1017d (1017d not shown in FIG. 10) conduct the signal to the one or more switches. The one or more switches may operate to create an electrical connection between output terminals 1015c, 1015d (1015d not shown in FIG. 10 ) in response to input terminals 1015a, 1015b receiving an input signal. In some embodiments, switch die 1012 may include a redistribution layer and / or a shielding layer 1035, which may provide signal routing and / or signal shielding capabilities. In further embodiments, one or more switch driver circuits for operating the one or more solid-state switches may also be formed on the bottom surface 1013, while in other embodiments, the switch driver circuits may be formed on the receiver die 1010. In some embodiments, the transmit die 1005 may include one or more shielding layers, and / or the receiver die 1010 may include one or more additional shielding layers above or below the transmit / receive coils (in coupler 1030) to shield the receiver circuitry from electromagnetic fields generated by the transmit and receive coils, some of which are described in more detail above.

[0063] The terminals 1015 may be or include solder balls, copper pillars, columns, or any other suitable type of interconnect. An electrically insulating encapsulant 1025 may fully or partially encapsulate the transmit die 1005, the receiver die 1010, and / or the switch die 1012. A chip-scale packaging configuration may allow the relay device 1000 to be smaller than the electronic package shown in FIG. 8 and may also allow circuitry to be integrated above and below the transmit / receive coils. In some embodiments, the active circuitry of the receiver die 1010 is formed on the bottom surface of the receiver die, which provides higher electrical isolation between the transmit / receive coils and the active receiver circuitry, while in other embodiments, the active receiver circuitry may be formed on the top surface. In further embodiments, the active circuitry of the transmit die 1005 may be formed on the top surface (shown in FIG. 10 ), which may provide higher isolation between the active transmit circuitry and the transmit / receive coils, while in other embodiments, the active circuitry may be formed on the bottom surface.

[0064] In the foregoing specification, embodiments of the present disclosure have been described with reference to numerous specific details that may vary depending on the implementation. Accordingly, the specification and drawings should be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indication of the scope of the present disclosure, and what the applicant intends to be the scope of the present disclosure, is the literal and equivalent scope of the series of claims issuing from this application in the particular form in which such claims are issued, including any subsequent amendments. The specific details of particular embodiments can be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present disclosure.

[0065] Additionally, spatially relative terms such as "bottom" or "top" may be used to describe the relationship of one element and / or feature to another, for example, as illustrated in the figures. It will be understood that spatially relative terms are intended to encompass different orientations of the device during use and / or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, an element described as the "bottom" surface may then be oriented "on top" of the other element or feature. The device may be oriented differently (e.g., rotated 90 degrees or to another orientation) and the spatially relative descriptors used herein interpreted accordingly.

[0066] As used herein, the terms “and,” “or,” and “and / or” can have a variety of meanings that are expected to depend, at least in part, on the context in which such terms are used. Typically, “or” when used to associate a list, such as A, B, or C, is intended to refer to A, B, and C, which are used herein in an inclusive sense, as well as A, B, or C, which are used herein in an exclusive sense. Additionally, as used herein, the term “one or more” may be used to describe any feature, structure, or characteristic in the singular, or may be used to describe some combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and claimed subject matter is not limited to this example. Furthermore, the term “at least one of,” when used to associate a list, such as A, B, or C, can be interpreted to mean any combination of A, B, and / or C, such as A, B, C, AB, AC, BC, AA, AAB, ABC, AABBCCC, etc.

[0067] Throughout this specification, references to "one example," "one example," "particular example," or "exemplary implementation" mean that a particular feature, structure, or characteristic described in connection with a feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Thus, appearances of the phrases "in one example," "in one example," "particular example," "in a particular implementation," or other similar phrases in various places throughout this specification do not necessarily all refer to the same features, examples, and / or limitations. Furthermore, particular features, structures, or characteristics may be combined in one or more examples and / or characteristics.

[0068] In some implementations, operations or processing may involve physical manipulations of physical quantities. Typically, though not necessarily, such quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It has proven convenient at times, primarily for reasons of common usage, to refer to signals as bits, data, values, elements, symbols, characters, terms, numbers, numerals, or the like. It should be understood, however, that all of these or similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically indicated otherwise, as will be apparent from the discussion herein, discussions throughout this specification utilizing terms such as “processing,” “computing,” “calculating,” “determining,” and the like will be understood to refer to acts or processes of a particular apparatus, such as a special purpose computer, a special purpose computing device, or a similar special purpose electronic computing device. Thus, in the context of this specification, a special purpose computer or a similar special purpose electronic computing device can manipulate or transform signals, which are typically represented as physical electronic or magnetic quantities in the memories, registers, or other information storage, transmission, or display devices of the special purpose computer or similar special purpose electronic computing device.

[0069] One or more of the embodiments disclosed herein may have the following features. 1. A method of operating a signal isolation device, the method comprising: receiving an input signal at an input of the transmitting die and generating a corresponding time-varying voltage at a transmitter output of the transmitting die in response to receiving the input signal; coupling a time-varying voltage from a transmitter output of the transmitting die to a receiver input of the receiver die; coupling a time-varying voltage from a receiver input to a transmit coil disposed within the receiver die; inducing a receive coil to generate an intermediate signal in response to coupling a time-varying voltage to the transmit coil, the intermediate signal corresponding to the input signal, the receive coil being disposed within a receiver die; coupling the intermediate signal to receiver circuitry disposed within the receiver die; and shielding electromagnetic noise generated by the receive coil from the receiver circuitry via a shield positioned between the receive coil and the receiver circuitry. 2. The method of claim 1, further comprising electrically isolating the transmit coil from the receive coil. 3. The method of claim 1, further comprising converting the intermediate signal to a DC signal via a power conversion circuit. 4. The method of claim 3, wherein the input signal corresponds to and is electrically isolated from a DC signal. 5. The method of claim 3, wherein the DC signal is a first DC signal and the power conversion circuit generates a second DC signal having a higher voltage than the first DC signal. 6. The method of claim 1, wherein the transmit die includes a data modulation circuit that couples data into a time-varying voltage. 7. The method of claim 1, wherein the receiver circuitry includes a data demodulation circuitry that demodulates data from the intermediate signal. 8. A method of forming a signal isolation device, the method comprising: Attaching a transmitter die to a receiver die, the transmitter die including a pair of input terminals coupled to a pair of transmitter output terminals, the receiver die including a pair of receiver input terminals, a pair of output terminals, and a coupler region, the coupler region comprising: A transmitting coil; a receiver coil positioned adjacent to the transmitter coil and connected to a pair of output terminals; a receiver circuit connected to the receiver coil; a shielding layer positioned between the receiver circuit and the receiver coil; forming one or more electrical connections between the transmitter die and the receiver die such that the transmitter coil is connected to a pair of transmitter output terminals; and at least partially encapsulating the transmitter die and the receiver die with an electrically insulating material. 9. The method of claim 8, wherein the transmitter die includes a transmitter circuit arranged to generate a time-varying voltage in response to receiving an input signal at the input terminal. 10. The method of claim 9, wherein a time-varying voltage is coupled to the transmitter coil, and in response to receiving the time-varying voltage, the transmitter coil induces the receiver coil to generate an intermediate signal corresponding to the input signal. 11. The method of claim 10, wherein the signal isolation device further comprises a power storage device coupled to the receiver circuit, the receiver circuit configured to generate a DC signal in the power storage device in response to generation of the intermediate signal. 12. The method of claim 10, wherein the receiver circuit generates a DC voltage in response to generating the intermediate signal. 13. The method of claim 12, wherein the DC voltage is a first DC voltage, and the receiver circuit generates a second DC voltage in response to the generation of the intermediate signal, the second DC voltage being higher than the first DC voltage. 14. The method of claim 12, wherein the DC voltage is coupled to a switch driver circuit that generates the switch drive signal. 15. The method of claim 10, wherein the transmitting die includes a data modulation circuit that modulates data onto a time-varying voltage. 16. The method of claim 15, wherein the receiver circuitry includes a data demodulation circuitry that demodulates data from the intermediate signal. 17. A method of operating a signal isolation device, the method comprising: receiving an input signal at an input of a signal isolation device; coupling the input signal to a transmit circuit disposed on the transmit die, the transmit circuit generating a corresponding time-varying voltage in response to receiving the input signal; coupling a time-varying voltage from a transmit circuit to a transmit coil disposed in a separate receiver die; inducing a receive coil to generate an intermediate signal in response to coupling a time-varying voltage to the transmit coil, the intermediate signal corresponding to the input signal, the receive coil being disposed within a receiver die; coupling the intermediate signal to receiver circuitry disposed within the receiver die; generating an output signal at an output of the signal isolation device in response to coupling the intermediate signal to a receiver circuit, the output signal corresponding to the input signal, and the output signal being electrically isolated from the input signal. 18. The method of claim 17, further comprising shielding electromagnetic noise generated by the receive coil from the receiver circuitry via a shield positioned between the receive coil and the receiver circuitry. 19. The method of claim 17, wherein the receiver circuitry includes an AC-to-DC converter circuitry that receives the intermediate signal and responsively generates a DC voltage output signal. 20. The method of claim 19, wherein the output signal is a first output signal and the receiver circuit generates a second output signal.

[0070] One or more of the embodiments disclosed herein may have the following features. 1. A solid-state relay device comprising: a transistor die including a transistor having a gate terminal, a source terminal, and a drain terminal; a transmitter die including a pair of input terminals coupled to a pair of transmitter output terminals; a receiver die, the receiver die including a pair of receiver input terminals, a pair of output terminals, and a coupler region; a transmitter die attached to a top surface of the receiver die, at least one output terminal of the pair of output terminals attached to a gate terminal; and the coupler region a transmitting coil connected to a pair of receiver input terminals; a receiver coil positioned adjacent to the transmitter coil and connected to a pair of output terminals; a receiver circuit; a shielding layer positioned between the receiver circuit and the receiver coil. 2. The solid-state relay device of claim 1, wherein the transistor is a first transistor, the source terminal is a first source terminal, and the electronic device further comprises a second transistor having a second source terminal, the first source terminal being connected to the second source terminal. 3. The solid-state relay device of claim 2, wherein the second transistor includes a second gate terminal connected to at least one output terminal of the pair of output terminals. 4. The solid-state relay device of claim 1, wherein the transmitter die is attached to a top surface of the receiver die, and the receiver die is attached to a top surface of the transistor die. 5. The solid-state relay device of claim 1, wherein the receiver coil is a first receiver coil, the pair of output terminals is a pair of first output terminals, and the receiver die includes a second receiver coil positioned proximate to the transmitter coil and connected to a pair of second output terminals. 6. The solid-state relay device of claim 5, wherein the transistor is a first transistor and the electronic device comprises a second transistor having a second gate terminal coupled to at least one output terminal of the pair of second output terminals. 7. The solid-state relay device of claim 6, wherein the first transistor comprises a first bidirectional switch and the second transistor comprises a second bidirectional switch. 8. The solid-state relay device of claim 5, wherein a first receiver coil is positioned adjacent to a first surface of the transmitter coil, and a second receiver coil is positioned adjacent to a second surface of the transmitter coil, the first surface facing the second surface. 9. The solid state relay device of claim 1, further comprising an energy storage device coupled to the gate terminal and arranged to apply power to the gate terminal in response to an input signal at the input terminal. 10. The solid state relay device of claim 1, further comprising an encapsulant that at least partially encapsulates the transistor die, the transmitter die, and the receiver die. 11. A relay device, comprising: a switch die including a solid-state switch having a source, a drain, and a gate; a transmitter die including an input coupled to a transmitter output; a receiver die including a receiver input, an output, and a coupler region, the receiver input connected to the transmitter output, the output coupled to the gate, and the coupler region a transmit coil connected to the receiver input; a receiver coil connected to the output; a receiver circuit; a shield positioned between the receiver circuit and the receiver coil. 12. The relay device of claim 11, wherein the solid-state switch is a first solid-state switch, the source is a first source, and the electronic device further comprises a second solid-state switch having a second source, the first source being connected to the second source. 13. The relay device of claim 12, wherein the second solid-state switch includes a second gate coupled to the output. 14. The relay device of claim 11, wherein the transmitter die is attached to a top surface of the receiver die, and the receiver die is attached to a top surface of the switch die. 15. The relay device of claim 11, wherein the receiver coil is a first receiver coil, the output is a first output, and the receiver die includes a second receiver coil positioned proximate to the transmitter coil and connected to the second output. 16. The relay device of claim 15, wherein the solid-state switch is a first solid-state switch and the electronic device comprises a second solid-state switch having a second gate coupled to the output. 17. The relay device of claim 16, wherein the first solid-state switch comprises a first bidirectional switch and the second solid-state switch comprises a second bidirectional switch. 18. The relay device of claim 15, wherein a first receiver coil is positioned adjacent to a first surface of the transmitter coil, and a second receiver coil is positioned adjacent to a second surface of the transmitter coil, the first surface facing the second surface. 19. The relay device of claim 11, further comprising an energy storage device coupled to the gate and arranged to apply power to the gate in response to an input signal at the input. 20. The solid state relay device of claim 11, further comprising an encapsulant that at least partially encapsulates the switch die, the transmitter die, and the receiver die.

[0071] One or more of the embodiments disclosed herein may have the following features. 1. A method of operating a solid state relay device, the method comprising: generating a corresponding time-varying voltage at a transmitter output of the transmitting die in response to receiving an input signal; and coupling the time-varying voltage from the transmitter output of the transmitting die to a receiver input of the receiver die; coupling a time-varying voltage from a transmitter output of the transmitting die to a receiver input of the receiver die; coupling a time-varying voltage from a receiver input to a transmit coil disposed within the receiver die; inducing a receive coil to generate an intermediate signal in response to coupling a time-varying voltage to the transmit coil, the intermediate signal corresponding to the input signal, the receive coil being disposed within a receiver die; coupling the intermediate signal to receiver circuitry disposed within the receiver die; converting the intermediate signal to a DC voltage using a power conversion circuit disposed within the receiver die; generating a switch drive signal from the DC voltage using a driver circuit disposed within the receiver die; transitioning the solid-state switch from an OFF state to an ON state in response to the solid-state switch receiving the switch drive signal; and shielding electromagnetic noise generated by the receive coil from the receiver circuitry via a shield positioned between the receive coil and the receiver circuitry. 2. The method of claim 1, wherein the solid-state switch includes a first transistor having a first gate, a first source, and a first drain; the solid-state switch further includes a second transistor having a second gate, a second source, and a second drain, the first source connected to the second source to form a bidirectional switch, and the first gate and the second gate arranged to receive a switch drive signal. 3. The method of claim 1, wherein the transmitter die is attached to the receiver die. 4. The method of claim 3, wherein the receiver die is attached to a switch die that includes a solid-state switch. 5. The method of claim 1, wherein the receiving coil is a first receiving coil, the intermediate signal is a first intermediate signal, and the solid-state relay device further comprises a second receiving coil that generates a second intermediate signal in response to coupling the time-varying voltage to the transmitting coil. 6. The method of claim 5, wherein the switch drive signal is a first switch drive signal, the solid-state switch is a first solid-state switch, and the method further comprises generating a second switch drive signal from the DC voltage, the second switch drive signal transitioning the second solid-state switch from an OFF state to an ON state in response to the second solid-state switch receiving the second switch drive signal. 7. The method of claim 1, wherein the input signal corresponds to a DC voltage, and the DC voltage is electrically isolated from the input signal. 8. The method of claim 1, wherein the solid-state relay device further comprises a power storage device, and the power conversion circuit generates the DC voltage using energy stored in the power storage device. 9. The method of claim 1, wherein the transmit die includes a data modulation circuit that couples the data onto a time-varying voltage. 10. The method of claim 1, wherein the receiver circuitry includes a data demodulation circuitry that demodulates data from the intermediate signal. 11. A method of forming a solid state relay, the method comprising: Attaching a receiver die to the switch die, the receiver die including a pair of receiver input terminals, a pair of output terminals, and a coupler region, the coupler region including: A transmitting coil; a receiver coil positioned adjacent to the transmitter coil and connected to a pair of output terminals; a receiver circuit connected to the receiver coil; a shielding layer positioned between the receiver circuit and the receiver coil; attaching a transmitter die to a receiver die, the transmitter die including a pair of input terminals coupled to a pair of transmitter output terminals; forming one or more electrical connections between the transmitter die and the receiver die such that the transmitter coil is connected to a pair of transmitter output terminals; forming one or more electrical connections between the switch die and the receiver die such that the receiver circuitry is coupled to a solid-state switch disposed on the switch die; and at least partially encapsulating the receiver die, the switch die, and the transmit die in an electrically insulating material. 12. The method of claim 11, wherein the transmitter die includes a transmitter circuit arranged to generate a time-varying voltage in response to receiving an input signal at the input terminal. 13. The method of claim 12, wherein a time-varying voltage is coupled to the transmitter coil, and in response to receiving the time-varying voltage, the transmitter coil induces the receiver coil to generate an intermediate signal corresponding to the input signal. 14. The method of claim 13, wherein the solid-state relay further comprises a power storage device coupled to the receiver circuit, the receiver circuit configured to generate a DC signal in the power storage device in response to generation of the intermediate signal. 15. The method of claim 13, wherein the receiver circuit generates a DC voltage in response to generating the intermediate signal. 16. The method of claim 15, wherein the DC voltage is a first DC voltage, and the receiver circuit generates a second DC voltage in response to the generation of the intermediate signal, the second DC voltage being higher than the first DC voltage. 17. A method of operating a solid-state relay device, the method comprising: receiving an input signal at an input of a solid state relay device; coupling the input signal to a transmit circuit disposed on the transmit die, the transmit circuit generating a corresponding time-varying voltage in response to receiving the input signal; coupling a time-varying voltage from a transmit circuit to a transmit coil disposed in a separate receiver die; inducing a receive coil to generate an intermediate signal in response to coupling a time-varying voltage to the transmit coil, the intermediate signal corresponding to the input signal, the receive coil being disposed within a receiver die; coupling the intermediate signal to receiver circuitry disposed within the receiver die; generating a switch drive signal in response to coupling the intermediate signal to the receiver circuit; transitioning the solid-state switch from an OFF state to an ON state in response to the solid-state switch receiving the switch drive signal; A method in which the switch drive signal corresponds to the input signal, and the drive signal is electrically isolated from the input signal. 18. The method of claim 17, further comprising shielding electromagnetic noise generated by the receive coil from the receiver circuitry via a shield positioned between the receive coil and the receiver circuitry. 19. The method of claim 17, wherein the solid-state switch is a bidirectional switch having a first gate and a second gate that receive a drive signal. 20. The method of claim 19, wherein the method further comprises generating an auxiliary DC voltage in response to coupling the intermediate signal to a receiver circuit.

[0072] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that the claimed subject matter may be practiced without these specific details. In other instances, methods and apparatuses that would be known to those skilled in the art have not been described in detail so as not to obscure the claimed subject matter. Therefore, it is not intended that the claimed subject matter be limited to the particular examples disclosed, but rather that such claimed subject matter also include all aspects within the scope of the appended claims and equivalents thereof.

Claims

1. 1. A signal isolation device comprising: a transmitter die including a pair of input terminals coupled to a pair of transmitter output terminals; a receiver die including a pair of receiver input terminals, a pair of output terminals, and a coupler region, the transmitter die being attached to a top surface of the receiver die, the coupler region including: a transmitting coil connected to the pair of transmitter output terminals; a receiver coil positioned adjacent to the transmitter coil and connected to the pair of output terminals; a receiver circuit; a shielding layer positioned between the receiver circuit and the receiver coil.

2. 10. The signal isolation device of claim 1, wherein the transmitter die includes a signal generator that generates a time-varying voltage at the pair of transmitter output terminals in response to receiving an input signal at the pair of input terminals.

3. 3. The signal isolation device of claim 2, wherein the time-varying voltage is coupled to the transmitter coil, and wherein, in response to receiving the time-varying voltage, the transmitter coil induces the receiver coil to generate an intermediate signal corresponding to the input signal.

4. 4. The signal isolation device of claim 3, wherein the receiver die includes a power conversion circuit, the power conversion circuit receiving the intermediate signal and, in response, the power conversion circuit generating a DC voltage.

5. 5. The signal isolation device of claim 4, wherein the receiver die includes a driver circuit that generates a switch drive signal in response to receiving the DC voltage.

6. 6. The signal isolation device of claim 5, wherein the switch drive signal is coupled to a transistor, the transistor transitioning from an off state to an on state in response to receiving the switch drive signal.

7. 4. The signal isolation device of claim 3, further comprising a power storage device coupled to a control circuit, the control circuit being positioned to receive the intermediate signal, and in response to receiving the intermediate signal, the control circuit causing the power storage device to generate a DC signal.

8. 4. The signal isolation device of claim 3, wherein the receiver die includes a power conversion circuit disposed to receive the intermediate signal, and wherein, in response to receiving the intermediate signal, the power conversion circuit generates a first DC signal at a first voltage and a second DC signal at a second voltage, the first voltage being higher than the second voltage.

9. 4. The signal isolation device of claim 3, wherein the receiver circuitry includes data communications circuitry that demodulates a data signal from the intermediate signal.

10. 10. The signal isolation device of claim 1, further comprising an encapsulant at least partially encapsulating the transmitter die and the receiver die.

11. 1. A signal isolation device comprising: a transmit die including an input coupled to a transmitter output; a receiver die including a receiver input, an output, and a coupler area, the receiver input being connected to the transmitter output, the coupler area including: a transmit coil connected to the receiver input; a receiver coil connected to the output; a receiver circuit; a shield positioned between the receiver circuit and the receiver coil.

12. 12. The signal isolation device of claim 11, wherein the transmitter die includes a signal generator that generates a time-varying voltage at the transmitter output in response to receiving an input signal at the input.

13. 13. The signal isolation device of claim 12, wherein the time-varying voltage is coupled to the transmitter coil, and wherein, in response to receiving the time-varying voltage, the transmitter coil induces the receiver coil to generate an intermediate signal corresponding to the input signal.

14. 14. The signal isolation device of claim 13, wherein the receiver die includes a power conversion circuit disposed to receive the intermediate signal, the power conversion circuit generating a DC signal in response to receiving the intermediate signal.

15. 15. The signal isolation device of claim 14, wherein the receiver die includes a driver circuit that receives the DC signal, and wherein the driver circuit generates a switch drive signal in response to receiving the DC signal.

16. 16. The signal isolation device of claim 15 configured to couple the switch drive signal to a transistor, the transistor transitioning from an off state to an on state in response to receiving the switch drive signal.

17. 14. The signal isolation device of claim 13, further comprising a power storage device coupled to a control circuit, the control circuit receiving the intermediate signal and, in response, causing the power storage device to generate a DC signal.

18. 14. The signal isolation device of claim 13, wherein the receiver die includes power conversion circuitry arranged to receive the intermediate signal, and wherein, in response to receiving the intermediate signal, the power conversion circuitry generates a first DC signal at a first voltage and a second DC signal at a second voltage, the first voltage being higher than the second voltage.

19. 14. The signal isolation device of claim 13, wherein the receiver circuitry includes data communications circuitry that demodulates a data signal from the intermediate signal.

20. 12. The signal isolation device of claim 11, further comprising an encapsulant at least partially encapsulating the transmitter die and the receiver die.

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