Optoemulator

Abstract

The opto-emulator transmitter (102A) includes a current controller (222), an oscillator circuit (238), and a receiver replica circuit element (258). The current controller has a first terminal (224), a second terminal (228), and a third terminal (230). The oscillator circuit has a first terminal (240), a second terminal (242), and a third terminal (244). The first terminal (240) of the oscillator circuit is coupled to the second terminal (228) of the current controller. The receiver replica circuit element has a first terminal (260), a second terminal (262), and a third terminal (264). The first terminal (260) of the receiver replica circuit element is coupled to the second terminal (242) of the oscillator circuit. The second terminal (262) of the receiver replica circuit element is coupled to the third terminal (244) of the oscillator circuit. The third terminal of the receiver replica circuit element (258) is connected to the third terminal of the current controller.

Description

[Technical Field]

[0001] An optocoupler is an isolation device containing a light-emitting component and a photosensitive component, used to transmit a signal while blocking the ground potential difference (GPD) between them. The light-emitting component can be a light-emitting diode (LED), and the photosensitive component is usually a phototransistor or photodiode. The light-emitting and photosensitive components are physically separated by distance and insulating material. In an optocoupler, the output current (I C ) is the input current (I F It is proportional to ). Over time, signal transmission via the optocoupler deteriorates due to the aging of the light-emitting component, clouding of the insulating material, and / or other aging problems. C / I F The ratio can change over time.

[0002] Opto-emulators can offer the same isolated communication behavior as optocouplers, along with advantages such as improved speed, isolation, operating temperature range, and aging characteristics. However, opto-emulators still have limitations. C / I F There are several problems, including the nonlinearity of the ratio. [Overview of the Initiative]

[0003] In one example, the opto-emulator transmitter includes a current controller, an oscillator circuit, and a receiver replica circuit element. The current controller has a first terminal, a second terminal, and a third terminal. The oscillator circuit has a first terminal, a second terminal, and a third terminal. The first terminal of the oscillator circuit is coupled to the second terminal of the current controller. The receiver replica circuit element has a first terminal, a second terminal, and a third terminal. The first terminal of the receiver replica circuit element is coupled to the second terminal of the oscillator circuit. The second terminal of the receiver replica circuit element is coupled to the third terminal of the oscillator circuit. The third terminal of the receiver replica circuit element is coupled to the third terminal of the current controller.

[0004] In another example, the opto-emulator transmitter includes a transmitter circuit element having a first terminal, a second terminal, a third terminal, a fourth terminal, and a fifth terminal, and a receiver replica circuit element having a first terminal, a second terminal, and a third terminal. The first terminal of the receiver replica circuit element is coupled to the third terminal of the transmitter circuit element. The second terminal of the receiver replica circuit element is coupled to the fourth terminal of the transmitter circuit element. The third terminal of the receiver replica circuit element is coupled to the fifth terminal of the transmitter circuit element. The transmitter circuit element is configured to receive current at the first terminal of the transmitter circuit element, provide a transmit signal at the third and fourth terminals of the transmitter circuit element in response to the current, receive a feedback signal from the receiver replica circuit element at the fifth terminal of the transmitter circuit element in response to the transmit signal, and provide a tuned transmit signal at the third and fourth terminals of the transmitter circuit element in response to the current and the feedback signal.

[0005] In yet another example, the opto-emulator circuit includes a receiver die and a transmitter die. The receiver die includes a first rectifier circuit having a first terminal, a second terminal, and a third terminal, and a first transistor having a first terminal, a second terminal, and a control terminal, the control terminal of the transistor being coupled to the third terminal of the rectifier circuit. The transmitter die includes a current controller, an oscillator circuit, a second rectifier circuit, and a second transistor. The current controller has a first terminal, a second terminal, and a third terminal. The oscillator circuit has a first terminal, a second terminal, and a third terminal. The first terminal of the oscillator circuit is coupled to the second terminal of the current controller. The second rectifier circuit has a first terminal, a second terminal, and a third terminal. The first terminal of the second rectifier circuit is coupled to the second terminal of the oscillator circuit. The second terminal of the second rectifier circuit is coupled to the third terminal of the oscillator circuit. The second transistor has a first terminal, a second terminal, and a control terminal. The control terminal of the transistor is coupled to the third terminal of the second rectifier circuit. [Brief explanation of the drawing]

[0006] [Figure 1]It is a block diagram illustrating an example system.

[0007] [Figure 2] It is a diagram illustrating an example opto-emulator transmitter.

[0008] [Figure 3] It is a diagram illustrating an example opto-emulator receiver.

[0009] [Figure 4] It is a diagram illustrating an example opto-emulator.

[0010] [Figure 5] It is a diagram illustrating another example opto-emulator transmitter.

[0011] [Figure 6] It is a diagram illustrating an example wafer for an opto-emulator. MODES FOR CARRYING OUT THE INVENTION

[0012] In the drawings, the same reference numerals or other reference identifiers are used to indicate the same or similar features. Such features may be functionally and / or structurally the same or similar.

[0013] Described herein is a topology for an analog opto-emulator. As used herein, an "opto-emulator" includes the same input terminals and output terminals as an optocoupler, and emulates the behavior of an optocoupler without a light-emitting component and a light-receiving component (input current (I F ) proportional output current (I C ) refers to a circuit that provides. The topology of the described analog opto-emulator provides a wide range of I C values and I F current transfer ratio (CTR, where CTR=I C / I FThis provides advantages such as improved linearity, and improved resistance and insulation rating.

[0014] Figure 1 is a block diagram illustrating an exemplary system 100. As shown, the system 100 includes a sensor 170, an opto-emulator transmitter 102, an isolation circuit element 134, an opto-emulator receiver 150, a controller 176, an auxiliary circuit 186, and an electromechanical device 190. The sensor 170 has a first terminal 172 and a second terminal 174. The opto-emulator transmitter 102 has a first terminal 104, a second terminal 106, a third terminal 108, and a fourth terminal 110. The isolation circuit element 134 has a first terminal 136, a second terminal 138, a third terminal 140, and a fourth terminal 142. The opto-emulator receiver 150 has a first terminal 152, a second terminal 154, a third terminal 156, and a fourth terminal 158. The controller 176 has a first terminal 178, a second terminal 180, a third terminal 182, and a fourth terminal 184. The auxiliary circuit element 186 has terminal 188. The electromechanical device 190 has terminal 192.

[0015] In the example in Figure 1, the opto-emulator transmitter 102 includes a transmitter circuit element 112 and a receiver replica circuit element 126. The transmitter circuit element 112 has a first terminal 114, a second terminal 116, a third terminal 118, a fourth terminal 120, and a fifth terminal 122. As shown, the transmitter circuit element 112 includes a feedback control circuit element 124. The receiver replica circuit element 126 has a first terminal 128, a second terminal 130, and a third terminal 132. The opto-emulator transmitter 102 also includes a receiver circuit element 160. The receiver circuit element 160 has a first terminal 162, a second terminal 164, a third terminal 166, and a fourth terminal 168.

[0016] The first terminal 104 of the opto-emulator transmitter 102 is connected to the first terminal 172 of the sensor 170. The second terminal 106 of the opto-emulator transmitter 102 is connected to the second terminal 174 of the sensor 170. The third terminal 108 of the opto-emulator transmitter 102 is connected to the first terminal 136 of the isolation circuit element 134. The fourth terminal 110 of the opto-emulator transmitter 102 is connected to the second terminal 138 of the isolation circuit element 134. The third terminal 140 of the isolation circuit element 134 is connected to the first terminal 152 of the opto-emulator receiver 150. The fourth terminal of the isolation circuit element 134 is connected to the second terminal 154 of the opto-emulator receiver 150. The third terminal 156 of the opto-emulator receiver 150 is connected to the first terminal 178 of the controller 176. The fourth terminal 158 of the opto-emulator receiver 150 is connected to the second terminal 180 of the controller 176. The third terminal 182 of the controller 176 is connected to terminal 188 of the auxiliary circuit 186. The fourth terminal 184 of the controller 176 is connected to terminal 192 of the electromechanical device 190.

[0017] The first terminal 114 of the transmitter circuit element 112 is connected to the first terminal 104 of the opto-emulator transmitter 102. The second terminal 116 of the transmitter circuit element 112 is connected to the second terminal 106 of the opto-emulator transmitter 102. The third terminal 118 of the transmitter circuit element 112 is connected to the third terminal 108 of the opto-emulator transmitter 102 and to the first terminal 128 of the receiver replica circuit element 126. The fourth terminal 120 of the transmitter circuit element 112 is connected to the fourth terminal 110 of the opto-emulator transmitter 102 and to the second terminal 130 of the receiver replica circuit element 126. The third terminal 132 of the receiver replica circuit element 126 is connected to the fifth terminal 122 of the transmitter circuit element 112.

[0018] A first terminal 162 of the receiver circuit element 160 is coupled to a first terminal 152 of the opto-emulator receiver 150. A second terminal 164 of the receiver circuit element 160 is coupled to a second terminal 154 of the opto-emulator receiver 150. A third terminal 166 of the receiver circuit element 160 is coupled to a third terminal 156 of the opto-emulator receiver 150. A fourth terminal 168 of the receiver circuit element 160 is coupled to a fourth terminal 158 of the opto-emulator receiver 150.

[0019] In some examples, the sensor 170 operates to sense ambient parameters (e.g., voltage, current, temperature, magnetic field, motion, vibration, etc.) and provide current or current modulation at a first terminal 172 in response to the sensed ambient parameters. The opto-emulator transmitter 102 operates to receive current or current modulation at a first terminal 104, prepare a transmission signal in response to the received current or current modulation, the operation of the transmitter circuit element 112, and the operation of the receiver replica circuit element 126, and provide the transmission signal to a third terminal 108 and / or a fourth terminal 110. During operation of the opto-emulator transmitter 102, current may flow from the first terminal 104, through the transmitter circuit element 112 and / or the receiver replica circuit element 126, to the second terminal 106. The second terminal 106 may be coupled to ground or a ground terminal (not shown).

[0020] In some examples, transmitter circuit 112 receives a current or current modulation at first terminal 114, and operates to provide a transmission signal at third terminal 118 and fourth terminal 120 in response to the received current or current modulation and the operation of transmitter circuit 112. Receiver replica circuit 126 receives the transmission signal at first terminal 128 and second terminal 130, and operates to provide a feedback signal at third terminal 132 in response to the transmission signal and the operation of receiver replica circuit 126. Over time, transmitter circuit 112 also receives the feedback signal at fifth terminal 122, and operates to adjust the transmission signal based on the feedback signal and the operation of feedback control circuit 124. In some examples, the optical emulator transmitter 102 receives an input current of 0.5 mA to 5 mA, and provides a transmission signal having a differential input amplitude of 0.7 V to 1.4 V.

[0021] In some examples, isolation circuit 134 receives the transmission signal at first terminal 136 and second terminal 138, and operates to provide an isolated transmission signal at third terminal 140 and fourth terminal 142. In some examples, isolation circuit 134 comprises a transformer. As another example, isolation circuit 134 may comprise a capacitive isolation circuit. In some examples, the isolated transmission signal is attenuated relative to the transmission signal. Also, the isolated transmission signal may remove a common-mode signal or other characteristics of the transmission signal. In some examples, transmitter circuit 112 receives a transmission signal having a differential input amplitude of 0.7 V to 1.4 V, and provides an isolated transmission signal comprising a differential switch of 0.5 V to 1.05 V.

[0022] In some examples, the opto-emulator receiver 150 receives an isolated transmit signal at a first terminal 152 and a second terminal 154, and operates to provide opto-emulator results at a third terminal 156 and a fourth terminal 158 based on the isolated transmit signal and the operation of the receiver circuit element 160. In some examples, the opto-emulator receiver 150 receives an isolated transmit signal having a differential input amplitude of 0.7V to 1.4V and provides an output current proportional to the input current. The output current may be, but is not limited to, 130%, 180%, 300%, or 440% greater than the input current. In such examples, the respective CTRs are 1.3, 1.8, 3.0, or 4.4.

[0023] Controller 176 receives opto-emulator results at first terminal 178 and second terminal 180, processes the opto-emulator results as part of a feedback-based control operation, provides a first control signal at third terminal 182 in response to the feedback-based control operation, and provides a second control signal at fourth terminal 184 in response to the feedback-based control operation. Auxiliary circuit 186 receives a first control signal at terminal 188 and operates to adjust auxiliary operation in response to the first control signal. In some examples, auxiliary circuit 186 is a display controller, and the auxiliary operation adjusts the information to be displayed using the display controller. Electromechanical device 190 receives a second control signal at terminal 192 and operates to adjust the operation of electromechanical device 190 in response to the second control signal. In some examples, electromechanical device 190 is a motor, and the second control signal adjusts the speed and / or torque of the motor. In another example, electromechanical device 190 is an actuator, and the second control signal adjusts the position of the actuator.

[0024] Figure 2 shows an illustrative opto-emulator transmitter 102A. Opto-emulator transmitter 102A is an example of the opto-emulator transmitter 102 shown in Figure 1. Opto-emulator transmitter 102A includes a first terminal 104, a second terminal 106, a third terminal 108, and a fourth terminal 110, as described in Figure 1. Using optocoupler terminology, the first terminal 104 may be called the anode terminal, and the second terminal 106 may be called the cathode terminal. Opto-emulator transmitter 102A also has a fifth terminal 202.

[0025] In the example in Figure 2, the opto-emulator transmitter 102A includes a fuse 204, a reverse protection circuit element 210, an electrostatic discharge (ESD) circuit element 216, a current controller 222, a diode emulator 232, an inductor-capacitor (LC) oscillator 238, an attenuator circuit 248, a differential rectifier circuit 258, and a transistor M1, in the arrangement shown. Comparing Figure 2 with Figure 1, the fuse 204, the reverse protection circuit element 210, the ESD circuit element 216, the current controller 222, the diode emulator 232, and the LC oscillator 238 are exemplary components of the transmitter circuit element 112 in Figure 1. The current controller 222 and the diode emulator 232 are exemplary components of the feedback control circuit element 124. The differential rectifier circuit 258 and the transistor M1 are exemplary components of the receiver replica circuit element 126.

[0026] As shown in the figure, the fuse 204 has a first terminal 206 and a second terminal 208. The reverse protection circuit element 210 has a first terminal 212 and a second terminal 214. The ESD circuit element 216 has a first terminal 218 and a second terminal 220. The current controller 222 has a first terminal 224, a second terminal 226, a third terminal 228, and a fourth terminal 230. The diode emulator 232 has a first terminal 234 and a second terminal 236. The LC oscillator 238 has a first terminal 240, a second terminal 242, a third terminal 244, and a fourth terminal 246. The attenuator circuit 248 has a first terminal 250, a second terminal 252, a third terminal 254, and a fourth terminal 256. The differential rectifier circuit 258 has a first terminal 260, a second terminal 262, and a third terminal 264. Transistor M1 has a first terminal, a second terminal, and a control terminal.

[0027] The first terminal 206 of fuse 204 is connected to the first terminal 104 of opto-emulator transmitter 102A. The second terminal 208 of fuse 204 is connected to the first terminal 212 of reverse protection circuit element 210 and the first terminal 218 of ESD circuit element 216. The second terminal of ESD circuit element 216 is connected to the second terminal 106 of opto-emulator transmitter 102A. The second terminal 214 of reverse protection circuit element 210 is connected to the first terminal 224 of current controller 222. The second terminal 226 of current controller 222 is connected to the first terminal 234 of diode emulator 232. The second terminal 236 of diode emulator 232 is connected to the second terminal 106 of opto-emulator transmitter 102A. The third terminal 228 of current controller 222 is connected to the first terminal 240 of LC oscillator 238. The fourth terminal 230 of the current controller is coupled to the first terminal of transistor M1. The second terminal 242 of the LC oscillator 238 is coupled to the third terminal 108 of the opto-emulator transmitter 102A and the first terminal 250 of the attenuator circuit 248. The third terminal 244 of the LC oscillator 238 is coupled to the fourth terminal 110 of the opto-emulator transmitter 102A and the second terminal 252 of the attenuator circuit 148. The fourth terminal 246 of the LC oscillator 238 is coupled to the fifth terminal 202 of the opto-emulator transmitter 102A. The third terminal 254 of the attenuator circuit 248 is coupled to the first terminal 260 of the differential rectifier circuit 258. The fourth terminal 256 of the attenuator circuit 248 is coupled to the second terminal 262 of the differential rectifier circuit 258. The third terminal 264 of the differential rectifier circuit 258 is coupled to the control terminal of transistor M1. The second terminal of transistor M1 is coupled to the second terminal 106 of the opto-emulator transmitter 102A.

[0028] In some examples, the opto-emulator transmitter 102A receives current or current modulation at a first terminal 104 (e.g., from a sensor such as sensor 170 in Figure 1), and operates to prepare a transmit signal in response to the received current or current modulation, the operation of transmitter circuit elements (e.g., fuse 204, reverse protection circuit element 210, ESD circuit element 216, current controller 222, diode emulator 232, and LC oscillator 238), and the operation of receiver replica circuit elements (e.g., differential rectifier circuit 258 and transistor M1), and provides the transmit signal to a third terminal 108 and / or a fourth terminal 110. During the operation of the opto-emulator transmitter 102A, current may flow from the first terminal 104 through the transmitter circuit elements and / or receiver replica circuit element 126 to the second terminal 106. The second terminal 106 may be connected to ground or a ground terminal (not shown).

[0029] In some examples, fuse 204 receives current at a first terminal 206 and operates to transfer the current to a second terminal 208 if the received current is less than a threshold, and to create an open circuit if the received current is equal to or greater than the threshold. Reverse protection circuit element 210 receives current at a first terminal 212 and, in response to the current having a forward direction 215, operates to transfer the received current to a second terminal 214 to prevent current from flowing in the opposite direction (reverse direction) to the forward direction 215. ESD circuit element 216 receives ESD voltage and / or ESD current at a first terminal 218 and operates to keep the ESD voltage below a threshold and discharge the ESD current to ground (for example, by selectively connecting the first terminal 218 to the second terminal 220 when the ESD current exceeds a threshold).

[0030] The current controller 222 receives a regulated (e.g., clamped) current at the first terminal 224, provides a first current to the diode emulator 232 in response to the regulated current, generates an input voltage (VF) between the first terminal 104 and the second terminal 106 of the opto-emulator transmitter 102A, where VF is based on the input current (IF), provides a second current to the LC oscillator 238 in response to the regulated current, provides a third current to the transistor M1 in response to the regulated current, compares the third current to a reduced version of the second current to obtain a comparison result, and adjusts the second current in response to the comparison result. In some examples, the current controller 222 includes reliability clamp circuit elements (e.g., reliability clamp circuit element 502 in Figure 5), shunt bypass circuit elements (e.g., shunt bypass circuit element 504 in Figure 5), source follower circuit elements (e.g., source follower circuit element 506 in Figure 5), current mirror circuit elements (e.g., current mirror circuit element 508 in Figure 5), and / or current comparator circuit elements (e.g., current comparator circuit element 510 in Figure 5).

[0031] The diode emulator 232 operates to generate a forward voltage (VF) between the first terminal 104 and the second terminal 106 in response to the input current. In some examples, the diode emulator 232 includes a VF bias circuit element (e.g., the VF bias circuit element 512 in Figure 5).

[0032] The LC oscillator 238 receives a voltage at the first terminal 240 that is VF or based on VF (for example, proportional to VF), receives a second current from the current controller 222 at the first terminal 240, and operates to provide a transmit signal at the second terminal 242 and the third terminal 244 in response to the received voltage and current. In some examples, the transmit signal is a differential signal to a fourth terminal 246 that may be connected to ground or a ground terminal. The attenuator circuit 248 receives the transmit signal at the first terminal 250 and the second terminal 252, and operates to provide an attenuated transmit signal at the third terminal 254 and the fourth terminal 256. The differential rectifier circuit 258 receives the attenuated transmit signal at the first terminal 260 and the second terminal 262, and operates to provide a rectified signal at the third terminal 264 in response to the attenuated transmit signal. Transistor M1 receives the rectified signal at its control terminal and operates to selectively allow current to flow from the first terminal to the second terminal of transistor M1 in response to the rectified signal.

[0033] Figure 3 shows an example of an opto-emulator receiver 150A. The opto-emulator receiver 150A is an example of the opto-emulator receiver 150 in Figure 1. The opto-emulator receiver 150A has a first terminal 152, a second terminal 154, a third terminal 156, and a fourth terminal 158 as described in Figure 1. Using the term optocoupler, the third terminal 156 may be called the collector terminal, and the fourth terminal 158 may be called the emitter terminal. The opto-emulator receiver 150A also has a fifth terminal 302.

[0034] In the example shown in Figure 3, the opto-emulator receiver 150A includes a differential rectifier circuit 304, transistors M2 and M3, and an ESD circuit element 314 in the arrangement shown. Comparing Figure 3 with Figure 1, the differential rectifier circuit 304 and transistor M2 are illustrative components of the receiver circuit element 160 in Figure 1. The differential rectifier circuit 304 has a first terminal 306, a second terminal 308, a third terminal 310, and a fourth terminal 312. Each of the transistors M2 and M3 has its own first terminal, its own second terminal, and its own control terminal. The ESD circuit element 314 has its first terminal and its second terminal.

[0035] The first terminal 306 of the differential rectifier circuit 304 is coupled to the first terminal 152 of the opto-emulator receiver 150A. The second terminal 308 of the differential rectifier circuit 304 is coupled to the second terminal 154 of the opto-emulator receiver 150A. The third terminal 310 of the differential rectifier circuit 304 is coupled to the fifth terminal 302 of the opto-emulator receiver 150A. The fourth terminal of the differential rectifier circuit 304 is coupled to the control terminals of transistors M2 and M3. The first terminal of transistor M2 is coupled to the third terminal 156 of the opto-emulator receiver 150A and the first terminal 316 of the ESD circuit element 314. The second terminal of transistor M2 is coupled to the first terminal of transistor M3. The second terminal of transistor M3 is coupled to the fourth terminal 158 of the opto-emulator receiver 150A and the second terminal 318 of the ESD circuit element 314. In some examples, transistor M2 may be replicated with parallel copies having each first terminal selectively coupled together and / or each control terminal selectively coupled together, providing an adjustable CTR value as a manufacturing option or a post-manufacturing control option.

[0036] In the example in Figure 3, transistor M2 acts as a current that controls the transistor in the forward direction (current flows from the third terminal 156 to the fourth terminal 158). Transistor M3 acts as an ON switch in the forward direction (current flows from the third terminal 156 to the fourth terminal 158) and as an OFF switch in the reverse direction (blocking the flow of current from the fourth terminal 158 to the third terminal 156). In some examples, transistor M1 is a replica of transistor M2, and a replica of transistor M3 is not used.

[0037] In some examples, the opto-emulator receiver 150 receives an isolated transmit signal at a first terminal 152 and a second terminal 154, and operates to provide opto-emulator results at a third terminal 156 and a fourth terminal 158 in response to the isolated transmit signal and the operation of receiver circuit elements (e.g., a differential rectifier circuit 304 and transistor M2). In some examples, the isolated transmit signal is a differential signal, and the isolated transmit signal is received at the first terminal 152 and the second terminal 154 with reference to a fifth terminal 302 which may be coupled to ground or a ground terminal (not shown).

[0038] The differential rectifier circuit 304 receives an isolated transmit signal at the first terminal 306 and the second terminal 308 with reference to a third terminal 310 which may be coupled to ground or a ground terminal (not shown), and operates to provide a rectified signal at the fourth terminal 312 in response to the isolated transmit signal. Transistor M2 receives the rectified signal at its control terminal and operates to allow current to flow between the first and second terminals in response to the rectified signal. Transistor M3 receives the rectified signal at its control terminal and operates to allow current to flow between its first and second terminals in response to the rectified signal. The ESD circuit element 314 receives the ESD voltage and / or ESD current at the first terminal 316, maintains the ESD voltage below a threshold, and, when the ESD current exceeds the threshold, operates to discharge the ESD current to ground (for example, by selectively connecting the first terminal 316 to the second terminal 318). When using the opto-emulator receiver 150A, the isolated transmitted signal is converted into a modulated current at the third terminal 156 and the fourth terminal 158. When the output of the differential rectifier circuit 304 is low, the opto-emulator result (i.e., output current) is low. When the output of the differential rectifier circuit 304 is high, the opto-emulator result (i.e., output current) is high. In other words, the output current from the opto-emulator receiver 150A is proportional to the input current to the opto-emulator transmitter.

[0039] Figure 4 shows an exemplary opto-emulator 400. In the example of Figure 4, the opto-emulator 400 includes the opto-emulator transmitter 102A of Figure 2, the isolation circuit element 134A, and the opto-emulator receiver 150A of Figure 3. The isolation circuit element 134A is an example of the isolation circuit element 134 of Figure 1. In the example of Figure 4, the opto-emulator transmitter 102A has the same terminals and components as in Figure 2, and the opto-emulator receiver 150A has the same terminals and components as in Figure 3. The isolation circuit element 134A has the first terminal 136, the second terminal 138, the third terminal 140, and the fourth terminal 142 as described in Figure 1. The isolation circuit element 134A also has a fifth terminal 402 and a sixth terminal 404.

[0040] In the example shown in Figure 4, the opto-emulator transmitter 102A, the isolation circuit element 134A, and the opto-emulator receiver 150A are separate integrated circuit (IC) dies. In some examples, these separate IC dies may be packaged together as a multi-chip module (MCM).

[0041] In the example in Figure 4, the isolation circuit element 134A includes a transformer circuit element 406. The transformer circuit element 406 is an example of a single transformer having center taps on both the input and output sides. As shown, the transformer circuit element 406 includes a first coil L1, a second coil L2, a third coil L3, and a fourth coil L4. The first coil L1 has a first terminal and a second terminal. The second coil L2 has a first terminal and a second terminal. The third coil L3 has a first terminal and a second terminal. The fourth coil L4 has a first terminal and a second terminal. The first terminal of the first coil L1 is coupled to the first terminal 136 of the isolation circuit element 134A. The second terminal of the first coil L1 is coupled to the fifth terminal 402 of the isolation circuit element 134A and the first terminal of the second coil L2. The second terminal of the second coil L2 is connected to the second terminal 138 of the isolation circuit element 134A. The first terminal of the third coil L3 is connected to the third terminal 140 of the isolation circuit element 134A. The second terminal of the third coil L3 is connected to the sixth terminal 404 of the isolation circuit element 134A and the first terminal of the fourth coil L4. The second terminal of the fourth coil L4 is connected to the fourth terminal 142 of the isolation circuit element 134A.

[0042] In the example in Figure 4, the opto-emulator transmitter 102A performs the operation described in Figure 2, the isolation circuit element 134A performs the operation described for the isolation circuit element 134 in Figure 1, and the opto-emulator receiver 150A performs the operation described in Figure 3. Using the isolation circuit element 134A, the transmitted signals received at the first terminal 136 and the second terminal 138 are referenced to a fifth terminal 402 which may be coupled to ground or a ground terminal (not shown). In addition, the isolated transmitted signals provided at the third terminal 140 and the fourth terminal 142 are referenced to a sixth terminal 404 which may be coupled to ground or a ground terminal (not shown). In other examples, the isolation circuit element 134A may include a capacitive isolation circuit element instead of the transformer circuit element 406.

[0043] Figure 5 shows an example of an opto-emulator transmitter 102B. Opto-emulator transmitter 102B is an example of an opto-emulator transmitter 102B. Opto-emulator transmitter 102B is an example of an opto-emulator transmitter 102 in Figure 1 or an opto-emulator transmitter 102A in Figure 2. As shown, the opto-emulator transmitter 102B has a first terminal 104, a second terminal 106, a third terminal 108, and a fourth terminal 110, as described in Figures 1 and 2.

[0044] In the example in Figure 5, the opto-emulator transmitter 102B includes a reliability clamp circuit element 502, a shunt bypass circuit element 504, a source follower circuit element 506, a current mirror circuit element 508, a current comparator circuit element 510, a VF bias circuit element 512, a transistor M19, an LC oscillator 238, an attenuator circuit 248, and a differential rectifier circuit 258. Comparing the opto-emulator transmitter 102B with the opto-emulator transmitter 102A in Figure 2, the reliability clamp circuit element 502, the shunt bypass circuit element 504, the source follower circuit element 506, the current mirror circuit element 508, the current comparator circuit element 510, and the VF bias circuit element 512 are exemplary components of the current controller 222 and diode emulator 232 in Figure 2.

[0045] As shown in the figure, the reliability clamp circuit element 502 includes resistors R1 and R2, transistor M4, diodes D1 to D4, and capacitor C1 in the arrangement shown. The shunt bypass circuit element 504 includes transistors M5 and M6 in the arrangement shown. The source follower circuit element 506 includes transistors M7 and M8 in the arrangement shown. The current mirror circuit element 508 includes transistors M9 to M12 in the arrangement shown. The current comparator circuit element 510 includes transistors M1, M13 and M14, and capacitor C2 in the arrangement shown. The VF bias circuit element 512 includes transistors M15 to M8 in the arrangement shown. In the example in Figure 5, each of resistors R1 and R2 has its own first terminal and its own second terminal. Each of capacitors C1 and C2 has its own first terminal and its own second terminal. Each of the diodes D1 to D4 has its own first terminal and its own second terminal. Each of the transistors M4 to M19 has its own first terminal, its own second terminal, and its own control terminal.

[0046] With respect to the reliability clamp circuit element 502, the first terminal of resistor R1 and the first terminal of diode D1 are coupled to the first terminal 104 of opto-emulator transmitter 102B. The second terminal of resistor R1 is coupled to the first terminal of transistor M4. The second terminal of transistor M4 is coupled to the second terminal 106 of opto-emulator transmitter 102B. The second terminal of diode D1 is coupled to the first terminal of diode D2. The second terminal of diode D2 is coupled to the control terminal of transistor M4, the first terminal of capacitor C1, the first terminal of diode D3, and the first terminal of resistor R2. The second terminal of capacitor C1 is coupled to the second terminal 106 of opto-emulator transmitter 102B. The second terminal of diode D3 is coupled to the first terminal of diode D4. The second terminal of diode D4 is coupled to the second terminal 106 of opto-emulator transmitter 102B. The second terminal of resistor R2 is connected to the second terminal 106 of opto-emulator transmitter 102B.

[0047] With respect to the shunt bypass circuit element 504, the first terminal of transistor M5 is coupled to the first terminal 104 of opto-emulator transmitter 102B. The second terminal of transistor M5 is coupled to the first terminal of transistor M6 and to the control terminal of transistor M6. The second terminal of transistor M6 is coupled to the second terminal 106 of opto-emulator transmitter 102B.

[0048] With respect to the source follower circuit element 506, the first terminal of transistor M7 is coupled to the first terminal 104 of the opto-emulator transmitter 102B. The second terminal of transistor M7 is coupled to the first terminal of transistor M8 and the control terminal of transistor M5. The second terminal of transistor M8 is coupled to the second terminal 106 of the opto-emulator transmitter 102B. The control terminal of transistor M8 is coupled to the third terminal 264 of the differential rectifier circuit 258.

[0049] With respect to the current mirror circuit element 508, the first terminals of transistors M9 and M10 are coupled to the first terminal 104 of the opto-emulator transmitter 102B. The second terminal of transistor M9 is coupled to the first terminal of transistor M11 and to the control terminals of transistors M11 and M12. The control terminal of transistor M9 is coupled to the control terminal of transistor M5. The second terminal of transistor M11 is coupled to the second terminal 106 of the opto-emulator transmitter 102B. The second terminal and control terminal of transistor M10 are coupled to the first terminal of transistor M12. The second terminal of transistor M12 is coupled to the second terminal 106 of the opto-emulator transmitter 102B.

[0050] With respect to the current comparator circuit element 510, the first terminals of transistors M13 and M14 are coupled to the first terminal 104 of the opto-emulator transmitter 102B. The second terminal of transistor M13 is coupled to the first terminal of transistor M1, the control terminal of transistor M7, the second terminal of transistor M14, and the first terminal of capacitor C2. The control terminal of transistor M13 is coupled to the control terminal of transistor M10. The second terminal of transistor M1 is coupled to the second terminal 106 of the opto-emulator transmitter 102B. The second terminal of capacitor C2 and the control terminal of transistor M1 are coupled to the third terminal 264 of the differential rectifier circuit 258.

[0051] With respect to the VF bias circuit element 512, the first terminal of transistor M15 is coupled to the first terminal 104 of the opto-emulator transmitter 102B. The second terminal and control terminal of transistor M15 are coupled to the first terminals of transistors M16 and M17, and to the control terminals of transistors M17 and M18. The control terminal of transistor M16 is coupled to the third terminal 264 of the differential rectifier circuit 258. The second terminal of transistor M17 is coupled to the first terminal of transistor M18. The second terminals of transistors M16 and M18 are coupled to the second terminal 106 of the opto-emulator transmitter 102B.

[0052] The first terminal of transistor M19 is coupled to the first terminal 104 of opto-emulator transmitter 102B. The second terminal of transistor M19 is coupled to the first terminal 240 of LC oscillator 238. The control terminal of transistor M19 is coupled to the control terminal of transistor M15. The second terminal 242 of LC oscillator 238 is coupled to the third terminal 108 of opto-emulator transmitter 102B. The third terminal 244 of LC oscillator 238 is coupled to the fourth terminal 110 of opto-emulator transmitter 102B. The fourth terminal 246 of LC oscillator is coupled to the second terminal 106 of opto-emulator transmitter 102B. In the example of Figure 5, the second terminal of opto-emulator transmitter 102B is coupled to ground or the ground terminal. The attenuator circuit 248 is coupled to the third terminal 108 and the fourth terminal of opto-emulator transmitter 102B, as shown in Figure 2. The differential rectifier circuit 258 is coupled to the attenuator circuit 248, as shown in Figure 2.

[0053] The reliability clamp circuit element 502 receives an input current or current modulation and operates to clamp the voltage at the first terminal 104 of the opto-emulator transmitter 102B below a target voltage (e.g., 2V) depending on the current level. The clamping function is based on the forward voltages of diodes D1-D4 and sets the current level and current adjustment based on resistor R1, transistor M4, capacitor C1, and resistor R2. The shunt bypass circuit element 504 operates to clamp and bypass excess input current and limit the current to the LC oscillator 238. The source follower circuit element 506 operates to set the gain of the current controller 222. In some examples, the gain is set to 1. The current mirror circuit element 508 operates to mirror the current of the shunt bypass circuit element 504, attenuate the mirrored current by a target coefficient (e.g., 20), and provide the mirrored current to the current comparator circuit element 510. The current comparator circuit element 510 operates to compare the input current attenuated by the target coefficient (the sum of the attenuated shunt bypass current through transistor M13 and the attenuated oscillator current through transistor M14) with the current through transistor M1 (the output current attenuated by the target coefficient). Based on the comparison, the currents in the shunt bypass circuit element 504 and the LC oscillator 238 are adjusted so that the total input current (current through transistor M13 + current through transistor M14) is equal to the scaled output current through transistor M1 in the steady state. The VF bias circuit element 512 operates to generate a VF between the first terminal 104 and the second terminal 106 in response to the input current.

[0054] In the example in Figure 5, the opto-emulator transmitter 102B uses an attenuator circuit 248 to replicate the attenuation by an isolation circuit element (e.g., isolation circuit element 134 in Figure 1 or isolation circuit element 134A in Figure 4), and uses a differential rectifier circuit 258 to replicate the differential rectifier of the opto-emulator receiver (e.g., opto-emulator receiver 150A in Figure 3) (e.g., differential rectifier circuit 304 in Figure 3). The results from the attenuator circuit 248 and the differential rectifier circuit 258 are used as feedback signals to adjust the current to the LC oscillator 238 using a reliability clamp circuit element 502, a shunt bypass circuit element 504, a source follower circuit element 506, a current mirror circuit element 508, a current comparator circuit element 510, and a VF bias circuit element 512. By adjusting the current to the LC oscillator 238 based on feedback signals from the attenuator circuit 248 and the differential rectifier circuit 258, the CTR linearity of the opto-emulator (e.g., opto-emulator 400 in Figure 4) is improved.

[0055] Figure 6 shows an exemplary wafer 600 for an opto-emulator. The wafer 600 includes a plurality of dies 604, which comprise a die region 606. The die region 606 comprises a portion of a die row, which includes a first die 604A, a second die 604B, a third die 604C, and a fourth die 604D. The first die 604A is an opto-emulator transmitter die comprising a receiver replica circuit element 126A. The second die 604B is an opto-emulator receiver die comprising a receiver circuit element 160A. The third die 604C is an opto-emulator transmitter die comprising a receiver replica circuit element 126B. The fourth die 604D is an opto-emulator receiver die comprising a receiver circuit element 160B. Receiver replica circuit elements 126A and 126B are examples of receiver replica circuit elements 126 in Figure 1. Receiver circuit elements 160A and 160B are examples of receiver circuit element 160 in Figure 1.

[0056] In some examples, the receiver replica circuit element 126A of the first die 604A is manufactured in close proximity to the receiver circuit element 160A of the second die 604B. Similarly, the receiver replica circuit element 126B of the third die 604C is manufactured in close proximity to the receiver circuit element 160B of the fourth die 604D. In the example in Figure 4, the receiver replica circuit element 126A is manufactured to the right of the first die 604A, and the receiver circuit element 160A is manufactured to the left of the second die 604B. Also, the receiver replica circuit element 126B is manufactured to the right of the third die 604C, and the receiver circuit element 160B is manufactured to the left of the fourth die 604D. By manufacturing the receiver replica circuit elements of the opto-emulator transmitter near the corresponding receiver circuit elements of the opto-emulator receiver on wafer 600, process variations are reduced. Reducing process variations in the receiver replica circuit elements of the opto-emulator transmitter and the associated receiver circuit elements of the opto-emulator receiver reduces inconsistencies and improves CTR linearity. In other examples, the positions of the receiver replica circuit elements (e.g., receiver replica circuit element 126A) and associated receiver circuit elements (e.g., receiver circuit element 160A) on the die may vary (e.g., top / bottom option, bottom / top option, left / right option, right / left option, etc.).

[0057] In some examples, the opto-emulator transmitter (e.g., opto-emulator transmitter 102A in Figure 2) and the current controller have a first terminal (e.g., the first terminal 224 in Figure 2), a second terminal (e.g., the third terminal 228 in Figure 2), and a third terminal (e.g., the fourth terminal 230 in Figure 2). The opto-emulator transmitter also includes an oscillator circuit (e.g., LC oscillator 238 in Figure 2), which has a first terminal (e.g., the first terminal 240 in Figure 2), a second terminal (e.g., the second terminal 242 in Figure 2), and a third terminal (e.g., the third terminal 244 in Figure 2). The first terminal of the oscillator circuit is coupled to the second terminal of the current controller. The opto-emulator transmitter also includes a receiver replica circuit element (e.g., receiver replica circuit element 126 in Figure 1), which has a first terminal (e.g., first terminal 128 in Figure 1), a second terminal (e.g., second terminal 130 in Figure 1), and a third terminal (e.g., third terminal 132 in Figure 1). The first terminal of the receiver replica circuit element is coupled to the second terminal of the oscillator circuit. The second terminal of the receiver replica circuit element is coupled to the third terminal of the oscillator circuit. The third terminal of the receiver replica circuit element is coupled to the third terminal of the current controller.

[0058] In some examples, the receiver replica circuit element includes a transistor (e.g., transistor M1 in this specification) having a first terminal, a second terminal, and a control terminal. The first terminal of the transistor is coupled to the third terminal of the receiver replica circuit element. In some examples, the receiver replica circuit element includes a rectifier circuit (e.g., differential rectifier circuit 258 in Figure 2), the rectifier circuit having a first terminal (e.g., first terminal 260 in Figure 2), a second terminal (e.g., second terminal 262 in Figure 2), and a third terminal (e.g., third terminal 264 in Figure 2). The first terminal of the rectifier circuit is coupled to the first terminal of the receiver replica circuit element. The second terminal of the rectifier circuit is coupled to the second terminal of the receiver replica circuit element. The third terminal of the rectifier circuit is coupled to the third terminal of the receiver replica circuit element. The third terminal of the receiver replica circuit element is coupled to the control terminal of the transistor. In some cases, a rectifier circuit is a differential rectifier circuit, and an oscillator circuit is a differential oscillator circuit.

[0059] In some examples, the opto-emulator transmitter also includes an attenuator circuit (e.g., attenuator circuit 248 in Figure 2), the attenuator circuit having a first terminal (e.g., first terminal 250 in Figure 2), a second terminal (e.g., second terminal 252 in Figure 2), a third terminal (e.g., third terminal 254 in Figure 2), and a fourth terminal (e.g., fourth terminal 256 in Figure 2). The first terminal of the attenuator circuit is coupled to the second terminal of the oscillator circuit. The second terminal of the attenuator circuit is coupled to the third terminal of the oscillator circuit. The third terminal of the attenuator circuit is coupled to the first terminal of the receiver replica circuit element. The fourth terminal of the attenuator circuit is coupled to the second terminal of the receiver replica circuit element.

[0060] In some examples, the opto-emulator transmitter includes a fuse (e.g., fuse 204 in Figure 2), a reverse protection circuit element (e.g., reverse protection circuit element 210 in Figure 2), and an ESD circuit element (e.g., an ESD circuit element in Figure 2). The fuse has a first terminal (e.g., the first terminal 206 in Figure 2) and a second terminal (e.g., the second terminal 208 in Figure 2). The reverse protection circuit element has a first terminal (e.g., the first terminal 212 in Figure 2) and a second terminal (e.g., the second terminal 214 in Figure 2). The ESD circuit element has a first terminal (e.g., the first terminal 218 in Figure 2) and a second terminal (e.g., the second terminal 220 in Figure 2). The second terminal of the fuse is coupled to the first terminal of the reverse protection circuit element and to the first terminal of the ESD circuit element. The second terminal of the reverse protection circuit element is connected to the first terminal of the current controller.

[0061] In some examples, the current controller 222 includes a reliability clamp circuit element (e.g., reliability clamp circuit element 502 in Figure 5), a shunt bypass circuit element (e.g., shunt bypass circuit element 504 in Figure 5), a source follower circuit element (e.g., source follower circuit element 506 in Figure 5), a current mirror circuit element (e.g., current mirror circuit element 508 in Figure 5), and / or a current comparator circuit element (e.g., current comparator circuit element 510 in Figure 5). In some examples, the current controller has a fourth terminal (e.g., a second terminal 226 in Figure 2), and the opto-emulator transmitter includes a diode emulator (e.g., diode emulator 232 in Figure 2) having a first terminal (e.g., a first terminal 234 in Figure 2) and a second terminal (e.g., a second terminal 236 in Figure 2). The first terminal of the diode emulator is coupled to the fourth terminal of the current controller. In some examples, the diode emulator includes a VF bias circuit element (for example, VF bias circuit element 512 in Figure 5).

[0062] In some examples, the current controller includes reliability clamp circuit elements and shunt bypass circuit elements. The reliability clamp circuit elements are configured to clamp the voltage and current levels of the opto-emulator transmitter. The shunt bypass circuit elements are configured to regulate the output current to the oscillator circuit. In some examples, the current controller includes source follower circuit elements, current mirror circuit elements, and current comparator circuit elements. The source follower circuit elements are configured to set the gain level of the current controller. The current mirror circuit elements are configured to mirror the current of the shunt bypass circuit elements to the current comparator circuit elements. The current comparator circuit elements are configured to compare the mirrored current with the feedback current based on the operation of the receiver replica circuit elements.

[0063] In some examples, an opto-emulator transmitter (e.g., opto-emulator transmitter 102 in Figure 1) includes a transmitter circuit element (e.g., transmitter circuit element 112 in Figure 1) and a receiver replica circuit element (e.g., receiver replica circuit element 126 in Figure 1). The transmitter circuit element has a first terminal (e.g., first terminal 114 in Figure 1), a second terminal (e.g., second terminal 116 in Figure 1), a third terminal (e.g., third terminal 118 in Figure 1), a fourth terminal (e.g., fourth terminal 120 in Figure 1), and a fifth terminal (e.g., fifth terminal 122 in Figure 1). The receiver replica circuit element has a first terminal (e.g., first terminal 128 in Figure 1), a second terminal (e.g., second terminal 130 in Figure 1), and a third terminal (e.g., third terminal 132 in Figure 1). The first terminal of the receiver replica circuit element is coupled to the third terminal of the transmitter circuit element. The second terminal of the receiver replica circuit element is coupled to the fourth terminal of the transmitter circuit element. The third terminal of the receiver replica circuit element is coupled to the fifth terminal of the transmitter circuit element. In such an example, the transmitter circuit element is configured to receive current at the first terminal of the transmitter circuit element, provide a transmit signal at the third and fourth terminals of the transmitter circuit element in response to the current, receive a feedback signal from the receiver replica circuit element at the fifth terminal of the transmitter circuit element in response to the transmit signal, and provide a regulated transmit signal at the third and fourth terminals of the transmitter circuit element in response to the current and the feedback signal.

[0064] In some examples, the current is a first current, and the transmitter circuit elements include an oscillator circuit (e.g., LC oscillator 238 in Figure 2) and a current controller (e.g., current controller 222 in Figure 2). In such examples, the current controller is configured to compare a second current based on a feedback signal (e.g., current through transistor M1) with the output current to the LC oscillator (e.g., current through transistors M13 and M14), and to adjust the second current to the oscillator circuit in response to the comparison result.

[0065] In some examples, the receiver replica circuit elements include a differential rectifier (e.g., differential rectifier circuit 258 in Figure 2) and a transistor (e.g., transistor M1 in Figure 2). In such examples, the differential rectifier has a first terminal (e.g., first terminal 260 in Figure 2), a second terminal (e.g., second terminal 262 in Figure 2), and a third terminal (e.g., third terminal 264 in Figure 2). The transistor has a first terminal, a second terminal, and a control terminal. The third terminal of the differential rectifier is coupled to the control terminal of the transistor. The differential rectifier is configured to receive the transmit signal at the first and second terminals of the differential rectifier and, in response to the transmit signal, provide the rectified signal at the third terminal of the differential rectifier.

[0066] In some examples, the opto-emulator transmitter includes an attenuator circuit (e.g., attenuator circuit 248 in Figure 2) between the transmitter circuit and the receiver replica circuit. In such examples, the attenuator circuit is configured to attenuate the transmitted signal based on an isolation circuit attenuation coefficient (e.g., 1 / k scaling, where k is the isolation circuit attenuation coefficient).

[0067] In some examples, the opto-emulator circuit includes an opto-emulator receiver (e.g., opto-emulator receiver 150A in Figures 3 and 4) and an opto-emulator transmitter (e.g., opto-emulator transmitter 102A in Figures 2 and 4). The opto-emulator receiver includes a first rectifier circuit (e.g., differential rectifier circuit 304 in Figure 3) and a first transistor (e.g., transistor M2 in Figures 3 and 4). The first rectifier circuit has a first terminal (e.g., first terminal 306), a second terminal (e.g., second terminal 308), and a third terminal (e.g., fourth terminal 312). The first transistor has a first terminal, a second terminal, and a control terminal. The control terminal of the transistor is coupled to the third terminal of the rectifier circuit. The opto-emulator receiver includes a current controller (e.g., current controller 222 in Figure 2, associated circuit element in Figure 5), an oscillator circuit (e.g., LC oscillator in Figure 2), a second rectifier circuit (e.g., differential rectifier circuit 258 in Figure 2), and a second transistor (e.g., transistor M1 in Figure 2). The current controller has a first terminal (e.g., first terminal 224 in Figure 2), a second terminal (e.g., third terminal 228 in Figure 2), and a third terminal (e.g., fourth terminal 230 in Figure 2). The oscillator circuit has a first terminal (e.g., first terminal 240 in Figure 2), a second terminal (e.g., second terminal 242 in Figure 2), and a third terminal (e.g., third terminal 244 in Figure 2). The first terminal of the oscillator circuit is coupled to the second terminal of the current controller. The second rectifier circuit has a first terminal (e.g., the first terminal 260 in Figure 2), a second terminal (e.g., the second terminal 262 in Figure 2), and a third terminal (e.g., the third terminal 264 in Figure 2). The first terminal of the second rectifier circuit is coupled to the second terminal of the oscillator circuit. The second terminal of the second rectifier circuit is coupled to the third terminal of the oscillator circuit. The second transistor has a first terminal, a second terminal, and a control terminal. The control terminal of the transistor is coupled to the third terminal of the second rectifier circuit.

[0068] In some examples, the opto-emulator includes an isolation circuit element (e.g., isolation circuit element 134 in Figure 1, or isolation circuit element 134A in Figure 4) between the opto-emulator transmitter and the opto-emulator receiver. The isolation circuit element has a first terminal (e.g., the first terminal 136 in Figures 1 and 4), a second terminal (e.g., the second terminal 138 in Figures 1 and 4), a third terminal (e.g., the third terminal 140 in Figures 1 and 4), and a fourth terminal (e.g., the fourth terminal 142 in Figures 1 and 4). The first terminal of the isolation circuit element is coupled to the second terminal of the oscillator circuit. The second terminal of the isolation circuit element is coupled to the third terminal of the oscillator circuit. The third terminal of the isolation circuit element is coupled to the first terminal of the first rectifier circuit. The fourth terminal of the isolation circuit element is coupled to the second terminal of the first rectifier circuit, and the isolation circuit element includes a transformer (for example, transformer circuit element 406 in Figure 4).

[0069] In some examples, the opto-emulator transmitter includes an attenuator circuit (e.g., attenuator circuit 248 in Figures 2 and 4), the attenuator circuit having a first terminal (e.g., first terminal 250 in Figure 2), a second terminal (e.g., second terminal 252 in Figure 2), a third terminal (e.g., third terminal 254 in Figure 2), and a fourth terminal (e.g., fourth terminal 256 in Figure 2). The first terminal of the attenuator circuit is coupled to the second terminal of the oscillator circuit. The second terminal of the attenuator circuit is coupled to the third terminal of the oscillator circuit. The third terminal of the oscillator circuit is coupled to the first terminal of the rectifier circuit. The fourth terminal of the oscillator circuit is coupled to the second terminal of the rectifier circuit. The attenuator circuit has an attenuation coefficient that matches the attenuation of the isolation circuit element.

[0070] In some examples, the opto-emulator transmitter, isolation circuit elements, and opto-emulator receiver each reside on a separate integrated circuit die. In some examples, the first rectifier circuit is a first differential rectifier circuit, the second rectifier circuit is a second differential rectifier circuit, the oscillator circuit is a differential oscillator circuit, the second rectifier circuit is a replica of the first rectifier circuit, and the second transistor is a replica of the first transistor. In some examples, the second rectifier circuit is configured to receive a transmit signal from the oscillator circuit and provide a feedback signal in response to the transmit signal. In such examples, the current controller is configured to compare the current based on the feedback signal (e.g., the current through transistor M1) with a target current (e.g., the output current to the LC oscillator), obtain a comparison result, and adjust the current to the oscillator circuit in response to the comparison result.

[0071] In this description, the term “coupled” may encompass connections, communications, or signaling paths that enable a functional relationship consistent with the description herein. For example, if device A generates a signal to control control device B to perform a certain action, then (a) in the first example, device A is coupled to device B by a direct connection, and (b) in the second example, device A is coupled to device B via intermediary component C, provided that intermediary component C does not alter the functional relationship between device A and device B, so that device B is controlled by device A via a control signal generated by device A.

[0072] Furthermore, in this document, the phrase "based on ~" means "based on ~ at least partially." Therefore, if X is based on Y, X can be a function of Y and any number of other factors.

[0073] A device “configured” to perform a certain task or function may be configured by the manufacturer at the time of manufacture to perform that function (e.g., by programming and / or wiring), or may be configured (or reconfigurable) by the user after manufacture to perform such function and / or other additional or alternative functions. Such configuration may be via the device’s firmware and / or software programming, or via the configuration and / or layout of hardware components, the interconnection of devices, or a combination thereof.

[0074] As used herein, the terms “terminal,” “node,” “interconnection,” “pin,” and “lead” are interchangeable. Unless otherwise specified, these terms are generally used to mean interconnections or terminations between device elements, circuit elements, integrated circuits, devices, or other electronic or semiconductor components.

[0075] A circuit or device described as containing certain components may instead be adapted to be coupled to those components to form the described circuit element or device. For example, a structure described as containing one or more semiconductor elements (such as transistors), one or more passive elements (such as resistors, capacitors, and / or inductors), and / or one or more power sources (such as voltage and / or current power supplies) may instead contain only the semiconductor elements within a single physical device (e.g., a semiconductor die and / or integrated circuit (IC) package), which may be adapted to be coupled to at least some of the passive elements and / or power sources, thereby forming the described structure, for example, by an end user and / or a third party, either at the time of manufacture or at a later point in time.

[0076] The circuits described herein are reconfigurable to include additional or different components to provide functionality at least partially similar to the functionality available before the replacement of components. Unless otherwise stated, components indicated as resistors generally represent any one or more elements that are coupled in series or in parallel to provide the amount of impedance represented by the indicated resistors. For example, a resistor described herein as a single component may instead be a plurality of resistors or capacitors, each of which may be coupled in parallel between the same nodes. For example, a resistor or capacitor illustrated and described herein as a single component may instead be a plurality of resistors or capacitors coupled in series between the same two nodes, each as a single resistor or capacitor.

[0077] Some elements of the described example are included in a certain integrated circuit, while other elements are outside that integrated circuit, but additional or fewer features may be incorporated into the integrated circuit in other illustrative examples. Also, some or all of the features shown as being outside the integrated circuit may be included in the integrated circuit, and / or some features shown as being inside the integrated circuit may be incorporated outside the integrated circuit. As used herein, the term “integrated circuit” means one or more circuits that are (1) incorporated in / on a semiconductor substrate, (2) incorporated in a single semiconductor package, (3) incorporated in the same module, and / or (4) incorporated in / on the same printed circuit board.

[0078] In the preceding description, the use of the term "grounding" includes chassis grounding, earth grounding, floating grounding, virtual grounding, digital grounding, common grounding, and / or any other form of grounding connection applicable to or suitable for the teachings described herein. In this description, unless otherwise stated, "about," "approximately," or "substantially" preceding a parameter means + / - 10 percent of the parameter, and in the case of a parameter of zero, it means a reasonable range of values ​​near zero.

[0079] Modifications to the described embodiments are permitted within the scope of the claims, and other embodiments are possible.

Claims

1. Opto emulator transmitter, A current controller having a first terminal, a second terminal, and a third terminal, An oscillator circuit having a first terminal, a second terminal, and a third terminal, wherein the first terminal of the oscillator circuit is coupled to the second terminal of the current controller, A receiver replica circuit element having a first terminal, a second terminal, and a third terminal, wherein the first terminal of the receiver replica circuit element is coupled to the second terminal of the oscillator circuit, the second terminal of the receiver replica circuit element is coupled to the third terminal of the oscillator circuit, and the third terminal of the receiver replica circuit element is coupled to the third terminal of the current controller, An opto-emulator transmitter, including one.

2. The opto-emulator transmitter according to claim 1, wherein the receiver replica circuit element includes a transistor having a first terminal, a second terminal, and a control terminal, and the first terminal of the transistor is coupled to the third terminal of the receiver replica circuit element.

3. An opto-emulator transmitter according to claim 2, wherein the receiver replica circuit element includes a rectifier circuit having a first terminal, a second terminal, and a third terminal, the first terminal of the rectifier circuit being coupled to the first terminal of the receiver replica circuit element, the second terminal of the rectifier circuit being coupled to the second terminal of the receiver replica circuit element, the third terminal of the rectifier circuit being coupled to the third terminal of the receiver replica circuit element, and the third terminal of the receiver replica circuit element being coupled to the control terminal of the transistor.

4. An opto-emulator transmitter according to claim 3, wherein the rectifier circuit is a differential rectifier circuit and the oscillator circuit is a differential oscillator circuit.

5. An opto-emulator transmitter according to claim 1, further comprising an attenuator circuit having a first terminal, a second terminal, a third terminal, and a fourth terminal, wherein the first terminal of the attenuator circuit is coupled to the second terminal of the oscillator circuit, the second terminal of the attenuator circuit is coupled to the third terminal of the oscillator circuit, the third terminal of the attenuator circuit is coupled to the first terminal of the receiver replica circuit element, and the fourth terminal of the attenuator circuit is coupled to the second terminal of the receiver replica circuit element.

6. An opto-emulator transmitter according to claim 1, further comprising a fuse, a reverse protection circuit element, and an electrostatic discharge (ESD) circuit element, wherein the fuse has a first terminal and a second terminal, the reverse protection circuit element has a first terminal and a second terminal, the ESD circuit element has a first terminal and a second terminal, the second terminal of the fuse is coupled to the first terminal of the reverse protection circuit element and the first terminal of the ESD circuit element, and the second terminal of the reverse protection circuit element is coupled to the first terminal of the current controller.

7. An opto-emulator transmitter according to claim 1, wherein the current controller includes a reliability clamp circuit element and a shunt bypass circuit element, the reliability clamp circuit element is configured to clamp the voltage and current of the opto-emulator transmitter, and the shunt bypass circuit element is configured to adjust the output current to the oscillator circuit.

8. An opto-emulator transmitter according to claim 7, wherein the current controller includes a source follower circuit element, a current mirror circuit element, and a current comparator circuit element, the source follower circuit element being configured to set the gain level of the current controller, the current mirror circuit element being configured to mirror the current of the shunt bypass circuit element to the current comparator circuit element, and the current comparator circuit element being configured to compare the mirrored current with a feedback current based on the operation of the receiver replica circuit element.

9. An opto-emulator transmitter according to claim 1, wherein the current controller has a fourth terminal, and the opto-emulator transmitter further includes a diode emulator having a first terminal and a second terminal, wherein the first terminal of the diode emulator is coupled to the fourth terminal of the current controller.

10. Opto emulator transmitter, A transmitter circuit element having a first terminal, a second terminal, a third terminal, a fourth terminal, and a fifth terminal, A receiver replica circuit element having a first terminal, a second terminal, and a third terminal, wherein the first terminal of the receiver replica circuit element is connected to the third terminal of the transmitter circuit element, the second terminal of the receiver replica circuit element is connected to the fourth terminal of the transmitter circuit element, and the third terminal of the receiver replica circuit element is connected to the fifth terminal of the transmitter circuit element, Includes, The aforementioned transmitter circuit element is The first terminal of the transmitter circuit element receives current, In response to the current, the third and fourth terminals of the transmitter circuit element provide a transmit signal. A feedback signal in response to the transmission signal is received from the receiver replica circuit element at the fifth terminal of the transmitter circuit element. In response to the current and the feedback signal, the third and fourth terminals of the transmitter circuit element provide a regulated transmit signal. It is configured in such a way. Opto emulator transmitter.

11. An opto-emulator transmitter according to claim 10, The current is a first current, the transmitter circuit element includes an oscillator circuit and a current controller, and the current controller is To obtain the comparison result, the second current based on the feedback signal is compared with the target current. In response to the comparison result, the second current to the oscillator circuit is adjusted. An opto-emulator transmitter configured as follows.

12. An opto-emulator transmitter according to claim 11, wherein the current is a first current, the transmitter circuit element includes an oscillator circuit and a current controller, and the current controller is configured to limit the first current based on a target voltage for the transmitter circuit element.

13. The opto-emulator transmitter according to claim 10, wherein the receiver replica circuit element includes a differential rectifier and a transistor, the differential rectifier having a first terminal, a second terminal and a third terminal, the transistor having a first terminal, a second terminal and a control terminal, the third terminal of the differential rectifier being coupled to the control terminal of the transistor, and the differential rectifier is The first and second terminals of the differential rectifier receive the transmission signal. In response to the transmission signal, the third terminal of the differential rectifier provides a rectified signal. It is configured in such a way. Opto emulator transmitter.

14. An opto-emulator transmitter according to claim 10, further comprising an attenuator circuit between the transmitter circuit and the receiver replica circuit, wherein the attenuator circuit is configured to attenuate the transmitted signal based on an isolation circuit attenuation coefficient.

15. Optoemulator circuit, Opto emulator receiver, Opto emulator transmitter, Includes, The optoemulator receiver, A first rectifier circuit having a first terminal, a second terminal, and a third terminal, A first transistor having a first terminal, a second terminal, and a control terminal, wherein the control terminal of the transistor is coupled to the third terminal of the rectifier circuit, Includes, The aforementioned opto-emulator transmitter, A current controller having a first terminal, a second terminal, and a third terminal, An oscillator circuit having a first terminal, a second terminal, and a third terminal, wherein the first terminal of the oscillator circuit is coupled to the second terminal of the current controller, A second rectifier circuit having a first terminal, a second terminal, and a third terminal, wherein the first terminal of the second rectifier circuit is coupled to the second terminal of the oscillator circuit, and the second terminal of the second rectifier circuit is coupled to the third terminal of the oscillator circuit, A second transistor having a first terminal, a second terminal, and a control terminal, wherein the control terminal of the transistor is coupled to the third terminal of the second rectifier circuit, An opto-emulator circuit, including one.

16. The opto-emulator circuit according to claim 15, An opto-emulator circuit comprising an isolation circuit element between the opto-emulator transmitter and the opto-emulator receiver, wherein the isolation circuit element has a first terminal, a second terminal, a third terminal, and a fourth terminal, the first terminal of the isolation circuit element is coupled to the second terminal of the oscillator circuit, the second terminal of the isolation circuit element is coupled to the third terminal of the oscillator circuit, the third terminal of the isolation circuit element is coupled to the first terminal of the first rectifier circuit, the fourth terminal of the isolation circuit element is coupled to the second terminal of the first rectifier circuit, and the isolation circuit element includes a transformer.

17. An opto-emulator circuit according to claim 16, wherein the opto-emulator transmitter includes an attenuator circuit having a first terminal, a second terminal, a third terminal, and a fourth terminal, wherein the first terminal of the attenuator circuit is coupled to the second terminal of the oscillator circuit, the second terminal of the attenuator circuit is coupled to the third terminal of the oscillator circuit, the third terminal of the oscillator circuit is coupled to the first terminal of the rectifier circuit, the fourth terminal of the oscillator circuit is coupled to the second terminal of the rectifier circuit, and the attenuator circuit has an attenuation coefficient that matches the attenuation of the isolation circuit element.

18. An opto-emulator circuit according to claim 16, wherein each of the opto-emulator transmitter, the isolation circuit element, and the opto-emulator receiver is located on a separate integrated circuit die.

19. An opto-emulator circuit according to claim 15, wherein the first rectifier circuit is a first differential rectifier circuit, the second rectifier circuit is a second differential rectifier circuit, the oscillator circuit is a differential oscillator circuit, the second rectifier circuit is a replica of the first rectifier circuit, and the second transistor is a replica of the first transistor.

20. The opto-emulator circuit according to claim 15, The second rectifier circuit described above, The oscillator circuit receives the transmission signal, A feedback signal is provided in response to the aforementioned transmission signal. It is configured in such a way, The current controller, To obtain the comparison result, the current based on the feedback signal is compared with the target current. The current to the oscillator circuit is adjusted in response to the comparison result. It is configured in such a way. Opto-emulator circuit.

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