TWI873945B - Differential amplification device and compensation method thereof - Google Patents

Abstract

The invention provides a differential amplification device and a compensation method thereof. The differential amplification device includes a first-end signal circuit, a second-end signal circuit and a controller. The first-end signal circuit and the second-end signal circuit respectively generate a first-end signal and a second-end signal of a differential output signal to a first terminal of a transmission path. Based on a transmitted differential signal at a second terminal of the transmission path, the controller adjusts the first component parameter of the first-end signal circuit or the second component parameter of the second-end signal circuit to compensate the asymmetrical influence caused by the transmission path on the first-end signal and the second-end signal of the transmitted differential signal. Wherein, the adjustment of the first component parameter of the first-end signal circuit is independent of the adjustment of the second component parameter of the second-end signal circuit.

Description

Differential amplifier device and compensation method thereof

The present invention relates to an electronic circuit, and more particularly to a differential amplifier and a compensation method thereof.

The differential output signal of a transmitting device is transmitted to a receiving device through a transmission path. For example, the differential output signal of a transmitting device is transmitted to a USB receiving device through an integrated circuit package, a printed circuit board (PCB), a Universal Serial Bus (USB) connector, and a USB cable. Generally speaking, the non-ideal effects of the transmission path will affect the differential signal, causing symmetry differences in the differential signal (transmitted differential signal) received by the receiving device from the transmission path. For example, the asymmetric effect of the transmission path on the first end signal and the second end signal in the transmitted differential signal may include: the attenuation of the first end signal of the transmitted differential signal by the transmission path is different from the attenuation of the second end signal of the transmitted differential signal by the transmission path. Based on this, the common mode voltage of the transmitted differential signal received by the receiving device will be far away from the rated common mode voltage level (e.g., 0 V). For the USB Fourth Edition (USB4) specification, it is unacceptable for the common mode voltage of the transmitted differential signal to be far away from the rated common mode voltage level.

The present invention provides a differential amplifier device and a compensation method thereof to compensate for the asymmetric effect of a transmission path on a first-end signal and a second-end signal in a transmitted differential signal.

In one embodiment of the present invention, the above-mentioned differential amplifier device is used to generate a differential output signal to the first end of a transmission path. The differential amplifier device includes a first-end signal circuit, a second-end signal circuit and a controller. The first-end signal circuit generates a first-end signal in the differential output signal. The second-end signal circuit is coupled to the first-end signal circuit. The second-end signal circuit generates a second-end signal in the differential output signal. The controller is coupled to the first-end signal circuit and the second-end signal circuit. The controller adjusts at least one first component parameter of the first-end signal circuit or at least one second component parameter of the second-end signal circuit based on the transmitted differential signal at the second end of the transmission path to compensate for the asymmetric effect of the transmission path on a first-end signal and a second-end signal in the transmitted differential signal. The adjustment of the at least one first component parameter of the first-end signal circuit is independent of the adjustment of the at least one second component parameter of the second-end signal circuit.

In an embodiment of the present invention, the above compensation method is used to compensate for the asymmetric effect of the transmission path on the first end signal and the second end signal in the transmitted differential signal. The compensation method includes: generating a first-end signal in a differential output signal from a first-end signal circuit to a first end of a transmission path; generating a second-end signal in a differential output signal from a second-end signal circuit to the first end of the transmission path, wherein the second-end signal circuit is coupled to the first-end signal circuit; and adjusting at least one first component parameter of the first-end signal circuit or at least one second component parameter of the second-end signal circuit based on the transmitted differential signal at the second end of the transmission path to compensate for the asymmetric effect of the transmission path on the first-end signal and the second-end signal of the transmitted differential signal, wherein the adjustment of the at least one first component parameter of the first-end signal circuit is independent of the adjustment of the at least one second component parameter of the second-end signal circuit.

Based on the above, the controller of various embodiments of the present invention can adjust the component parameters of the first-end signal circuit independently of the component parameters of the second-end signal circuit, that is, the adjustment of the first-end signal in the differential output signal can be independent of the adjustment of the second-end signal in the differential output signal. Generally speaking, the transmission path may produce an asymmetric effect on the transmitted differential signal. For example, the attenuation degree of the transmission path on the first-end signal of the transmitted differential signal is different from the attenuation degree of the transmission path on the second-end signal of the transmitted differential signal. Due to the asymmetric effect of the transmission path on the transmitted differential signal, the common mode voltage of the transmitted differential signal received by the receiving device may be far away from the rated common mode voltage level (e.g., 0 V or other target level). Based on the transmitted differential signal of the transmission path, the controller can adjust/set the component parameters of the first-end signal circuit and/or the component parameters of the second-end signal circuit accordingly. Because the adjustment of the component parameters of the first-end signal circuit can be independent of the adjustment of the component parameters of the second-end signal circuit, the differential amplifier device can compensate for the asymmetric effect of the transmission path on the first-end signal and the second-end signal of the transmitted differential signal.

In order to make the above features and advantages of the present invention more clearly understood, embodiments are specifically cited below and described in detail with reference to the accompanying drawings.

The term "coupled (or connected)" used in the entire specification of this case (including the scope of the patent application) may refer to any direct or indirect means of connection. For example, if the text describes a first device coupled (or connected) to a second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be indirectly connected to the second device through other devices or some connection means. The terms "first", "second", etc. mentioned in the entire specification of this case (including the scope of the patent application) are used to name the elements or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements, nor to limit the order of elements. In addition, wherever possible, elements/components/steps with the same number in the drawings and embodiments represent the same or similar parts. Elements/components/steps using the same reference numerals or the same terms in different embodiments may refer to each other for related descriptions.

FIG1 is a schematic diagram of a circuit block of an electronic device 100 according to an embodiment of the present invention. The electronic device 100 shown in FIG1 includes a transmitting device TX11 and a receiving device RX11, wherein the transmitting device TX11 is configured in an integrated circuit package PKG11, and the receiving device RX11 is configured in an integrated circuit package PKG12. The integrated circuit package PKG11 is configured on a printed circuit board (PCB) PCB11, and the integrated circuit package PKG12 is configured on the printed circuit board PCB12. One end of the cable CBL11 is connected to a connector of the printed circuit board PCB11, and the other end of the cable CBL11 is connected to a connector of the printed circuit board PCB12. Based on actual design, the cable CBL11 may be a Universal Serial Bus (USB) cable or other cables.

The differential output signal (end signals TXp and TXn) of the differential amplifier device AMP11 in the transmitting device TX11 can be transmitted to the receiving device RX11 through the integrated circuit package PKG11, the printed circuit board PCB11, the cable CBL11, the printed circuit board PCB12 and the integrated circuit package PKG12. Usually, the common mode voltage of the differential signal at the test point TP1 can match the rated common mode voltage level (such as 0 V or other target standard level, determined by the actual design). In general, the transmission path of the differential output signal has non-ideal effects. For example, non-ideal effects may include discontinuousness, mismatch, reflection, coupling and other effects. The non-ideal effects of the transmission path may cause common-mode noise to be generated in the transmitted differential signal (end signals RXp and RXn), which will affect the receiving capability of the receiving device RX11. Therefore, the USB 4th version (USB4) specifies that this noise must be less than 100m Vpp.

In detail, the non-ideal effects of the transmission path may produce an asymmetric effect on the transmitted differential signals (end signals RXp and RXn). For example, the attenuation degree of the end signal RXp of the transmission path may be different from the attenuation degree of the end signal RXn of the transmission path. Because of the asymmetric effect of the transmission path on the transmitted differential signals, the common-mode voltage of the transmitted differential signals received by the receiving device RX11 may drift away from the rated common-mode voltage level (e.g., 0 V or other target standard levels, determined by the actual design). That is, the common-mode voltage of the differential signals at the test points TP2, TP3', TP3 and/or TP4 may be far away from the rated common-mode voltage level.

Based on the transmitted differential signals (end signals RXp and RXn) of the transmission path, the differential amplifier AMP11 can independently adjust the end signals TXp and/or TXn of the differential output signals. For example, in response to the attenuation of the end signal RXp of the transmission path being greater than the attenuation of the end signal RXn of the transmission path, the differential amplifier AMP11 can increase the voltage level of the end signal TXp without adjusting the voltage level of the end signal TXn, or the differential amplifier AMP11 can decrease the voltage level of the end signal TXn without adjusting the voltage level of the end signal TXp. Therefore, the differential amplifier AMP11 can compensate for the asymmetric effect of the transmission path on the end signals RXp and/or RXn of the transmitted differential signals. For another example, in response to the attenuation of the opposite end signal RXp of the transmission path being less than the attenuation of the opposite end signal RXn of the transmission path, the differential amplifier AMP11 can lower the voltage level of the end signal TXp without adjusting the voltage level of the end signal TXn, or the differential amplifier AMP11 can increase the voltage level of the end signal TXn without adjusting the voltage level of the end signal TXp. Because the adjustment of the opposite end signal TXp can be independent of the adjustment of the opposite end signal TXn, the differential amplifier AMP11 can compensate for the asymmetric effect of the transmission path on the transmitted differential signal. Therefore, the differential amplifier AMP11 can compensate for the common mode voltage at the transmission end of the USB4 high-speed circuit, thereby meeting the requirements of the USB4 specification.

FIG2 is a circuit block diagram of a differential amplifier AMP21 according to an embodiment of the present invention. The differential amplifier AMP21 shown in FIG2 can refer to the relevant description of the differential amplifier AMP11 shown in FIG1 and be deduced by analogy. Based on the terminal signals VIn and VIp of the differential input signal DSin, the differential amplifier AMP21 shown in FIG2 can generate a differential output signal DSout to the first end of the transmission path. Based on the actual test scenario, the transmission path may include a transmission path from the differential amplifier AMP11 shown in FIG1 (differential amplifier AMP21 shown in FIG2) to any one of the test points TP1, TP2, TP3', TP3 and TP4. In the embodiment shown in FIG2, the differential amplifier AMP21 includes a controller 110 and an amplifier 120. 2 includes an end signal circuit 121 and an end signal circuit 122. The end signal circuit 122 is directly or indirectly coupled to the end signal circuit 121. Based on the control of the controller 110, the amplifier 120 can adjust the end signal TXn of the differential output signal DSout independently of adjusting the end signal TXp of the differential output signal DSout.

According to different designs, in some embodiments, the controller 110 may be implemented as a hardware circuit. In other embodiments, the controller 110 may be implemented as firmware, software, or a combination of the two. In still other embodiments, the controller 110 may be implemented as a combination of hardware, firmware, and software.

In terms of hardware, the controller 110 may be implemented as a logic circuit on an integrated circuit. For example, the functions of the controller 110 may be implemented in various logic blocks, modules, and circuits in one or more controllers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), central processing units (CPUs), and/or other processing units. The relevant functions of the controller 110 can be implemented as hardware circuits, such as various logic blocks, modules and circuits in an integrated circuit, using hardware description languages (such as Verilog HDL or VHDL) or other suitable programming languages.

In software form and/or firmware form, the relevant functions of the controller 110 can be implemented as programming codes. For example, the controller 110 is implemented using general programming languages (such as C, C++ or assembly language) or other suitable programming languages. The programming codes can be recorded/stored in a "non-transitory machine-readable storage medium". In some embodiments, the non-transitory machine-readable storage medium includes, for example, a semiconductor memory and/or a storage device. The semiconductor memory includes a memory card, a read-only memory (ROM), a flash memory, a programmable logic circuit or other semiconductor memory. The storage device includes a tape, a disk, a hard disk drive (HDD), a solid-state drive (SSD) or other storage devices. An electronic device (such as a computer, a CPU, a controller, a microcontroller or a microprocessor) can read and execute the programming code from the non-temporary machine-readable storage medium to implement the relevant functions of the controller 110.

FIG3 is a flow chart of a compensation method according to an embodiment of the present invention. The compensation method shown in FIG3 can compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn in the transmitted differential signal. Please refer to FIG2 and FIG3. In step S310, different end signal circuits of the amplifier 120 generate different end signals TXp and TXn in the differential output signal DSout to the first end of the transmission path. In detail, the end signal circuit 121 can generate the end signal TXp in the differential output signal DSout to the first end of the transmission path, and the end signal circuit 122 can generate the end signal TXn in the differential output signal DSout to the first end of the transmission path.

The controller 110 is coupled to the end signal circuit 121 and the end signal circuit 122. In step S320, based on the transmitted differential signal (end signals RXp and RXn) at the second end of the transmission path, the controller 110 can independently adjust one or more component parameters of the end signal circuit 121, or independently adjust one or more component parameters of the end signal circuit 122. That is, the controller 110 can adjust the component parameters of the end signal circuit 121 independently of the adjustment of the component parameters of the end signal circuit 122. Based on this, the adjustment of the end signal TXp can be independent of the adjustment of the end signal TXn to compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn in the transmitted differential signal. For example, in response to the attenuation of the end signal RXp of the transmission path being greater than the attenuation of the end signal RXn of the transmitted differential signal by the transmission path, the differential amplifier AMP21 can increase the voltage level of the end signal TXp without adjusting the voltage level of the end signal TXn, or the differential amplifier AMP21 can decrease the voltage level of the end signal TXn without adjusting the voltage level of the end signal TXp. Therefore, the differential amplifier AMP21 can compensate for the asymmetric effect of the transmission path on the end signals RXp and/or RXn of the transmitted differential signal. For another example, in response to the transmission path attenuation of the end signal RXp of the transmitted differential signal being less than the transmission path attenuation of the end signal RXn of the transmitted differential signal, the differential amplifier AMP21 can lower the voltage level of the end signal TXp without adjusting the voltage level of the end signal TXn, or the differential amplifier AMP21 can increase the voltage level of the end signal TXn without adjusting the voltage level of the end signal TXp. Because the adjustment of the opposite end signal TXp can be independent of the adjustment of the opposite end signal TXn, the differential amplifier AMP21 can compensate for the asymmetric effect of the transmission path on the transmitted differential signal. Therefore, the differential amplifier AMP21 can compensate for the common mode voltage at the transmission end of the USB4 high-speed circuit, thereby meeting the requirements of the USB4 specification.

FIG4 is a flow chart of a compensation method according to another embodiment of the present invention. In step S410, the controller 110 sets the end signal circuits 121 and 122 of the amplifier device AMP21 with preset parameters so that the end signal TXp or TXn of the differential output signal DSout is symmetrical to the rated common mode voltage level (e.g., 0 V or other target standard level, determined by the actual design). In step S420, the amplifier 120 of the amplifier device AMP21 outputs the differential output signal DSout to the first end of the transmission path. In step S430, the measuring device (not shown) measures the transmitted differential signal (end signal RXp and RXn) at the second end of the transmission path to obtain the first drift of the end signal RXp and the second drift of the end signal RXn of the transmitted differential signal. In step S440, according to the first drift and the second drift, the controller 110 independently adjusts the end signal TXp or TXn of the differential output signal DSout of the amplifier device AMP21. For example, when the attenuation of the transmission path opposite end signal RXp is greater than the attenuation of the transmission path opposite end signal RXn, the controller 110 can increase the voltage level of the end signal TXp without adjusting the voltage level of the end signal TXn, or the controller 110 can decrease the voltage level of the end signal TXn without adjusting the voltage level of the end signal TXp.

In summary, the controller 110 can adjust the component parameters of the end signal circuit 121 independently of the component parameters of the second end signal circuit 122. That is, the controller 110 can adjust the end signal TXp in the differential output signal DSout independently of the end signal TXn in the differential output signal DSout. Generally speaking, the transmission path may have an asymmetric effect on the transmitted differential signals (end signals RXp and RXn). For example, the attenuation degree of the end signal RXp in the transmission path is different from the attenuation degree of the end signal RXn in the transmission path. Due to the asymmetric effect of the transmission path on the end signals RXp and RXn, the common mode voltage of the end signals RXp and RXn received by the receiving device may be far from the rated common mode voltage level (e.g., 0 V or other target standard level). Based on the transmitted differential signal (end signals RXp and RXn) of the transmission path, the controller 110 can adjust/set the component parameters of the end signal circuit 121 and/or the component parameters of the end signal circuit 122 accordingly. Because the adjustment of the component parameters of the end signal circuit 121 can be independent of the adjustment of the component parameters of the end signal circuit 122, the differential amplifier AMP21 can compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn of the transmitted differential signal.

FIG5 is a circuit block diagram of an amplifier 120 according to an embodiment of the present invention. In the embodiment shown in FIG5 , the end signal circuit 121 of the amplifier 120 includes a load circuit 510, an amplifier circuit 520, and a current source CS51. The first end of the load circuit 510 is coupled to the voltage VCCA. The level of the voltage VCCA can be determined according to the actual design. The second end of the load circuit 510 is coupled to the output end of the end signal circuit 121 to provide the end signal TXp in the differential output signal DSout. The input end of the amplifier circuit 520 receives the end signal VIp in the differential input signal DSin. The first current end of the amplifier circuit 520 is coupled to the second end of the load circuit 510. The current source CS51 is coupled to the second current end of the amplifier circuit 520. The controller 110 can adjust/set one or more component parameters of the terminal signal circuit 121, wherein the component parameters include the impedance of the load circuit 510, the gain of the amplifier circuit 520, or the current value of the current source CS51.

In the embodiment shown in FIG. 5 , the end signal circuit 122 includes a load circuit 530, an amplifier circuit 540, and a current source CS52. The first end of the load circuit 530 is coupled to the voltage VCCA. The second end of the load circuit 530 is coupled to the output end of the end signal circuit 122 to provide an end signal TXn in the differential output signal DSout. The input end of the amplifier circuit 540 receives the end signal VIn in the differential input signal DSin. The first current end of the amplifier circuit 540 is coupled to the second end of the load circuit 530. The current source CS52 is coupled to the second current end of the amplifier circuit 540. The controller 110 can adjust/set one or more component parameters of the terminal signal circuit 122, wherein the component parameters include the impedance of the load circuit 530, the gain of the amplifier circuit 540, or the current value of the current source CS52.

The second current terminal of the amplifier circuit 520 of the end signal circuit 121 is coupled to the second current terminal of the amplifier circuit 540 of the end signal circuit 122, and the output terminal of the end signal circuit 121 is coupled to the output terminal of the end signal circuit 122. In the embodiment shown in FIG5 , the amplifier 120 further includes resistors R53 and R54. The first end of the resistor R53 is coupled to the output terminal of the end signal circuit 121. The second end of the resistor R53 is coupled to the output terminal of the end signal circuit 122. The first end of the resistor R54 is coupled to the second current terminal of the amplifier circuit 520. The second end of the resistor R54 is coupled to the second current terminal of the amplifier circuit 540.

In the embodiment shown in FIG5 , the load circuit 510 includes a variable resistor R51, and the amplifier circuit 520 includes a driving unit 521 and an amplifier unit 522. The variable resistor R51 is controlled by the controller 110. The first end of the variable resistor R51 is coupled to the voltage VCCA. The second end of the variable resistor R51 is coupled to the output end of the end signal circuit 121. The first current end of the amplifier unit 522 is coupled to the second end of the load circuit 510. The second current end of the amplifier unit 522 is coupled to the current source CS51. The output end of the driving unit 521 is coupled to the control end of the amplifier unit 522. The input end of the driving unit 521 receives the end signal VIp in the differential input signal DSin.

In the embodiment shown in FIG. 5 , the driving unit 521 includes a buffer B51, and the amplifying unit 522 includes a transistor M51. The input end of the buffer B51 receives the terminal signal VIp in the differential input signal DSin. The output end of the buffer B51 is coupled to the control end of the amplifying unit 522. The controller 110 can control the gain of the buffer B51. The first end (e.g., the drain) of the transistor M51 is coupled to the second end of the load circuit 510. The second end (e.g., the source) of the transistor M51 is coupled to the current source CS51. The control end (e.g., the gate) of the transistor M51 is coupled to the output end of the driving unit 521. The controller 110 can control the channel width to length ratio (W/L) of the transistor M51. In order to increase the voltage level of the terminal signal TXp in the differential output signal DSout, the controller 110 may reduce the current value of the current source CS51, and/or reduce the channel width ratio of the transistor M51, and/or reduce the resistance value of the variable resistor R51, and/or reduce the gain of the buffer B51.

In response to the transmission path attenuating the end signal RXp of the transmitted differential signal more than the transmission path attenuating the end signal RXn of the transmitted differential signal, the controller 110 may reduce the current value of the current source CS51 (hereinafter referred to as the first current value), and/or reduce the gain of the amplifier circuit 520 (hereinafter referred to as the first gain), and/or reduce the impedance of the load circuit 510 (hereinafter referred to as the first impedance), and/or reduce the first current value and the first gain, and/or reduce the first gain and the first impedance, and/or reduce the first current value, the first gain, and the first impedance. Therefore, without adjusting the end signal TXn in the differential output signal DSout, the controller 110 may increase the voltage level of the end signal TXp in the differential output signal DSout to compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn of the transmitted differential signal.

In the embodiment shown in FIG. 5 , the load circuit 530 includes a variable resistor R52, and the amplifier circuit 540 includes a driving unit 541 and an amplifier unit 542. The variable resistor R52 is controlled by the controller 110. The first end of the variable resistor R52 is coupled to the voltage VCCA. The second end of the variable resistor R52 is coupled to the output end of the end signal circuit 122. The first current end of the amplifier unit 542 is coupled to the second end of the load circuit 530. The second current end of the amplifier unit 542 is coupled to the current source CS52. The output end of the driving unit 541 is coupled to the control end of the amplifier unit 542. The input end of the driving unit 541 receives the end signal VIn in the differential input signal DSin.

In the embodiment shown in FIG. 5 , the driving unit 541 includes a buffer B52, and the amplifying unit 542 includes a transistor M52. The input end of the buffer B52 receives the terminal signal VIn in the differential input signal DSin. The output end of the buffer B52 is coupled to the control end of the amplifying unit 542. The controller 110 can control the gain of the buffer B52. The first end (e.g., the drain) of the transistor M52 is coupled to the second end of the load circuit 530. The second end (e.g., the source) of the transistor M52 is coupled to the current source CS52. The control end (e.g., the gate) of the transistor M52 is coupled to the output end of the driving unit 541. The controller 110 can control the channel width ratio (W/L) of the transistor M52. In order to increase the voltage level of the terminal signal TXn in the differential output signal DSout, the controller 110 may reduce the current value of the current source CS52, and/or reduce the channel width ratio of the transistor M52, and/or reduce the resistance value of the variable resistor R52, and/or reduce the gain of the buffer B52.

In response to the transmission path attenuating the end signal RXp of the transmitted differential signal less than the transmission path attenuating the end signal RXn of the transmitted differential signal, the controller 110 can reduce the current value of the current source CS52 (hereinafter referred to as the second current value), and/or reduce the gain of the amplifier circuit 540 (hereinafter referred to as the second gain), and/or reduce the impedance of the load circuit 530 (hereinafter referred to as the second impedance), and/or reduce the second current value and the second gain, and/or reduce the second gain and the second impedance, and/or reduce the second current value, the second gain and the second impedance. Therefore, without adjusting the end signal TXp in the differential output signal DSout, the controller 110 may increase the voltage level of the end signal TXn in the differential output signal DSout to compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn of the transmitted differential signal.

FIG6 is a schematic circuit block diagram of an amplifier 120 according to another embodiment of the present invention. The amplifier 120, the end signal circuit 121, and the end signal circuit 122 shown in FIG6 can refer to the relevant description of the amplifier 120, the end signal circuit 121, and the end signal circuit 122 shown in FIG5, so they are not described here in detail. The difference from the amplifier 120 shown in FIG5 is that the amplifier 120 shown in FIG6 omits the resistor R53.

FIG7 is a circuit block diagram of an amplifier 120 according to another embodiment of the present invention. The end signal circuit 121 of the amplifier 120 shown in FIG7 includes a load circuit 710 and an amplifier circuit 720, and the end signal circuit 122 includes a load circuit 730 and an amplifier circuit 740. The load circuit 710 and the amplifier circuit 720 shown in FIG7 can refer to the relevant description of the load circuit 510 and the amplifier circuit 520 shown in FIG5, and the load circuit 730 and the amplifier circuit 740 shown in FIG7 can refer to the relevant description of the load circuit 530 and the amplifier circuit 540 shown in FIG5, so they are not described in detail here. In the embodiment shown in FIG7, the amplifier 120 further includes a current source CS71. The current source CS71 is coupled to a second current terminal of the amplifier circuit 720 of the end signal circuit 121 and a second current terminal of the amplifier circuit 740 of the end signal circuit 122 .

In the embodiment shown in FIG7 , the controller 110 can adjust/set one or more component parameters of the end signal circuit 121 and/or adjust/set one or more component parameters of the end signal circuit 122. The component parameters of the end signal circuit 121 include the impedance of the load circuit 710 and/or the gain of the amplifier circuit 720, and the component parameters of the end signal circuit 122 include the impedance of the load circuit 730 and/or the gain of the amplifier circuit 740.

In response to the transmission path attenuating the end signal RXp of the transmitted differential signal more than the transmission path attenuating the end signal RXn of the transmitted differential signal, the controller 110 may reduce the gain (hereinafter referred to as the first gain) of the amplifier circuit 720, and/or reduce the impedance (hereinafter referred to as the first impedance) of the load circuit 710, and/or reduce the first gain and the first impedance. Based on this, without adjusting the end signal TXn in the differential output signal DSout, the controller 110 may increase the voltage level of the end signal TXp in the differential output signal DSout to compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn of the transmitted differential signal.

In response to the transmission path attenuating the end signal RXp of the transmitted differential signal less than the transmission path attenuating the end signal RXn of the transmitted differential signal, the controller 110 may reduce the gain (hereinafter referred to as the second gain) of the amplifier circuit 740, and/or reduce the impedance (hereinafter referred to as the second impedance) of the load circuit 730, and/or reduce the second gain and the second impedance. Based on this, without adjusting the end signal TXp in the differential output signal DSout, the controller 110 may increase the voltage level of the end signal TXn in the differential output signal DSout to compensate for the asymmetric effect of the transmission path on the end signals RXp and RXn of the transmitted differential signal.

In summary, by independently adjusting the component parameters of the end signal circuit 121 or 122 by the controller 110, the differential amplifier AMP21 can compensate for the common-mode voltage difference caused by the non-ideal effect of the transmission path on the positive and negative end signals of the differential signal, thereby reducing the common-mode noise to meet the requirements of the USB4 specification.

Although the present invention has been disclosed as above by the embodiments, they are not intended to limit the present invention. Any person with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the scope of the attached patent application.

100: electronic equipment 110: controller 120: amplifier 121, 122: end signal circuit 510, 530, 710, 730: load circuit 520, 540, 720, 740: amplifier circuit 521, 541: driving unit 522, 542: amplifier unit AMP11, AMP21: differential amplifier device B51, B52: buffer CBL11: cable CS51, CS52, CS71: current source DSin: differential input signal DSout: differential output signal M51, M52: transistor PCB11, PCB12: printed circuit board PKG11, PKG12: integrated circuit package R51, R52: variable resistors R53, R54: resistors RX11: receiving device RXn, RXp, TXn, TXp, VIn, VIp: end signals S310, S320, S410, S420, S430, S440: steps TP1, TP2, TP3’, TP3, TP4: test points TX11: transmitting device

FIG. 1 is a schematic diagram of a circuit block of an electronic device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a circuit block of a differential amplifier according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a flow chart of a compensation method according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a flow chart of a compensation method according to another embodiment of the present invention. FIG. 5 is a schematic diagram of a circuit block of an amplifier according to an embodiment of the present invention. FIG. 6 is a schematic diagram of a circuit block of an amplifier according to another embodiment of the present invention. FIG. 7 is a schematic diagram of a circuit block of an amplifier according to another embodiment of the present invention.

S310, S320: Steps

Claims (16)

A differential amplifier device is used to generate a differential output signal to a first end of a transmission path. The differential amplifier device includes: a first-end signal circuit, used to generate a first-end signal in the differential output signal; a second-end signal circuit, coupled to the first-end signal circuit, wherein the second-end signal circuit generates a second-end signal in the differential output signal; and a controller, coupled to the first-end signal circuit and the second-end signal circuit, wherein the controller is based on At least one first component parameter of the first-end signal circuit or at least one second component parameter of the second-end signal circuit is adjusted based on a transmitted differential signal at a second end of the transmission path to compensate for the asymmetric effect of the transmission path on a first-end signal and a second-end signal in the transmitted differential signal, wherein the adjustment of the at least one first component parameter of the first-end signal circuit is independent of the adjustment of the at least one second component parameter of the second-end signal circuit. A differential amplifier device as described in claim 1, wherein the first-end signal circuit comprises: a load circuit having a first end coupled to a first voltage, wherein a second end of the load circuit is coupled to an output end of the first-end signal circuit, and the output end provides the first-end signal; an amplifier circuit having an input end for receiving a first-end signal in a differential input signal of the differential amplifier device, wherein a first current end of the amplifier circuit is coupled to the second end of the load circuit; and a current source coupled to a second current end of the amplifier circuit, wherein the at least one first component parameter comprises an impedance of the load circuit, a gain of the amplifier circuit, or a current value of the current source. A differential amplifier device as described in claim 2, wherein the load circuit includes: a variable resistor controlled by the controller, wherein a first end of the variable resistor is coupled to the first voltage, and a second end of the variable resistor is coupled to an output end of the first-end signal circuit. A differential amplifier device as described in claim 2, wherein the amplifier circuit comprises: an amplifier unit, wherein a first current terminal of the amplifier unit is coupled to the second terminal of the load circuit, and a second current terminal of the amplifier unit is coupled to the current source; and a driving unit having an output terminal coupled to a control terminal of the amplifier unit, wherein an input terminal of the driving unit is used to receive the first terminal signal in the differential input signal. A differential amplifier device as described in claim 4, wherein the amplifier unit comprises: a transistor, wherein a first end of the transistor is coupled to the second end of the load circuit, a second end of the transistor is coupled to the current source, a control end of the transistor is coupled to the output end of the driving unit, and the controller controls a channel width-to-length ratio of the transistor. The differential amplifier device as described in claim 4, wherein the driving unit includes: a buffer, wherein an output end of the buffer is coupled to the control end of the amplifier unit, an input end of the buffer is used to receive the first end signal in the differential input signal, and the controller controls a gain of the buffer. A differential amplifier device as described in claim 2, wherein the second current terminal of the amplifier circuit of the first-end signal circuit is coupled to a second current terminal of an amplifier circuit of the second-end signal circuit. The differential amplifier device as described in claim 7 further includes: a resistor, wherein a first end of the resistor is coupled to the second current end of the amplifier circuit of the first-end signal circuit, and a second end of the resistor is coupled to the second current end of the amplifier circuit of the second-end signal circuit. The differential amplifier device as described in claim 1 further includes: a resistor, wherein a first end of the resistor is coupled to a first output end of the first-end signal circuit, and a second end of the resistor is coupled to a second output end of the second-end signal circuit. The differential amplifier device as described in claim 1, wherein, in response to the transmission path attenuating the first end signal of the transmitted differential signal more than the transmission path attenuating the second end signal of the transmitted differential signal, the controller reduces a first current value of a first current source of the first end signal circuit, or the controller reduces a first gain of a first amplifier circuit of the first end signal circuit, or the controller reduces a first impedance of a first load circuit of the first end signal circuit, or the controller reduces the first current value and the first gain, or the controller reduces the first gain and the first impedance, or the controller reduces the first current value, the first gain and the first impedance; and in response to the transmission path attenuating the first end signal of the transmitted differential signal less than the transmission path attenuating the second end signal of the transmitted differential signal, the controller reduces a second current value of a second current source of the second end signal circuit, or the controller reduces a second gain of a second amplifier circuit of the second end signal circuit, or the controller reduces a second impedance of a second load circuit of the second end signal circuit, or the controller reduces the second current value and the second gain, or the controller reduces the second gain and the second impedance, or the controller reduces the second current value, the second gain and the second impedance. A differential amplifier device as described in claim 1, wherein the first-end signal circuit comprises: a load circuit having a first end coupled to a first voltage, wherein a second end of the load circuit is coupled to an output end of the first-end signal circuit, and the output end provides the first-end signal; and an amplifier circuit having an input end for receiving a first-end signal in a differential input signal of the differential amplifier device, wherein a first current end of the amplifier circuit is coupled to the second end of the load circuit, wherein the at least one first component parameter comprises an impedance of the load circuit or a gain of the amplifier circuit. The differential amplifier device as described in claim 11 further includes: A current source coupled to a second current terminal of the amplifier circuit of the first-end signal circuit and a second current terminal of an amplifier circuit of the second-end signal circuit. A compensation method is provided for compensating for the asymmetric effect of a transmission path on a first-end signal and a second-end signal in a transmitted differential signal. The compensation method comprises: generating a first-end signal in a differential output signal to a first end of the transmission path by a first-end signal circuit of a differential amplifier device; generating a second-end signal in the differential output signal to the first end of the transmission path by a second-end signal circuit of the differential amplifier device, wherein the second-end signal circuit is coupled to the first-end signal circuit. signal circuit; and adjusting at least one first component parameter of the first-end signal circuit or at least one second component parameter of the second-end signal circuit based on the transmitted differential signal at a second end of the transmission path to compensate for the asymmetric effect of the transmission path on the first-end signal and the second-end signal of the transmitted differential signal, wherein the adjustment of the at least one first component parameter of the first-end signal circuit is independent of the adjustment of the at least one second component parameter of the second-end signal circuit. A compensation method as described in claim 12, wherein the first-end signal circuit includes a load circuit, an amplifier circuit and a current source, a first end of the load circuit is coupled to a first voltage, a second end of the load circuit is coupled to an output end of the first-end signal circuit, the output end provides the first-end signal, an input end of the amplifier circuit is used to receive a first-end signal in a differential input signal of the differential amplifier device, a first current end of the amplifier circuit is coupled to the second end of the load circuit, the current source is coupled to a second current end of the amplifier circuit, and the at least one first component parameter includes an impedance of the load circuit, a gain of the amplifier circuit or a current value of the current source. The compensation method as described in claim 13 further includes: in response to the attenuation of the first end signal of the transmitted differential signal by the transmission path being greater than the attenuation of the second end signal of the transmitted differential signal by the transmission path, reducing a first current value of a first current source of the first end signal circuit, or reducing a first gain of a first amplifier circuit of the first end signal circuit, or reducing a first impedance of a first load circuit of the first end signal circuit, or reducing the first current value and the first gain, or reducing the first gain and the first impedance, or reducing the first current value, the first gain, or ... and the first impedance; and in response to the transmission path attenuating the first end signal of the transmitted differential signal less than the transmission path attenuating the second end signal of the transmitted differential signal, reducing a second current value of a second current source of the second end signal circuit, or reducing a second gain of a second amplifier circuit of the second end signal circuit, or reducing a second impedance of a second load circuit of the second end signal circuit, or reducing the second current value and the second gain, or reducing the second gain and the second impedance, or reducing the second current value, the second gain and the second impedance. A compensation method as described in claim 12, wherein the first-end signal circuit includes a load circuit and an amplifier circuit, the first end of the load circuit is coupled to a first voltage, the second end of the load circuit is coupled to an output end of the first-end signal circuit, the output end provides the first-end signal, an input end of the amplifier circuit is used to receive a first-end signal in a differential input signal of the differential amplifier device, a first current end of the amplifier circuit is coupled to the second end of the load circuit, and the at least one first component parameter includes an impedance of the load circuit or a gain of the amplifier circuit.

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