Voltage monitoring

Abstract

Voltage Monitoring This description concerns a voltage adaptation circuit (400) of a first voltage (VBUS) received by a connector, adapted to provide a second voltage (VBUSMON) equal to: - the first voltage (VBUS), if the first voltage (VBUS) is less than a threshold voltage (Vth); or - the first voltage (VBUS) divided by a first coefficient, if the first voltage (VBUS) is greater than or equal to the threshold voltage (Vth). Figure for the abbreviation: Fig. 4

Description

Title of the invention: Monitoring of a voltage Technical field

[0001] The present description relates generally to electronic systems and devices, and more particularly to electronic systems and devices adapted to USB Type-C technology and the USB PD protocol. The present description relates more specifically to a part of a control circuit of a connector adapted to USB-C PD technology. Prior art

[0002] USB (Universal Serial Bus) technology is a computer bus standard used to connect all types of electronic devices together, allowing them to exchange data and / or energy. USB technology has evolved over time, and one of its latest versions, USB Type-C technology implementing the USB PD energy transfer protocol, has the ability to exchange higher powers, i.e., for example, powers greater than 100 W based on a voltage greater than 20 V.

[0003] It would be desirable to be able to improve, at least in part, certain aspects of electronic devices adapted to implement USB type C technology. Summary of the invention

[0004] There is a need for devices adapted to implement USB Type-C technology and the USB PD protocol adapted to receive a power greater than 100 W based on a voltage greater than 20 V.

[0005] There is a need for devices adapted to implement USB Type-C technology and the USB PD protocol adapted to receive a power of the order of 240 W based on a voltage of the order of 48 V.

[0006] There is a need for a circuit enabling devices adapted to implement USB type C technology and the already existing USB PD protocol to receive a power of the order of 240 W based on a voltage of the order of 48 V.

[0007] One embodiment overcomes all or part of the drawbacks of known devices adapted to implement USB type C technology.

[0008] One embodiment provides a voltage matching circuit for a first voltage received by a connector, adapted to provide a second voltage equal to: - the first voltage, if the first voltage is lower than a threshold voltage; or - the first voltage divided by a first coefficient, if the first voltage is greater than or equal to the threshold voltage.

[0009] According to one embodiment, the circuit comprises a first comparator circuit suitable for comparing the first voltage to the threshold voltage.

[0010] According to one embodiment, the circuit comprises a second voltage division circuit adapted to dividing the first voltage by the first coefficient.

[0011] According to one embodiment, said second circuit comprises a voltage divider bridge.

[0012] According to one embodiment, the first coefficient is of the order of 3.

[0013] According to one embodiment, the circuit comprises a third selection circuit adapted to connect a node providing the second voltage either to a node providing the first voltage, or to a node providing the first voltage divided by the first coefficient.

[0014] According to one embodiment, the third circuit is controlled by an output voltage of the first circuit.

[0015] According to one embodiment, the third circuit is, in addition, controlled by a control voltage.

[0016] According to one embodiment, the control voltage is a voltage indicating whether the connector is supposed to receive a first voltage greater than the threshold voltage or not.

[0017] According to one embodiment, the connector is adapted to USB type C technology and to the USB PD protocol.

[0018] Another embodiment provides an electronic connector device comprising the voltage matching circuit described above.

[0019] According to one embodiment, the circuit further comprises a monitoring circuit receiving the second voltage supplied by said voltage adaptation circuit.

[0020] According to one embodiment, the monitoring circuit is adapted to monitor a voltage lower than 20 V.

[0021] According to one embodiment, the electronic device further comprises a connector.

[0022] Another embodiment provides a method of monitoring a first voltage received by a connector, wherein a second monitoring voltage is provided, the second monitoring voltage being equal to: - the first voltage, if the first voltage is less than a threshold voltage; or - to the first voltage divided by a first coefficient, if the first voltage is greater than or equal to the threshold voltage. Brief description of the drawings

[0023] These characteristics and advantages, as well as others, will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:

[0024] [Fig.l] represents, very schematically and in the form of blocks, an example of a USB type C connection between two electronic devices;

[0025] [Fig.2] represents a graph illustrating, for a given power, the different voltage / current pairs, which can be transferred using USB type C technology and the USB PD protocol;

[0026] [Fig.3] represents a very schematic view of a connector adapted to USB type C technology and the USB PD protocol.

[0027] [Fig.4] represents, very schematically and in the form of blocks, an embodiment of a voltage monitoring circuit;

[0028] [Fig.5] shows a more detailed embodiment of a voltage monitoring circuit; and

[0029] [Fig.6] shows graphs illustrating the operation of the embodiment of [Fig.4]. Description of the embodiments

[0030] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0031] For the sake of clarity, only the steps and elements useful for understanding the embodiments described have been shown and are detailed. In particular, the different data exchange protocols used with the connectors of the embodiments described below are not described in detail, these protocols being, for the majority, compatible with the embodiments described.

[0032] Unless otherwise specified, when referring to two elements connected to each other, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") to each other, this means that these two elements can be connected or be connected by means of one or more other elements.

[0033] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made unless otherwise specified to the orientation of the figures.

[0034] Unless otherwise specified, the expressions "about", "approximately", "substantially", and "of the order of" mean to within 10%, preferably to within 5%.

[0035] [Fig.l] represents, very schematically and in the form of blocks, two electronic devices 101 and 102 connected to each other by a connection cable 103.

[0036] The devices 101 and 102 are, according to the example described in relation to [Fig.l], respectively, each equipped with a connector 101C, 102C. The connection cable 103 is equipped, at each of its ends, with connectors 104 adapted to cooperate with the connectors 101C and 102C of the devices 101 and 102. According to one example, the connectors 104 are male type connectors, and the connectors 101C and 102C are female type connectors. According to a variant, the connectors 104 are female type connectors, and the connectors 101C and 102C are male type connectors.

[0037] According to yet another variant, the devices 101 and 102 can be connected without a connection cable. In this case, the connector 101C, or conversely the connector 102C, is a male type connector, and the connector 102C, or conversely the connector 10IC, is a female type connector.

[0038] The connectors 101C, 102C and 104 are, in general, all formed of mechanical connection means, and one or more circuits adapted to implement the electronic connection.

[0039] According to one embodiment, the cable 103 and the connectors 101C, 102C and 104 are adapted to implement the USB (Universal Serial Bus) technology allowing the exchange of data but also energy. The USB technology is defined by a serial computer bus standard. Several types of USB technology exist, the cable 103 and the connectors 101C, 102C, and 104 are, more particularly, adapted to implement a USB type C technology. The particularity of the USB type C technology is that it allows the exchange of powers of more than 100 W, and up to 240 W between two electronic devices. In addition, the USB type C technology can allow the implementation of the USB PD protocol, also called USB Power Delivery protocol, which is an energy exchange protocol. This protocol is described in more detail in relation to [Fig.2].

[0040] [Fig.2] is a graph illustrating the operation of the USB PD energy exchange protocol, and more particularly, illustrating the different voltage / current pairs defined by a standard, for a given power, which can be transferred using USB type C technology and the USB PD protocol.

[0041] The USB PD protocol makes it possible to manage the exchange of energy between two devices connected by a USB type C cable, and makes it possible, more particularly, to manage the level of the electrical power exchanged. More particularly, the electronic devices using this protocol are adapted to provide, at their connector, several different current values ​​and several different voltage values. These different current and voltage values ​​are defined, for example, by manufacturing according to the components of the devices, and / or, for example, the operating modes of the device. The different current values ​​that can be provided by a device implementing this protocol, may, for example, be chosen from the group comprising: 1.5 A, 2 A, 3 A, and 5 A. The different voltage values ​​that can be provided by a device implementing this protocol, may, for example, be chosen from the group comprising: 5 V, 9 V, 12 V, 15 V, 20 V, 28 V, 36 V, and 48 V. A power value provided by a device is defined by a pair comprising a current value and a voltage value. Such a pair is subsequently called a power profile.

[0042] The graph in [Fig.2] illustrates examples of possible power profiles with the USB PD protocol. Reading a power value on the abscissa makes it possible to determine the voltage / current pair defined by the standard allowing this power to be obtained. The graph includes several curves, each representing, for a given voltage value, the evolution of the electrical power transferred as a function of the current that can be supplied at this voltage value. More specifically, the graph illustrates seven curves, including: - a curve 201 representing, for a voltage of the order of 5 V, an electrical power supplied of between 0 W and 15 W, with, consequently, a current varying between 0 and 3 A; - a curve 202 representing, for a voltage of the order of 9 V, an electrical power supplied of between 15 W and 27 W, with, consequently, a current varying between 1.6 and 3 A; - a curve 203 representing, for a voltage of the order of 15 V, an electrical power supplied of between 27 W and 45 W, with, consequently, a current varying between 1.8 and 3 A; - a curve 204 representing, for a voltage of the order of 20 V, an electrical power supplied of between 45 W and 100 W, with, consequently, a current varying between 2.25 and 5 A; - a curve 205 representing, for a voltage of the order of 28 V, an electrical power supplied of between 100 W and 140 W, with, consequently, a current varying between 3.6 and 5 A; - a curve 206 representing, for a voltage of the order of 36 V, an electrical power supplied of between 140 W and 180 W, with, consequently, a current varying between 3.8 and 5 A; and - a curve 207 representing, for a voltage of the order of 48 V, an electrical power supplied of between 180 W and 240 W, with, consequently, a current varying between 3.75 and 5 A.

[0043] When an electrical device is capable of providing one of the power supply profiles of curves 201 to 207 providing an electrical power PI, it is also capable of providing all the power supply profiles corresponding to electrical powers in lower than this electrical power PI. According to a practical example, if an electronic device is capable of providing the power profile providing a power of 45 W of curve 203, that is to say the power profile providing the current 15 V / 3 A, it is also capable of providing the power profiles providing the powers of 7.5 W of curve 201, 15 W of curve 202 and 27 W of curve 203.

[0044] The power supply profiles illustrated with curves 201 to 204, i.e. the voltage / current pairs and the associated powers of curves 201 to 204, are part of a first SPR power supply domain, or SPR standard domain, corresponding to the standard power supply profiles (Standard Power Range) of the devices adapted to implement the USB PD protocol. These power supply profiles are part of those envisaged in a first and older version of the USB PD protocol. Other power supply profiles characterized by a transmitted power of less than 100 W, or a voltage of less than 20 V, may be part of the first SPR power supply domain.

[0045] The power supply profiles illustrated with curves 205 to 207, i.e. the voltage / current pairs and the associated powers of curves 205 to 207, are part of a second EPR power supply domain, or extended EPR domain, corresponding to the extended power supply profiles (Extended Power Range) of the devices adapted to implement the USB PD protocol. These power supply profiles are part of those envisaged in a second version of the USB PD protocol, corresponding to an extension of the first version. Other power supply profiles characterized by a transmitted power greater than 100 W, and up to 240 W, or a voltage greater than 20 V, may be part of the extended EPR power supply domain.

[0046] In practice, when two devices K1 and K2 adapted to USB type C technology and the USB PD protocol are connected together, a power supply, or where appropriate a charging, of the device K1 by the device K2 takes place in the following manner. The devices K1 and K2 begin by reporting the power supply profiles that they are capable of supplying and receiving. A negotiation follows between the devices K1 and K2 to determine which power supply profile is suitable for powering the device KL. Once the power supply profile has been chosen, the device K2 sends the current-voltage pair characterizing said power supply profile, and the power supply, or charging where appropriate, of the device K1 is carried out.

[0047] [Fig. 3] represents, very schematically and in the form of blocks, an embodiment of a module 300 associated with a connector adapted to USB type C technology and to the USB PD protocol, of the type of connectors 101C or 102C described in relation to [Fig. 1].

[0048] The module 300 receives, as input, a VBUS voltage coming, for example, from a cable of the type of cable 103 described in relation to [Fig.l]. According to an example, the VBUS voltage can also correspond to a voltage supplied by the electronic device comprising the module 300 to a cable of the type of cable 103.

[0049] The module 300 comprises, on a first monitoring branch, a voltage adaptation circuit 301 (ADAPT) and a monitoring circuit 302 (MON). The voltage adaptation circuit receives, as input, the VBUS voltage and provides, as output, a VBUSMON voltage to the monitoring circuit 302. Detailed examples of circuit 301 are described in relation to FIGS. 4 to 6. The monitoring circuit 302 is adapted to monitor the VBUSMON voltage, which is a voltage representative of the VBUS voltage, to implement the USB PD protocol.

[0050] [Fig.4] represents, very schematically and in block form, a voltage adaptation circuit 400 of the type of circuit 301 described in relation to [Fig.3].

[0051] The circuit 400 receives, as input, the VBUS voltage, and provides, as output, the VBUSMON voltage. The VBUS voltage is a voltage provided by a power transfer cable adapted to USB type C technology and the USB PD protocol. According to one example, the VBUS voltage may also correspond to a voltage provided by the electronic device comprising the module 300 to a cable of the cable type 103. The VBUSMON voltage is a voltage representative of the VBUS voltage.

[0052] The circuit 400 further receives a threshold voltage Vth, and a control voltage EPR_ON, or control signal EPR_ON. For example, the threshold voltage Vth is between 10 and 20 V, for example of the order of 15 V. The voltage EPR_ON indicates whether the power supply profile that has been negotiated is part of the standard SPR domain or the extended EPR domain. In other words, the voltage EPR_ON indicates whether the connector and the module comprising the circuit 400 is supposed to receive a VBUS voltage greater than the threshold voltage Vth. According to one example, when the voltage EPR_ON is in a high state, the power supply profile is part of the extended EPR domain, and when the voltage EPR_ON is in a low state, the power supply profile is part of the standard SPR domain, or vice versa. According to one example, the voltage EPR_ON is generated and / or supplied by a processor internal or external to the module comprising the circuit 400.

[0053] The circuit 400 comprises a circuit 401 (COMP) for comparing two voltages. The circuit 401 receives, as input, the voltage VBUS and the threshold voltage Vth, and provides, as output, a voltage VComp, or a signal VComp, indicating the result of the comparison of the voltage VBUS and the threshold voltage Vth.

[0054] The circuit 400 further comprises a voltage division circuit 402 ( / n). The circuit 402 receives, as input, the voltage VBUS, and provides, as output, a voltage VBUSn equal to the voltage VBUS divided by a coefficient n. The coefficient n is dimensioned so that the voltage VBUSn is lower than a maximum voltage Vmax that can receive a monitoring circuit with which the circuit 400 is associated, that is to say a circuit of the type of circuit 302 described in relation to [Fig. 3]. According to an example, if the monitoring circuit is only adapted to monitor the VBUS when a power supply profile of the standard domain is used, the voltage Vmax is between 20 and 30 V, for example of the order of 28 V. According to an example, the coefficient n is between 2 and 5, for example of the order of 3. According to an example, the circuit 400 comprises a voltage divider bridge.

[0055] The circuit 400 further comprises, finally, a selection circuit 403 (SEL). The circuit 403 provides, as output, the voltage VBUSMON, and receives, as input, the voltages VBUS and VBUSn. The circuit 403 is, furthermore, controlled by the voltage VComp and the voltage EPR_ON.

[0056] The operation of the circuit 400 is as follows. When the USB PD protocol is implemented, and the VBUS voltage is present, the comparison circuit 401 compares the VBUS and Vth voltages. If the VBUS voltage is lower than the Vth voltage, the power supply profile implemented is part of the standard SPR domain. If the VBUS voltage is higher than the Vth voltage, it is possible that the power supply profile implemented is part of the extended EPR domain. The VComp voltage indicates the result of the comparison, for example by a high state when the VBUS voltage is higher than the threshold voltage Vth and by a low state when the VBUS voltage is lower than the threshold voltage Vth, or vice versa. In parallel, the VBUSn voltage, corresponding to the VBUS voltage divided by the coefficient n, is generated by the circuit 402.Alternatively, circuit 402 may also be activated by comparison voltage VComp, and only provide voltage VBUSn when necessary.

[0057] The selection circuit 403 is adapted to provide the VBUSMON voltage at the output, and this VBUSMON voltage is equal to: - to the VBUS voltage, when the result of the comparison indicates that the VBUS voltage is lower than the Vth voltage; or - at the VBUSn voltage, when the result of the comparison indicates that the VBUS voltage is higher than the Vth voltage, and the EPR_ON voltage indicates that the power supply profile implemented is part of the EPR extended domain.

[0058] An advantage of the circuit 400 is that it allows the VBUS voltage level to be adapted so that a power supply profile of the extended domain is monitored by a monitoring circuit adapted only to monitoring the power supply profile of the standard domain. Thus, it is possible to add a circuit of the type of the circuit 400 to modules adapted only to the standard domain.

[0059] [Fig. 5] shows, in more detail, an embodiment of a voltage adaptation circuit 500 of the type of circuit 400 described in relation to [Fig. 4]. In other words, circuit 500 is a detailed example of embodiment of circuit 400 of the [Fig.4].

[0060] Like the circuit 400 described in relation to [Fig.4], the circuit 500 comprises: - a comparison circuit 501 (COMP), of the type of the circuit 401 described in relation to [Fig.4]; - a voltage division circuit 502 ( / n), of the type of circuit 402 described in relation to [Fig.4]; and - a selection circuit 503 (SEL), of the type of circuit 403 described in relation to [Fig.4],

[0061] The comparison circuit 501 comprises two transistors T1 and T2, two diodes DZ1 and D2, and a resistor RL

[0062] Transistors T1 and T2 are insulated gate field effect transistors, or metal-oxide-semiconductor field effect transistors, hereinafter called MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistors or MOS transistors. In addition, transistors T1 and T2 are P-channel MOS transistors, or P-type MOS transistors, or PMOS transistors. Furthermore, N-channel MOS transistors are hereinafter called N-type MOS transistors, or NMOS transistors. The drain of transistor T1 is connected, preferably connected, to a node receiving voltage VBUS, and the source of transistor T1 is connected, preferably connected, to the source of transistor T2. The drain of transistor T2 is connected, preferably connected, to a node A. The gates of transistors T1 and T2 are connected to each other and to a node B.

[0063] Diodes DZ1 and DI are connected in series head to tail between the drain of transistor T1, or the drain of transistor T2, and node B. More particularly, the cathode of diode DZ1 is connected, preferably connected, to the drain of transistor T1, and the anode of diode DZ1 is connected, preferably connected, to the anode of diode D2. The cathode of diode D2 is connected, preferably connected, to node B. In addition, diode DZ1 is a Zener diode.

[0064] Resistor RI connects node B to a node receiving threshold voltage Vth. According to one example, resistor RI has a resistance of 100 kOhm.

[0065] The voltage division circuit 502 comprises two resistors R2 and R3, a transistor T3, and a diode D2.

[0066] Resistors R2 and R3 are connected in series between a node C and the anode of diode D2. According to one example, resistor R2 has a resistance of 20 kOhm, and resistor RI 1 has a resistance of 10 kOhm.

[0067] Diode D2 has its cathode connected, preferably connected, to a GND node, symbolized by a triangle in [Fig.5] and receiving a reference voltage, for example, ground.

[0068] Transistor T3 is a bipolar transistor of the NPN type. The gate of transistor T3 is connected, preferably connected, to the middle node between resistors R2 and R3. The emitter of transistor T3 is connected, preferably connected, to the node providing the VBUSMON voltage, and the collector of transistor T3 is connected, preferably connected, to node C. Transistor T3 is optional, and has a current source buffer role.

[0069] The coefficient n of the circuit 502 is defined by the ratio of the sum of the resistances of the resistors R2 and R3, by the resistance of the resistor R3. According to one example, the coefficient n is equal to 3.

[0070] The selection circuit 503 comprises four transistors T4, T5, T6 and T7, seven resistors R4, R5, R6, R7, R8, R9, and RIO, and three Zener diodes DZ2, DZ3, DZ4.

[0071] Transistor T4 is a P-type MOS transistor. The drain of transistor T4 is connected, preferably connected, to node C, and the source of transistor T4 is connected, preferably connected, to the node receiving the voltage VBUS. The gate of transistor T4 is connected, preferably connected, to a node D.

[0072] Resistor R4 and diode DZ2 are connected in parallel between node D and the node receiving the voltage VBUS. More particularly, the anode of diode DZ2 is connected, preferably connected, to node D, and the cathode of diode DZ2 is connected, preferably connected, to the node receiving the voltage VBUS. According to one example, resistor R5 has a resistance of the order of 100 kOhm.

[0073] Resistor R5 and transistor T5 are connected in series between node D and node GND. Transistor T5 is an N-type MOS transistor. More particularly, a first terminal of resistor R5 is connected, preferably connected, to node D, and a second terminal of resistor R5 is connected, preferably connected to the drain of transistor T5. The source of transistor T5 is connected, preferably connected, to node GND. The gate of transistor T5 is connected, preferably connected to a node E. According to one example, resistor R5 has a resistance of the order of 10 kOhm.

[0074] Resistor R6 and diode DZ3 are connected in parallel between node E and node GND. More particularly, the anode of diode DZ3 is connected, preferably connected, to node GND, and the cathode of diode DZ3 is connected, preferably connected, to node E. According to one example, resistor R6 has a resistance of the order of 100 kOhm.

[0075] Resistor R7 connects nodes E and A. According to one example, resistor R7 has a resistance of the order of 10 kOhm.

[0076] Transistor T6 is a P-type MOS transistor, which connects the node receiving the VBUS voltage to the node supplying the VBUSMON voltage. More particularly, the drain of transistor T6 is connected, preferably connected, to the node supplying the VBUSMON voltage. The source of transistor T6 is connected, preferably connected, to the node receiving the VBUS voltage. Resistor R8 connects the gate of transistor T6 to node A. According to one example, resistor R8 has a resistance of the order of 10 kOhm. Diode DZ4 connects the gate of transistor T6 to its source. More particularly, the anode of diode DZ4 is connected, preferably connected, to the gate of transistor T8, and the cathode of diode DZ4 is connected, preferably connected, to the source of transistor T6.

[0077] Transistor T7 is an N-type MOS transistor. The drain of transistor T7 is connected, preferably connected, to the node receiving the threshold voltage, and the source of transistor T7 is connected, preferably connected, to the GND node. The gate of transistor T7 is connected, preferably connected, to the node receiving the EPR_ON voltage. Resistor R8 connects the gate of transistor T7 to the GND node. According to one example, resistor R8 has a resistance of the order of 100 kOhm.

[0078] The circuit 500 further comprises, optionally, a protection circuit 504, comprising a diode DZ5 and a resistor R9. The diode Z5 is a Zener diode connecting the node receiving the threshold voltage Vth to the GND node. More particularly, the cathode of the diode DZ5 is connected, preferably connected, to the node receiving the threshold voltage Vth, and the anode of the diode DZ5 is connected, preferably connected, to the GND node. The resistor R9 connects the node receiving the voltage Vth to the node receiving the voltage VBUS.

[0079] The function of the circuit 500 is to control the selection circuit in the case where the VBUS voltage is higher than the threshold voltage Vth, and the EPR_ON voltage indicates that a standard domain power supply profile is used. The circuit 500 therefore makes it possible to protect the monitoring circuit of the type of circuit 302 described in relation to [Fig.3], against an abnormal increase in the VBUS voltage.

[0080] The circuit 500 further comprises a filtering capacitor C1 connecting the node receiving the voltage VBUS to the node GND. According to one example, the capacitor C1 has a capacity of the order of 10 pF.

[0081] The circuit 500 further comprises, finally, a resistor RIO connecting the node supplying the voltage VBUSMON to the node GND. According to one example, the resistor RIO has a resistance of the order of 40 kOhm.

[0082] Diodes D1, DZ1, DZ2, and DZ3 are protection diodes.

[0083] The operation of the circuit 500 is described in relation to [Fig.6].

[0084] [Fig.6] comprises two graphs (A) and (B) illustrating, respectively, the time evolution of the VBUS voltage and the VBUSMON voltage. In this example, the threshold voltage Vth is of the order of 20 V.

[0085] Between an initial instant t0 and an instant t1, the VBUS voltage varies between 0 and Vth, i.e. 20 V in the example illustrated in [Fig.6]. The VBUSMON voltage follows the evolution of the VBUS voltage, and is equal to the VBUS voltage.

[0086] From time t1, and up to time t2, the voltage VBUS exceeds the threshold voltage Vth, and the voltage VBUSMON decreases to reach the level of the voltage VBUSn. In the case illustrated here, the coefficient n is of the order of 3.

[0087] After time t2, the VBUS voltage is lower than the threshold voltage Vth, and the VBUS voltage increases to return to the VBUS voltage level.

[0088] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will occur to those skilled in the art.

[0089] Finally, the practical implementation of the embodiments and variants described is within the reach of those skilled in the art from the functional indications given above.

Claims

Claims

1. Voltage adaptation circuit (301; 400; 500) of a first voltage (VBUS) received by a connector (101C, 102C), adapted to provide a second voltage (VBUSMON) equal to: - the first voltage (VBUS), if the first voltage (VBUS) is lower than a threshold voltage (Vth); or - to the first voltage (VBUS) divided by a first coefficient (n), if the first voltage (VBUS) is greater than or equal to the threshold voltage (Vth).

2. Circuit according to claim 1, comprising a first comparator circuit (401; 501) adapted to compare the first voltage (VBUS) with the threshold voltage (Vth).

3. Circuit according to claim 1 or 2, comprising a second voltage division circuit (402; 502) adapted to divide the first voltage (VBUS) by the first coefficient (n).

4. The circuit of claim 3, wherein said second circuit (402; 502) comprises a voltage divider bridge (R2, R3).

5. Circuit according to claim 3 or 4, in which the first coefficient (n) is of the order of 3.

6. Circuit according to any one of claims 1 to 5, comprising a third selection circuit (403; 503) adapted to connect a node supplying the second voltage (VBUSMON) either to a node supplying the first voltage (VBUS), or to a node supplying the first voltage (VBUS) divided by the first coefficient (n).

7. Circuit according to claim 6, wherein the third circuit (403; 503) is controlled by an output voltage (VComp) of the first circuit (401; 501).

8. Circuit according to claim 6 or 7, in which the third circuit (403; 503) is, in addition, controlled by a control voltage (EPR_ON).

9. A circuit according to claim 8, wherein the control voltage (EPR_ON) is a voltage indicating whether the connector is supposed to receive a first voltage greater than the threshold voltage or not.

10. Circuit according to any one of claims 1 to 9, wherein the connector (101C, 102C) is adapted to USB type C technology and to the USB PD protocol.

11. Electronic device (101, 102) comprising the matching circuit of voltage (301; 400; 500) according to any one of claims 1 to 10

12. IV. Electronic device according to claim 11, further comprising a monitoring circuit (302) receiving the second voltage (VBUSMON) provided by said voltage adaptation circuit (301; 400; 500).

13. An electronic device according to claim 12, wherein the monitoring circuit (302) is adapted to monitor a voltage less than 20 V.

14. A device (101, 102) according to any one of claims 11 to 13, further comprising a connector (101C, 102C, 104).

15. Method for monitoring a first voltage (VBUS) received by a connector (101C, 102C), in which a second monitoring voltage (VBUSMON) is provided, the second monitoring voltage (VBUSMON) being equal to: - the first voltage (VBUS), if the first voltage (VBUS) is lower than a threshold voltage (Vth); or - the first voltage (VBUS) divided by a first coefficient (n), if the first voltage (VBUS) is greater than or equal to the threshold voltage (Vth).

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