OVER-VOLTAGE PROTECTION SYSTEMS AND METHODS
20170346240 · 2017-11-30
Inventors
- Hector Ivan Oporta (San Jose, CA, US)
- Shashank Prakash Mane (San Jose, CA, US)
- Thomas O'Brien (Powell, OH, US)
- Christian Gregory Sporck (Campbell, CA, US)
Cpc classification
G06F13/4022
PHYSICS
H01L27/0248
ELECTRICITY
G06F13/385
PHYSICS
H01L27/0629
ELECTRICITY
H02H9/046
ELECTRICITY
H05K9/0067
ELECTRICITY
H01R24/60
ELECTRICITY
International classification
H01R13/66
ELECTRICITY
H01R24/60
ELECTRICITY
H01L27/06
ELECTRICITY
H01L27/02
ELECTRICITY
Abstract
Over-voltage protection systems and methods are disclosed. In one aspect, a biasing circuit is added to a pre-existing clamp required by the Universal Serial Bus (USB) Type-C specification at a configuration control (CC) pin. The biasing circuit turns the pre-existing clamp into an adjustable clamp that dynamically adjusts to over-voltage conditions. In an exemplary aspect, the biasing circuit may include a biasing field effect transistor (FET) and a pair of switches that selectively couple the pre-existing clamp and the biasing FET to fixed voltages such that the CC pin is maintained at an acceptable voltage. In another exemplary aspect, the biasing circuit may omit the biasing FET and rely on two switches that selectively couple the pre-existing clamp to fixed voltages such that the CC pin is maintained at an acceptable voltage.
Claims
1. A device, comprising: a Universal Serial Bus (USB) receptacle configured to receive a USB cable, the USB receptacle comprising a configuration control (CC) pin; a first field effect transistor (FET) comprising a first source, a first drain, and a first gate, the first source coupled to the CC pin and the first drain coupled to ground; a second FET comprising a second source, a second drain, and a second gate, the second gate coupled to the first gate and to the second drain at a communal node; a first switch coupled to the second source and selectively coupling the second source to an internal voltage source (Vaa); and a second switch coupled to the communal node and selectively coupling the communal node to an external voltage source (Vconn); and wherein in a first mode of operation both the first switch and the second switch are open and the CC pin is clamped at a first Vgs above ground and wherein in a second mode of operation only one of the first switch and the second switch is open and the CC pin is clamped at a corresponding first voltage or second voltage.
2. The device of claim 1, wherein the first FET comprises a PMOS FET.
3. The device of claim 1, wherein the second FET comprises a PMOS FET.
4. The device of claim 1, wherein the USB receptacle is a USB Type-C receptacle.
5. The device of claim 1, further comprising a resistor coupled to the second drain and ground.
6. The device of claim 1, wherein Vgs of the first FET comprises a 1.1 volt difference.
7. The device of claim 1, wherein the internal voltage source is approximately 3.5 volts.
8. The device of claim 1, wherein the external voltage source is approximately 5 volts.
9. The device of claim 1, further comprising a control system operably coupled to the first switch and the second switch, the control system configured to open and close the first switch and the second switch.
10. The device of claim 9, wherein the control system is configured to detect a first resistance associated with the CC pin and a second resistance with a second CC pin and, based on the detected resistances, selectively enable the external voltage source.
11. The device of claim 10, wherein the control system is configured to open the first switch if the external voltage source is enabled.
12. The device of claim 10, wherein the control system is configured to open the second switch if the external voltage source is not enabled.
13. The device of claim 1, wherein the first voltage comprises the internal voltage source.
14. The device of claim 1, wherein the second voltage comprises the external voltage source plus Vgs of the first PET.
15. The device of claim 1 integrated into a device selected from the group consisting of: a set top box; an entertainment unit; a navigation device; a communications device; a fixed location data unit; a mobile location data unit; a mobile phone; a cellular phone; a smart phone; a tablet; a phablet; a server; a computer; a portable computer; a desktop computer; a personal digital assistant (PDA); a monitor; a computer monitor; a television; a tuner; a radio; a satellite radio; a music player; a digital music player; a portable music player; a digital video player; a video player; a digital video disc (DVD) player; a portable digital video player; and an automobile.
16. A device, comprising: a Universal Serial Bus (USB) receptacle configured to receive a USB cable, the USB receptacle comprising a configuration control (CC) pin; a first means for clamping coupled to the CC pin and coupled to ground; a second means for clamping coupled to the first means for clamping and to a communal node; a first switch coupled to the second means for clamping FET and selectively coupling the second means for clamping to an internal voltage source (Vaa); and a second switch coupled to the communal node and selectively coupling the communal node to an external voltage source (Vconn); and wherein in a first mode of operation both the first switch and the second switch are open and the CC pin is clamped at a first Vgs above ground and wherein in a second mode of operation only one of the first switch and the second switch is open and the CC pin is clamped at a corresponding first voltage or second voltage.
17. A method for protecting a pin on a Universal Serial Bus (USB) connector, comprising: providing biasing circuitry on a field effect transistor (FET) associated with a pin on a USB connector; clamping the pin at a first voltage if power is applied to a chip associated with the pin; and clamping the pin at one of a second voltage or a third voltage if power is not applied.
18. The method of claim 17, further comprising detecting if power is applied to the chip.
19. The method of claim 18, further comprising, if power is not applied to the chip, opening two switches of the biasing circuitry to clamp voltage at the pin at the first voltage.
20. The method of claim 18, further comprising detecting a resistance associated with the pin.
21. The method of claim 20, further comprising enabling or disabling an external voltage source based on the resistance detected.
22. The method of claim 20, further comprising opening one switch of two switches in the biasing circuitry based on the resistance detected.
23. The method of claim 18, wherein clamping the pin at one of the second voltage or the third voltage comprises clamping at an internal voltage or at a level associated with an external voltage source.
24. The method of claim 23, wherein clamping the pin at one of the second voltage or the third voltage comprises opening a first of two switches while closing a second of the two switches to clamp the pin at the second voltage and opening the second of the two switches while closing the first of the two switches to clamp the pin at the third voltage.
25. A device, comprising: a Universal Serial Bus (USB) receptacle configured to receive a connector of a USB cable, the USB receptacle comprising a configuration control (CC) pin; a first field effect transistor (FET) comprising a first source, a first drain, and a first gate, the first source coupled to the CC pin and the first drain coupled to ground; a first switch coupled to the first gate and selectively coupling the first gate to an internal voltage source (Vaa); and a second switch coupled to the first gate and selectively coupling the first gate to an external voltage source (Vconn); and wherein in a first mode of operation, both the first switch and the second switch are open and the CC pin is clamped at a first Vgs above ground and wherein in a second mode of operation, only one of the first switch and the second switch is open and the CC pin is clamped at a corresponding first voltage or second voltage.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0015]
[0016]
[0017]
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[0019]
[0020]
[0021]
[0022]
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[0024]
DETAILED DESCRIPTION
[0025] With reference now to the drawing figures, several exemplary aspects of the present disclosure are described. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.
[0026] Aspects disclosed in the detailed description include over-voltage protection systems and methods. In particular, exemplary aspects of the present disclosure add a biasing circuit to a pre-existing clamp required by the Universal Serial Bus (USB) Type-C specification at a configuration control (CC) pin. The biasing circuit turns the pre-existing clamp into an adjustable clamp that dynamically adjusts to over-voltage conditions. In an exemplary aspect, the biasing circuit may include a biasing field effect transistor (FET) and a pair of switches that selectively couple the pre-existing clamp and the biasing FET to fixed voltages such that the CC pin is maintained at an acceptable voltage. In another exemplary aspect, the biasing circuit may omit the biasing FET and rely on two switches that selectively couple the pre-existing clamp to fixed voltages such that the CC pin is maintained at an acceptable voltage. Still other biasing circuits may be used. The biasing circuits of the present disclosure are relatively small and cost effective to implement. Further, the biasing circuits do not require external components. Still further, if a PMOS biasing FET is used, there is no leakage current to interfere with any operational modes.
[0027] Before addressing the particulars of over-voltage protection systems and methods of the present disclosure, a brief overview of a computing system using a USB cable and a typical USB Type-C connector are discussed with reference to
[0028] In this regard,
[0029] With continued reference to
[0030]
TABLE-US-00001 TABLE 1 USB TYPE-C CONNECTOR PIN CONFIGURATION Number Pin Name Description 200(1) A1 GND Ground return 200(2) A2 SSTXp1 SuperSpeed differential pair #1, TX, positive 200(3) A3 SSTXn1 SuperSpeed differential pair #1, TX, negative 200(4) A4 V.sub.BUS Bus power 200(5) A5 CC1 Configuration Channel 200(6) A6 Dp1 USB 2.0 differential pair, position 1, positive 200(7) A7 Dn1 USB 2.0 differential pair, position 1, negative 200(8) A8 SBU1 Sideband Use (SBU) 200(9) A9 V.sub.BUS Bus power 200(10) A10 SSRXn2 SuperSpeed differential pair #2, RX, negative 200(11) A11 SSXp2 SuperSpeed differential pair #2, RX, positive 200(12) A12 GND Ground return 200(13) B1 GND Ground return 200(14) B2 SSTXp2 SuperSpeed differential pair #2, TX, positive 200(15) B3 SSTXn2 SuperSpeed differential pair #2, TX, negative 200(16) B4 V.sub.BUS Bus power 200(17) B5 CC2 Configuration Channel 200(18) B6 Dp2 USB 2.0 differential pair, position 2, positive 200(19) B7 Dn2 USB 2.0 differential pair, position 2, negative 200(20) B8 SBU2 Sideband use 200(21) B9 V.sub.BUS Bus power 200(22) B10 SSRXn1 SuperSpeed differential pair #1, RX, negative 200(23) B11 SSRXp1 SuperSpeed differential pair #1, RX, positive 200(24) B12 GND Ground return
[0031] It should be appreciated that a USB receptacle or port such as the USB Type-C port 118 has complementary conductive elements. In some exemplary aspects, such conductive elements are pins, and in others, such conductive elements are contact pads. As used herein, the conductive elements of the USB receptacle are referred to as pins regardless of the specific form they take. The form factor of the USB receptacle is defined in the USB specification and well understood at this point.
[0032] The USB specification further defines the use of certain resistors and their expected values in conjunction with a USB cable.
[0033] The USB Type-C specification further requires that CC pins (i.e., first CC pin 200(5) and second CC pin 200(17)) be held at five volts (5 V) to protect the circuitry within a computing device such as the second computing device 104 that is associated with the CC pins. However, there are situations where more than 5 V may be provided through the USB cable 106 from the Type-A end of the USB cable 106. Such high voltages may damage the circuitry within the second computing device 104 associated with the CC pins. Exemplary aspects of the present disclosure provide an elegant solution as described in greater detail below beginning with reference to
[0034] In this regard,
[0035] Additional detail about an exemplary aspect of the first adjustable clamp circuit 426 and the second adjustable clamp circuit 428 with their respective biasing circuitry is provided with reference to
[0036] Continuing the exemplary aspect of
[0037] With continued reference to
[0038] With continued reference to
[0039] It should be appreciated that use of PMOS FETs for the second FET 516 insures that there is little or no leakage current at the operating ranges. By eliminating leakage current, there should not be any errors in low current sensing or factory mode detection. Further, the biasing circuitry 500 is relatively simple and robust while consuming a relatively small amount of area. Still further, the use of the second FET 516 and the switches 530 and 532 consume relatively little current.
[0040]
[0041] With continued reference to
[0042] With continued reference to
[0043] While the present disclosure provides a simple, robust solution to provide over-voltage protection, there are other solutions. As noted, one solution already proposed is to use an external zener diode.
[0044] In
[0045]
[0046] The over-voltage protection systems and methods according to aspects disclosed herein may be provided in or integrated into any processor-based device. Examples, without limitation, include a set top box, an entertainment unit, a navigation device, a communications device, a fixed location data unit, a mobile location data unit, a global positioning system (GPS) device, a mobile phone, a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a tablet, a phablet, a server, a computer, a portable computer, a mobile computing device, a wearable computing device (e.g., a smart watch, a health or fitness tracker, eyewear, etc.), a desktop computer, a personal digital assistant (PDA), a monitor, a computer monitor, a television, a tuner, a radio, a satellite radio, a music player, a digital music player, a portable music player, a digital video player, a video player, a digital video disc (DVD) player, a portable digital video player, an automobile, a vehicle component, avionics systems, a drone, and a multicopter.
[0047] In this regard,
[0048] Other devices can be connected to the system bus 1008. As illustrated in
[0049] The CPU(s) 1002 may also be configured to access the display controller(s) 1020 over the system bus 1008 to control information sent to one or more displays 1026. The display controller(s) 1020 sends information to the display(s) 1026 to be displayed via one or more video processors 1028, which process the information to be displayed into a format suitable for the display(s) 1026. The display(s) 1026 can include any type of display, including, but not limited to, a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display, a light emitting diode (LED) display, etc.
[0050] Those of skill in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithms described in connection with the aspects disclosed herein may be implemented as electronic hardware, instructions stored in memory or in another computer readable medium and executed by a processor or other processing device, or combinations of both. The devices described herein may be employed in any circuit, hardware component, integrated circuit (IC), or IC chip, as examples. Memory disclosed herein may be any type and size of memory and may be configured to store any type of information desired. To clearly illustrate this interchangeability, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. How such functionality is implemented depends upon the particular application, design choices, and/or design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.
[0051] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).
[0052] The aspects disclosed herein may be embodied in hardware and in instructions that are stored in hardware, and may reside, for example, in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of computer readable medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a remote station. In the alternative, the processor and the storage medium may reside as discrete components in a remote station, base station, or server.
[0053] It is also noted that the operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. The operations described may be performed in numerous different sequences other than the illustrated sequences. Furthermore, operations described in a single operational step may actually be performed in a number of different steps. Additionally, one or more operational steps discussed in the exemplary aspects may be combined. It is to be understood that the operational steps illustrated in the flowchart diagrams may be subject to numerous different modifications as will be readily apparent to one of skill in the art. Those of skill in the art will also understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
[0054] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.