Patents Assigned to Coolstar Technology, Inc.
  • Patent number: 10826434
    Abstract: A semiconductor device includes at least one RF power amplifier (RFPA) and a voltage supply adjustment network coupled with the RFPA for providing an internal supply voltage to the RFPA based on an applied input voltage. The voltage supply adjustment network includes multiple resistors, multiple Zener diodes, a voltage return connection, an internal supply voltage connection coupled with the RFPA for conveying the supply voltage to the RFPA, an input voltage connection adapted to receive the input voltage, and a configurable connection network coupled with the resistors and Zener diodes. A subset of the resistors and Zener diodes are selectively connected together between the input voltage and the voltage return connections via corresponding conductive links to provide a prescribed output voltage to the internal supply voltage connection as a function of the applied input voltage. The connection network is configured by applying an energy source to a selected conductive link(s) in the connection network.
    Type: Grant
    Filed: April 2, 2019
    Date of Patent: November 3, 2020
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventors: Yi Zheng, Xiaotong Lin
  • Patent number: 10826291
    Abstract: An ESD power clamp circuit includes first, second and third timing networks, first and second NMOS transistors and an enable circuit. The first timing network has a first time constant and detects a voltage transient between first and second voltage supply nodes having a rise time less than the first time constant. The first NMOS transistor has a gate connected with an output of the first timing network and a source connected with a gate of the second NMOS transistor. The second NMOS transistor has a drain connected with the first voltage supply node and a source connected with the second voltage supply node. The second timing network is coupled with the gate of the second NMOS transistor and has a second time constant that is greater than a duration of an ESD event. The third timing network is coupled with the enable circuit and has a third time constant, the third timing network generating a first control signal based on the third time constant.
    Type: Grant
    Filed: September 12, 2018
    Date of Patent: November 3, 2020
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventor: Jessel T. Xavier
  • Patent number: 10735044
    Abstract: An integrated front-end module (FEM) includes at least one power amplifier (PA) coupled to an antenna without inclusion of a switching element in a transmit signal path in the FEM between an output of the PA and the antenna. The FEM further includes at least one low-noise amplifier (LNA) and a switching circuit coupled in a receive signal path of the FEM between the antenna and an input of the LNA. The switching circuit is configured in a first mode to disable the PA and to connect the input of the LNA to the antenna for receiving signals from the antenna. The switching circuit is configured in a second mode to disconnect the input of the LNA from the antenna and to enable the PA for transmitting signals to the antenna.
    Type: Grant
    Filed: July 20, 2018
    Date of Patent: August 4, 2020
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventor: Shuming Xu
  • Patent number: 10566270
    Abstract: A semiconductor device having enhanced thermal transfer includes at least one die, including a device layer in which one or more functional circuit elements are formed and a substrate supporting the device layer, and a support structure. The die is disposed on the support structure using at least one connection structure coupled between the device layer and the support structure. A back surface of the substrate is textured so as to increase a surface area of the back surface to thereby enhance thermal transfer between the substrate and an external environment.
    Type: Grant
    Filed: September 5, 2018
    Date of Patent: February 18, 2020
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventors: Shuming Xu, Yi Zheng
  • Patent number: 10340790
    Abstract: An exemplary voltage correction circuit includes a high-pass filter coupled with an integrated load, and an active clamp coupled with the high-pass filter in a closed-loop feedback arrangement. The high-pass filter includes an impedance network having a frequency response defining a lower frequency boundary of a passband of the voltage correction circuit, and the active clamp has a frequency response defining an upper frequency boundary of the passband of the voltage correction circuit. The active clamp is adapted to receive an input voltage proportional to a load transient within the passband and to generate an output current of the voltage correction circuit that cancels the effects of the load transient. A loop gain of the voltage correction circuit is greater than or equal to one within the passband and is less than one for frequencies lower than the lower frequency boundary and higher than the upper frequency boundary.
    Type: Grant
    Filed: September 18, 2018
    Date of Patent: July 2, 2019
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventor: James Andrew Akio Yasuhara
  • Patent number: 10236288
    Abstract: A power semiconductor device includes a substrate of a first conductivity type, a buried layer of a second conductivity type formed in at least a portion of the substrate, and at least one epitaxial layer of the first conductivity type formed on at least a portion of an upper surface of the substrate and covering the buried layer. The epitaxial layer and the buried layer form a junction capacitor. The device further includes at least one active power transistor formed in an upper surface of the epitaxial layer and above at least a portion of the buried layer.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: March 19, 2019
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventor: Shuming Xu
  • Patent number: 10224268
    Abstract: A semiconductor device having enhanced thermal transfer includes at least one die, including a device layer in which one or more functional circuit elements are formed and a substrate supporting the device layer, and a support structure. The die is disposed on the support structure using at least one connection structure coupled between the device layer and the support structure. A back surface of the substrate is textured so as to increase a surface area of the back surface to thereby enhance thermal transfer between the substrate and an external environment.
    Type: Grant
    Filed: November 28, 2016
    Date of Patent: March 5, 2019
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventors: Shuming Xu, Yi Zheng
  • Patent number: 10141271
    Abstract: A method of reducing electromagnetic interference in a semiconductor device includes: forming at least one functional circuit in a substrate of the semiconductor device; forming an integrated micro-shielding structure in the semiconductor device, the micro-shielding structure extending vertically through the substrate between a front surface and a back surface of the substrate and surrounding the functional circuit, the micro-shielding structure being configured to reduce radio frequency (RF) emissions in the semiconductor device and/or RF coupling between different functional parts of the functional circuit.
    Type: Grant
    Filed: March 17, 2017
    Date of Patent: November 27, 2018
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventors: Shuming Xu, Yi Zheng
  • Patent number: 10134641
    Abstract: A method of fabricating a power semiconductor device includes: forming at least one lateral diffused metal-oxide-semiconductor (LDMOS) structure having a first fully silicided gate including a first metal silicide material; and forming at least one complementary metal-oxide-semiconductor (CMOS) structure integrated with the LDMOS structure on a same substrate, the CMOS structure having a second fully silicided gate including a second metal silicide material. The first metal silicide material preferably includes tungsten silicide and the second metal silicide material includes a material other than tungsten silicide.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: November 20, 2018
    Assignee: COOLSTAR TECHNOLOGY, INC.
    Inventor: Shuming Xu
  • Patent number: 10116347
    Abstract: An integrated front-end module (FEM) includes at least one power amplifier (PA) coupled to an antenna without inclusion of a switching element in a transmit signal path in the FEM between an output of the PA and the antenna. The FEM further includes at least one low-noise amplifier (LNA) and a switching circuit coupled in a receive signal path of the FEM between the antenna and an input of the LNA. The switching circuit is configured in a first mode to disable the PA and to connect the input of the LNA to the antenna for receiving signals from the antenna. The switching circuit is configured in a second mode to disconnect the input of the LNA from the antenna and to enable the PA for transmitting signals to the antenna.
    Type: Grant
    Filed: January 5, 2017
    Date of Patent: October 30, 2018
    Assignee: Coolstar Technology, Inc.
    Inventor: Shuming Xu
  • Patent number: 9704855
    Abstract: A method of integrating at least one passive component and at least one active power device on a same substrate includes: forming a substrate having a first resistivity value associated therewith; forming a low-resistivity region having a second resistivity value associated therewith in the substrate, the second resistivity value being lower than the first resistivity value; forming the at least one active power device in the low-resistivity region; forming an insulating layer over at least a portion of the at least one active power device; and forming the at least one passive component on an upper surface of the insulating layer above the substrate having the first resistivity value, the at least one passive component being disposed laterally relative to the at least one active power device and electrically connected with the at least one active power device.
    Type: Grant
    Filed: November 23, 2015
    Date of Patent: July 11, 2017
    Assignee: CoolStar Technology, Inc.
    Inventors: Shuming Xu, Wenhua Dai
  • Patent number: 9628118
    Abstract: An RF PA is designed to operate efficiently for average powers when biased at the system supply voltage, and uses an envelope tracking power supply to boost the bias voltage to maintain good efficiency at higher powers. As a result, for a majority of the time when transmitting average power signals, the RF PA bias voltage is the system-wide supply voltage (e.g. 3.4V in cell phones), which eliminates the need for stepping down voltages. The bias voltage is boosted during the less frequent times when higher power is needed. As a result, only a boost type of DC voltage converter is needed. The efficiency of the RF PA is therefore increased because voltage conversion is required less frequently and only when higher power RF signals are transmitted.
    Type: Grant
    Filed: July 31, 2015
    Date of Patent: April 18, 2017
    Assignee: Coolstar Technology, Inc.
    Inventors: Shuming Xu, Wenhua Dai
  • Patent number: 9502557
    Abstract: An LDMOSFET is designed with dual modes. At the high voltage mode, it supports a high breakdown voltage and is biased at a high voltage to get the benefits of high output power, higher output impedance and lower matching loss. At the low voltage mode, it exhibits a reduced knee voltage so that some extra voltage and power can be gained although it is biased at lower voltage. The efficiency is therefore improved as well.
    Type: Grant
    Filed: September 8, 2015
    Date of Patent: November 22, 2016
    Assignee: Coolstar Technology, Inc.
    Inventors: Shuming Xu, Wenhua Dai