Abstract: Embodiments of the present invention provide an oscillator circuit having a steady output frequency that is independent of the supplied voltage. This oscillator includes a Schmitt trigger circuit which may be implemented within an integrated circuit of a wireless terminal or other like portable electronic device. The Schmitt trigger circuit receives a threshold voltage input and a second voltage input. The Schmitt trigger circuit generates an output voltage equal to either a first output voltage or a second output voltage based on the results of comparing the threshold voltage input to the second voltage input. An RC network may be coupled to the output of the Schmitt trigger circuit and is operable to supply the second voltage input to the Schmitt trigger circuit.

Abstract: A transceiver is provided for wireless communication. The transceiver can include a bias source, a transformer including a primary side and a secondary side, and a switching device. During a receive mode, the primary side of the transformer is configured to receive a first signal from a first port. During a transmission mode, the primary side is configured to transmit a second signal from a second port. The switching device is configured to couple the first port to the bias source during transmission of the second signal and to couple the second port to the bias source during receipt of the first signal. The bias source can be, for example, ground.

Abstract: A transceiver is provided for wireless communication. The transceiver can include a bias source, a transformer including a primary side and a secondary side, and a switching device. During a receive mode, the primary side of the transformer is configured to receive a first signal from a first port. During a transmission mode, the primary side is configured to transmit a second signal from a second port. The switching device is configured to couple the first port to the bias source during transmission of the second signal and to couple the second port to the bias source during receipt of the first signal. The bias source can be, for example, ground.

Abstract: A receiver within a wireless device is able to couple to different antennas with different impedances. The wireless device includes a first antenna pin for coupling to a first antenna with a first impedance, a second antenna pin for coupling to a second antenna with a second impedance and a switch for selecting at least one of the first antenna and the second antenna to couple to the receiver.

Abstract: A chip comprises and operational section and an input/output section. The operational section includes a controller. The input/output (I/O) section is coupled to the operational section. The I/O section comprises a transformer and a switching device. The transformer includes a primary side connected to first and second I/O ports and a secondary side connected to the operational section. The switching device is coupled to the controller and between the first and second I/O ports and a bias port, such that, under control of the controller, the switching device connects one of the first and second I/O ports to the bias port.

Abstract: An ESD protection circuit for a switch coupled to high-speed signaling pins of an integrated circuit includes a first string of clamping elements and a second string of clamping elements. The first string of clamping elements has a collective capacitance less than the capacitance of a single clamping element. The first string of clamping elements is operably coupled to the drain and source of the transistor and conducts when a first polarity ESD voltage is applied to the high-speed pins. The second string of clamping elements has a collective capacitance less than the capacitance of one clamping element. The second string of clamping elements is operably coupled to the drain and source of the transistor and conducts when a second polarity ESD voltage is applied to the high speed signaling pins.

Abstract: An ESD protection circuit for a transistor having a drain and source coupled to high-speed signaling pins of an integrated circuit includes a first string of clamping elements and a second string of clamping elements. The first string of clamping elements has a collective capacitance less than the capacitance of a single clamping element. The first string of clamping elements is operably coupled to the drain and source of the transistor and conducts when a first polarity ESD voltage is applied to the high-speed pins. The second string of clamping elements has a collective capacitance less than the capacitance of one clamping element. The second string of clamping elements is operably coupled to the drain and source of the transistor and conducts when a second polarity ESD voltage is applied to the high speed signaling pins.

Abstract: Embodiments of the present invention provide an oscillator circuit having a steady output frequency that is independent of the supplied voltage. This oscillator includes a Schmitt trigger circuit which may be implemented within an integrated circuit of a wireless terminal or other like portable electronic device. The Schmitt trigger circuit receives a threshold voltage input and a second voltage input. The Schmitt trigger circuit generates an output voltage equal to either a first output voltage or a second output voltage based on the results of comparing the threshold voltage input to the second voltage input. An RC network may be coupled to the output of the Schmitt trigger circuit and is operable to supply the second voltage input to the Schmitt trigger circuit.

Abstract: Embodiments of the present invention provide an oscillator circuit having a steady output frequency that is independent of the supplied voltage. This oscillator includes a Schmitt trigger circuit which may be implemented within an integrated circuit of a wireless terminal or other like portable electronic device. The Schmitt trigger circuit receives a threshold voltage input and a second voltage input. The Schmitt trigger circuit generates an output voltage equal to either a first output voltage or a second output voltage based on the results of comparing the threshold voltage input to the second voltage input. An RC network may be coupled to the output of the Schmitt trigger circuit and is operable to supply the second voltage input to the Schmitt trigger circuit.

Abstract: An apparatus and method for allowing two different signal paths to be coupled to a multi-tap transformer balun. The multi-tap transformer has a first port, which is coupled to a single antenna, and two or more differential secondary ports. Each port has one or more taps, which are optimized separately for each of the signal paths, allowing each of the two or more signal paths to operate in different frequency bands. Use of the method of the invention can decrease the number of external components and integrated circuit package pins, and reduce the area required for each signal path on an integrated circuit die, a printed circuit board, or the like.

Abstract: A chip comprises and operational section and an input/output section. The operational section includes a controller. The input/output (I/O) section is coupled to the operational section. The I/O section comprises a transformer and a switching device. The transformer includes a primary side connected to first and second I/O ports and a secondary side connected to the operational section. The switching device is coupled to the controller and between the first and second I/O ports and a bias port, such that, under control of the controller, the switching device connects one of the first and second I/O ports to the bias port.

Abstract: A complex filter such as the channel select filter in a radio transceiver is implemented using a transconductance/C topology to benefit from the ability to tune such filters and thereby stabilize the output transfer function of the filter over variations in temperature, power supply voltage and process. The topology is based on an active R/C biquadratic topology to achieve the additional benefit of independently controlled stages. The problem created by the R in the output impedance is can be overcome by separately tuning the R value along with the transconductance/C ratio, by implementing the R as a transconductance amplifier having common mode feedback, or by implementing the transconductance amplifiers of the topology using Nauta transconductors, and unbalancing the common mode circuit of the Nauta transconductor to achieve a differential resistance that can be used to implement the R in the output impedance.

Abstract: An on chip diversity antenna switch includes a first switch, a second switch, a third switch, and a fourth switch. The first switch is operably coupled to a pin associated with a first antenna, to a transmit path and to receive a transmit receive (T/R) control signal. The second switch is operably coupled to the pin associated with the first antenna, to a receive path, and to receive the T/R control signal. The third switch is operably coupled to a pin associated with a second antenna, the transmit path, and to receive the T/R control signal. The fourth switch is operably coupled to the pin associated with the second antenna, to the receive path, and to receive the T/R control signal. Based on the T/R control signal, the first or second antenna is coupled to the transmit or receive path via a single switch.

Abstract: A complex filter such as the channel select filter in a radio transceiver is implemented using a transconductance/C topology to benefit from the ability to tune such filters and thereby stabilize the output transfer function of the filter over variations in temperature, power supply voltage and process. The topology is based on an active R/C biquadratic topology to achieve the additional benefit of independently controlled stages. The problem created by the R in the output impedance is can be overcome by separately tuning the R value along with the transconductance/C ratio, by implementing the R as a transconductance amplifier having common mode feedback, or by implementing the transconductance amplifiers of the topology using Nauta transconductors, and unbalancing the common mode circuit of the Nauta transconductor to achieve a differential resistance that can be used to implement the R in the output impedance.

Abstract: An on chip diversity antenna switch includes a first switch, a second switch, a third switch, and a fourth switch. The first switch is operably coupled to a pin associated with a first antenna, to a transmit path and to receive a transmit receive (T/R) control signal. The second switch is operably coupled to the pin associated with the first antenna, to a receive path, and to receive the T/R control signal. The third switch is operably coupled to a pin associated with a second antenna, the transmit path, and to receive the T/R control signal. The fourth switch is operably coupled to the pin associated with the second antenna, to the receive path, and to receive the T/R control signal. Based on the T/R control signal, the first or second antenna is coupled to the transmit or receive path via a single switch.

Abstract: An ESD protection circuit for a transistor having a drain and source coupled to high-speed signaling pins of an integrated circuit includes a first string of clamping elements and a second string of clamping elements. The first string of clamping elements has a collective capacitance less than the capacitance of a single clamping element. The first string of clamping elements is operably coupled to the drain and source of the transistor and conducts when a first polarity ESD voltage is applied to the high-speed pins. The second string of clamping elements has a collective capacitance less than the capacitance of one clamping element. The second string of clamping elements is operably coupled to the drain and source of the transistor and conducts when a second polarity ESD voltage is applied to the high speed signaling pins.

Abstract: A complex filter such as the channel select filter in a radio transceiver is implemented using a transconductance/C topology to benefit from the ability to tune such filters and thereby stabilize the output transfer function of the filter over variations in temperature, power supply voltage and process. The topology is based on an active R/C biquadratic topology to achieve the additional benefit of independently controlled stages. The problem created by the R in the output impedance is can be overcome by separately tuning the R value along with the transconductance/C ratio, by implementing the R as a transconductance amplifier having common mode feedback, or by implementing the transconductance amplifiers of the topology using Nauta transconductors, and unbalancing the common mode circuit of the Nauta transconductor to achieve a differential resistance that can be used to implement the R in the output impedance.