Abstract: A new trans-impedance amplifier (TIA) with low noise is provided. The TIA may include an input stage and an output driving stage. The input stage may include a pair of input PMOS transistors, a pair of input NMOS transistors, and a pair of differential voltage input nodes. The output driving stage may include a pair of output circuits, each may include a first pair of PMOS and NMOS transistors electrically connected in parallel, a second pair of PMOS and NMOS transistors electrically connected in series, and a pair of capacitors electrically connected in series, which are electrically connected in parallel. The structure can lead to a reduced noise level of the TIA.

Abstract: A trans-impedance amplifier (TIA) may include an input stage and an output driving stage. The input stage may include a pair of input PMOS transistors, a pair of input NMOS transistors, and a pair of differential voltage input nodes. The output driving stage may include a pair of output circuits, each may include a first pair of PMOS and NMOS transistors electrically connected in parallel, a second pair of PMOS and NMOS transistors electrically connected in series, a pair of capacitors electrically connected in series, a differential output node, a third PMOS transistor, and a fourth pair of NMOS transistors cross-coupled between the pair of output circuits of the output driving stage. The structure can lead to a reduced noise level and a reduced peak transient current level of the TIA.

Abstract: A frequency synthesizer, comprises a phase frequency detector to receive a frequency signal and a reference clock, and to output a phase difference according to a phase difference and a frequency difference between the frequency signal and the reference clock; a charge pump to generate a current according to the phase difference; a loop filter to generate a first voltage signal based on the current; a N-path filter each comprising a switch, a path filter and to generate N paths of filtered voltages based on the first voltage; a voltage control oscillator to generate a second voltage signal based on a sum of the N paths of filtered voltages; a frequency divider to generate the frequency signal based on the second voltage signal and a variable frequency dividing ratio; and a Sigma-Delta Modulator to generate the variable frequency dividing ratio based on a digital representation of a frequency fractional value and the reference clock.

Abstract: A power management system comprises an input power detector configured to generate a first enablement signal by detecting whether a first voltage is supplied; a first output stage connected to the input power detector and configured to receive and regulate the first voltage upon receiving the first enablement signal; an error operational amplifier is connected to the first output stage, a first input port of the error operational amplifier is configured to receive a first reference voltage, a second input port of the error operational amplifier is connected to a connection point of a first resistor and a second resistor, the first resistor is connected to the first output stage, the second resistor is connected to ground, and a system output port is located at the connection of the output port of the first output stage and the first resistor, to drive a load.

Abstract: A wireless communication method without pairing IDs in advance, comprises: transmitting, at a first power, a first ID within a first pipe; searching for a second ID on at least one frequency point, wherein the second ID matches the first ID; if the second ID is not found within the first pipe, respectively transmitting, at least at a second power and a third power, at least two matching-code requests within a public pipe on public frequency points; receiving ACKs responding to each of the matching-code requests from different devices; summing numbers of the received ACKs from each device; comparing the summed numbers of the received ACKs from the different devices to get a maximum number; switching from a public pipe to a third pipe of a device that sent the maximum number of ACKs; transmitting a matching-code package to the device that sent the maximum number of ACKs.

Abstract: A wireless communication method without pairing IDs in advance, comprises: transmitting, at a first power, a first ID within a first pipe; searching for a second ID on at least one frequency point, wherein the second ID matches the first ID; if the second ID is not found within the first pipe, respectively transmitting, at least at a second power and a third power, at least two matching-code requests within a public pipe on public frequency points; receiving ACKs responding to each of the matching-code requests from different devices; summing numbers of the received ACKs from each device; comparing the summed numbers of the received ACKs from the different devices to get a maximum number; switching from a public pipe to a third pipe of a device that sent the maximum number of ACKs; transmitting a matching-code package to the device that sent the maximum number of ACKs.

Abstract: An amplifier comprises a biasing unit, an amplifying unit and a Schmitt trigger. The biasing unit is configured to generate a bias current which is independent of the power supply, so as to increase power supply rejection ratio. The amplifying unit is connected to the biasing unit and configured to receive an input voltage and generate an amplified voltage based on the biasing current. The Schmitt trigger is connected to the amplifier and configured to generate and output a modified voltage.

Abstract: An amplifier comprises a biasing unit, an amplifying unit and a Schmitt trigger. The biasing unit is configured to generate a bias current which is independent of the power supply, so as to increase power supply rejection ratio. The amplifying unit is connected to the biasing unit and configured to receive an input voltage and generate an amplified voltage based on the biasing current. The Schmitt trigger is connected to the amplifier and configured to generate and output a modified voltage.

Abstract: A first circuit is configured to communicatively couple to a second circuit including an analog circuit and a digital circuit. The first circuit comprises a lock unit and a sleep unit. The lock unit is configured to receive a lock enable signal and to lock a configuration signal of the digital circuit in response to the lock enable signal. The sleep unit is configured to receive a sleep triggering signal indicating to switch into sleep mode and to generate an off signal to switch off the digital circuit in response to the sleep triggering signal, while the analog circuit remains on.

Abstract: A circuit comprises an oscillator, a frequency divider and a comparator. The oscillator generates an oscillating signal (Fvco). The frequency divider is communicatively coupled to the oscillator, divides a frequency of the oscillating signal by a denominator and generates a divided signal. The comparator is communicatively coupled to the oscillator and the frequency divider, and is configured to obtain a first count of the divided signal (Fvco/N) within a predetermined time and a second count of a reference signal within the predetermined time; compare the first count with the second count, and generate a comparison result according to the first count and the second count. The oscillator is further configured to adjust the frequency of the oscillating signal according to the comparison result.

Abstract: A circuit comprises an oscillator, a frequency divider and a comparator. The oscillator generates an oscillating signal (Fvco). The frequency divider is communicatively coupled to the oscillator, divides a frequency of the oscillating signal by a denominator and generates a divided signal. The comparator is communicatively coupled to the oscillator and the frequency divider, and is configured to obtain a first count of the divided signal (Fvco/N) within a predetermined time and a second count of a reference signal within the predetermined time; compare the first count with the second count, and generate a comparison result according to the first count and the second count. The oscillator is further configured to adjust the frequency of the oscillating signal according to the comparison result.

Abstract: A first circuit is configured to communicatively couple to a second circuit including an analog circuit and a digital circuit. The first circuit comprises a lock unit and a sleep unit. The lock unit is configured to receive a lock enable signal and to lock a configuration signal of the digital circuit in response to the lock enable signal. The sleep unit is configured to receive a sleep triggering signal indicating to switch into sleep mode and to generate an off signal to switch off the digital circuit in response to the sleep triggering signal, while the analog circuit remains on.

Abstract: A PLL circuit comprises a phase frequency detector (PFD), a charge pump (CP), a low pass filter (LPF), a voltage controlled oscillator (VCO), a frequency divider (FD) and a reset module. The PFD receives a first and a second input signals, and outputs a first and a second adjustment parameters according to phase and frequency difference between the first and the second input signal. The CP is coupled to the PFD, generates a current according to the first and the second adjustment parameters. The LPF is coupled to the CP, and generates a voltage according to the current. The VCO is coupled to the LPF, and generates an oscillation frequency according to the voltage. The FD receives and divides the oscillation frequency, and generates the second input signal. The reset module generates a reset signal to feed to the FD, wherein the reset module receives the first signal.

Abstract: A GFSK modulator comprises: a first compensation module, configured to receive a GFSK pulse signal, apply a first amplitude compensation and a first delay compensation to the GFSK pulse signal, so as to generate a first compensated control signal; a second compensation module, configured to receive the GFSK pulse signal, apply a second amplitude compensation and a second delay compensation to the GFSK pulse signal, so as to generate a second compensated control signal; a closed-loop PLL module including a closed-loop PLL, configured to receive and use the first and the second compensated control signals to generate a modulated signal.

Abstract: A GFSK modulator comprises: a first compensation module, configured to receive a GFSK pulse signal, apply a first amplitude compensation and a first delay compensation to the GFSK pulse signal, so as to generate a first compensated control signal; a second compensation module, configured to receive the GFSK pulse signal, apply a second amplitude compensation and a second delay compensation to the GFSK pulse signal, so as to generate a second compensated control signal; a closed-loop PLL module including a closed-loop PLL, configured to receive and use the first and the second compensated control signals to generate a modulated signal.

Abstract: A method and apparatus for demodulating an input signal, for example, in a communications system, is disclosed. The apparatus includes a signal preconditioner and a demodulator. The signal preconditioner may include a low-pass filter and a hysteretic comparator that are configured to precondition a preconditioner input signal to provide a preconditioner output signal. The modulator may be configured to demodulate the preconditioner output signal.

Abstract: This disclosure discloses methods and apparatus for calibrating received signal strength indicators.

Abstract: This disclosure discloses methods and apparatus for calibrating received signal strength indicators.

Abstract: This disclosure discloses methods and apparatus for calibrating received signal strength indicators.

Abstract: This disclosure discloses methods and apparatus for calibrating received signal strength indicators.