Mediatek Singapore Pte. Ltd.

Chin-Heng Leow

Tieng Ying Choke

Osama K A Shana'a

Yuan Sun

Eng-Chuan Low

Wee-Liang Lien

Chee Hong Yong

Xu-Dong Jiang

Chee Guan Ho

Geok Teng Ong

Tze Yee Sin

A push-start crystal oscillator (XO), an associated electronic device and a push-start method for performing a start-up procedure of an XO are provided. The push-start XO includes an inverting amplifier and a push-start logic control circuit, wherein the inverting amplifier is coupled to a crystal load. The inverting amplifier generates a first XO signal and a second XO signal. The push-start logic control circuit receives a feedback clock from a phase locked loop (PLL), and generates a phase control clock according to the feedback clock, wherein a push phase and a settle phase are specified by the phase control clock. During the settle phase, the PLL calibrates a frequency of the feedback clock according to the second XO signal. During the push phase, the feedback clock is transmitted to the inverting amplifier in order to increase the amplitude of the first XO signal.

Push-start crystal oscillator, associated electronic device and push-start method for performing start-up procedure of crystal oscillator

A parameter monitor and method for monitoring a parameter of a passive component on an integrated circuit. The parameter monitor includes an oscillator circuit. The parameter monitor also includes circuitry configured to measure a first time period of an oscillation of the oscillator circuit with a passive component to produce a first digital count value, to measure second time period of an oscillation of the oscillator circuit without the passive component to produce a second digital count value, and generate a code indicative of a value of or a variation in the value of the passive component using the first and second digital count values.

Passive monitor for integrated circuit components

Circuits and methods for active load modulation is described. These circuits and methods may be employed in connection with near field communication (NFC) systems, for example in the proximity inductive coupling card (PICC). The methods described herein may be used to synchronize the operations of the system to the carrier clock provided by a reader with typical operation frequency of 13.56 MHz&#xb1;7 KHz. The synchronization may be performed by locking an internal clock to the carrier clock when the transmission of data is disabled, by locking the internal clock to a local clock when data transmission is enabled, and by compensating the phase or frequency of the active load modulation clock to track the carrier clock.

High-speed circuits for active load modulation and related methods

A proximity sensing method employed by a wireless communications device includes the steps of: performing a first predetermined operation to detect a presence of at least a transponder in the proximity of the wireless communications device; when the presence of a transponder in the proximity of the wireless communications device is not detected by the first predetermined operation, performing a second predetermined operation to obtain a first characteristic value and after a period of time, performing the second predetermined operation to obtain a second characteristic value sequentially; checking if the first characteristic value and the second characteristic value satisfy a predetermined criteria; and when the predetermined criterion is satisfied, performing the first predetermined operation again to check the presence of the transponder in the proximity of the wireless communications device.

Proximity sensing method using loopback mechanism and wireless communications device thereof

A method for controlling a modulation index of a near field communication (NFC) device includes: in a calibration mode of the NFC device, coupling a receiver of the NFC device to a transmitter of the NFC device to form a probing path between the receiver and the transmitter; and in the calibration mode of the NFC device, adjusting at least one portion of a plurality of modulation parameters corresponding to the modulation index according to probed results of outputs of the transmitter, in order to calibrate the modulation index, for use of transmitting through the transmitter in a normal mode of the NFC device. An associated apparatus is also provided.

Method for controlling a modulation index of a near field communication device with aid of dynamic calibration, and associated apparatus

A method for controlling a modulation index of a near field communication (NFC) device includes: in a calibration mode of the NFC device, temporarily coupling a receiver of the NFC device to a transmitter of the NFC device to form a probing path between the receiver and the transmitter; and in the calibration mode of the NFC device, dynamically adjusting at least one portion of a plurality of modulation parameters corresponding to the modulation index according to probed results of outputs of the transmitter, in order to calibrate the modulation index, for use of transmitting through the transmitter in a normal mode of the NFC device. An associated apparatus is also provided.

A radio-frequency (RF) front-end circuit includes a tunable filter, a negative transconductance circuit coupled with the tunable filter to produce a tuning oscillation signal, and a counter arranged to determine a frequency of the tuning oscillation signal. The RF front-end circuit also includes a control circuit arranged to shift the frequency of the tuning oscillation signal by adjusting the tunable filter until the frequency of the tuning oscillation signal falls within an acceptable frequency range corresponding to a desired channel frequency band.

Growing community of inventors

Singapore, Singapore

Chin-Heng Leow