Hong Kong Applied Science and Technology Research Institute Company, Limited

High Tech Technology Limited

Tin Ho (Andy) Wu

Kwai Chi Chan

Ho Ming (Karen) Wan

Chik Wai (David) Ng

Wai Kit (Victor) So

Kam Chuen Wan

Yat To (William) Wong

Hok Mo Yau

Ka Lok (Roy) Ng

Yuanzhe (Kevin) Xu

Ki Hin (Gary) Choi

Kwun Yuan (Godwin) Ho

An Integrated Circuit (IC) package has a ferrite-dielectric shield between a planar inductor coil and a semiconductor chip. The shield blocks Electro-Magnetic Interference (EMI) generated by currents in the inductor coil from reaching the semiconductor chip. The shield has a ferrite layer surrounded by upper and lower dielectric laminate layers to prevent electrical shorts. The center end of the inductor coil connects to the semiconductor chip through a center post that fits through an opening in the shield that is over the air core center of the inductor coil. The center post can connect to a die attach pad that the semiconductor chip is mounted to. Bonding wires connect pads on the semiconductor chip to lead-frame pads on lead-frame risers that end at external package connectors. The outer end of the inductor coil connects to lead-frame outer risers also having external package connectors such as pins or bonding balls.

Ferrite electro-magnetic interference (EMI) shield between an integrated-circuit (IC) chip and an air-core inductor all inside a hybrid lead-frame package

A modulator spreads the spectrum of a generated clock to reduce Electro-Magnetic Interference (EMI). A capacitor is charged by a variable current to generate a ramp voltage that is compared to a reference to end a clock cycle and discharge the capacitor. An up-down counter drives a Digital-to-Analog Converter (DAC) that controls the variable charging current to provide triangle modulation. A smaller offset current is added or subtracted for cubic modulation when the up-down counter reaches its minimum count. A frequency divider that clocks the up-down counter also clocks a Linear-Feedback Shift-Register (LFSR) to that controls pseudo-random current sources that further modulate variable current and frequency. The LFSR is clocked with the up-down counter to modulate each frequency step, or only at the minimum count to randomly modulate at the minimum frequency. Binary-weighted bits from the up-down counter to the DAC are swapped to modulate the frequency step size.

Digital frequency dithering for switched-mode power supplies (SMPS) using triangular, asymmetric cubic, or random cubic spread spectrum oscillators

A correcting asynchronous Successive-Approximation Register (SAR) analog-to-digital converter (ADC) detects and corrects metastability errors. An analog signal is synchronously sampled by a system clock, but data bits are converted asynchronously. A valid detector compares true and complement outputs of a comparator that compares the sampled voltage to a DAC voltage generated from digital test value from the SAR. Once the true and complement outputs diverge past logic thresholds, the valid detector activates a VALID signal indicating that comparison is completed. The compare result is then latched in as a data bit and the SAR advances to the next test value. Once all bits have been converted, an End-of-Conversion (EOC) is signaled. If the EOC does not occur by the end of the system clock, a metastability error is detected. The current bit that never finished comparison is forced high and all other unconverted bits are forced low.

Asynchronous successive-approximation-register analog-to-digital converter (SAR ADC) in synchronized system

A Programmable-Gain Amplifier (PGA) has a digital value that programmably adjusts the gain of the analog amplifier. A variable capacitor has several switched sub-capacitors that are enabled by the digital value. Enabled sub-capacitors are switched between a sampled input and a virtual ground on one terminal, and connect to a summing node on the other terminal. The summing node connects to the inverting input of an op amp either through a switch or through a double-sampling capacitor that stores an offset. A feedback capacitor is in parallel with a sampling capacitor during a second clock phase when direct-charge transfer occurs, reducing power consumption of the amplifier. The feedback capacitor samples the sampled input during the first clock phase. The PGA gain is proportional to the sum of capacitances of enabled sub-capacitors. The gain can be adjusted for sensor inputs to an Analog Front-End (AFE), such as for an electro-cardiogram (ECG).

Digitally-programmable gain amplifier with direct-charge transfer and offset cancellation

A Successive-Approximation Register Analog-to-Digital Converter (SAR-ADC) predicts compensation values for use in a future cycle. A compensation value is applied to capacitors in a calibration Y-side capacitor array to compensate for capacitance errors in a binary-weighted X-side capacitor array. Two compute engines pre-calculate predicted-0 and predicted-1 compensation values for a next bit to be converted. At the end of the current cycle when the comparator determines the current bit, the comparator also controls a mux to select one of the two predicted compensation values. Thus the compensation value is available at the beginning of the next bit's cycle, eliminating a long calculation delay. The compensation value for the first bit to be converted, such as the MSB, is calculated during calibration. Compensation values for other bits are data-dependent. Calibration values are accumulated during calibration to generate the first conversion compensation value for the first bit to be converted.

Parallel pipelined calculation of two calibration values during the prior conversion cycle in a successive-approximation-register analog-to-digital converter (SAR-ADC)

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Hong Kong, China

Tin Ho (Andy) Wu