Hyung Seok Kim

A 32 nm SoC With Dual Core ATOM Processor and RF WiFi Transceiver

An × 86 standard operating system compliant System-on-Chip (SoC) with a dual core ATOM processor and a custom interconnect fabric to enable modular design is presented. The 32 nm SoC includes integrated PCI-e Gen 2, DDR3, legacy I/O, voltage regulators, clock generation, power management, memory controller and RF portion of a WiFi transceiver in a 32 nm high-k/metal-gate RF CMOS process with high resistivity substrate. The integrated RF transceiver for 2.4 GHz 802.11g operation achieves a receive sensitivity of -74 dBm, -8 dBm IIP3 and a transmit output power of 20.3 dBm (-25 dB EVM) at 14% TX RF efficiency.

A Digital Fractional-N PLL With a PVT and Mismatch Insensitive TDC Utilizing Equivalent Time Sampling Technique

A 6-bit time-to-digital converter that achieves mismatch free operation by using a single delay cell and sampling flip-flop is presented. The proposed TDC was integrated in a digital fractional-N PLL fabricated in a 32-nm digital SoC CMOS process for WiFi/WiMax radios. The TDC consumes 3 mW from a 1.05-V supply and occupies an area of 0.004 mm2. A digital frequency-locked loop is used to track and correct for PVT variations in the TDC and no additional linearization or mismatch calibrations are required. The DPLL uses a 20-bit high dynamic range DAC to drive a VCO in order to effectively realize a DCO with 100-Hz frequency resolution. The 2.5-GHz WiFi band LO output is generated from a 40-MHz reference with an integrated phase noise of - 35 dBc (10 kHz to 10 MHz) while consuming 21 mW . The worst case spur in the LO output is below - 50 dBc without requiring TDC mismatch and linearity calibration.

A reconfigurable distributed all-digital clock generator core with SSC and skew correction in 22nm high-k tri-gate LP CMOS

Diverse spread spectrum clocking (SSC) generation requirements necessitate multiple reference clocks, extra pins, and off-chip components. With analog integer-n PLL-based clock generators, it is difficult to meet all these needs with a common reference clock. One disadvantage is that the frequency resolution in an integer-n PLL is limited by the reference frequency. A lower reference frequency limits the bandwidth and lock time, amplifies jitter from the reference, and increases the loop filter area. Additionally, analog PLLs suffer from unpredictable loop dynamics and clock skews with PVT, mismatch, and transistor leakage, further exacerbated by process scaling. Turning off and waking up an analog PLL requires charging or discharging loop filter capacitors which is inherently slow. This paper presents an all-digital clock generation architecture which (1) provides fractional-n capability in the digital domain; (2) implements SSC within the PLL loop; (3) performs digital clock deskew; and (4) provides dynamic loop bandwidth adjustment to shorten lock time.

32nm x86 OS-compliant PC on-chip with dual-core Atom® processor and RF WiFi transceiver

Embedded PC applications are growing, driven by their cost, performance and software compatibility. The SoC described in this work is a unique device designed for rapid integration and customization for specific market segments. A rich multi-source IP eco-system consisting of standardized interfaces, modular and configurable building blocks, enables automation and fast execution to deliver a broad range of targeted solutions. Integrating high-performance digital circuits with analog and RF circuits on a leading edge process enables our SoC architecture to increase the level of integration, performance and reduce the cost of the platform. WiFi has remained an external PC component due to the challenges of managing system noise from the digital circuits. This paper presents an integrated standard x86 OS compliant, dual-core ATOM® processor-based SoC, including the RF WiFi to drive down platform cost. Key enabling features are: (a) a 32nm RF process with HV transistors and RF passives; (b) an on-chip interconnect fabric for modularity; (c) a clock generator with SSC to reduce substrate noise injection and EMI; (d) voltage regulators for power management and rail reduction; (e) an 802.11b/g RF WiFi transceiver with integrated LNA, PA, T/R switch and BIST/calibration engine.

A 2.4GHz WLAN transceiver with fully-integrated highly-linear 1.8V 28.4dBm PA, 34dBm T/R switch, 240MS/s DAC, 320MS/s ADC, and DPLL in 32nm SoC CMOS

A 2.4GHz WLAN transceiver is presented with a fully-integrated highly-linear 28.4dBm PA, 34dBm T/R switch, 240MS/s DAC and 320MS/s ADC (high OSR for relaxed filtering), DPLL and fractional LOG, in 32nm CMOS. For 802.11g 54Mbps, without linearization the TX delivers 19.8dBm at 12.5% efficiency (PA 21.6dBm/19.7% PAE) for -25dB EVM and mask-compliant 22.8dBm/18.5%, while the RX achieves 4.8dB NF, -69dBm sensitivity, and -8dBm IIP3.

13.6 A 2.4GHz WLAN digital polar transmitter with synthesized digital-to-time converter in 14nm trigate/FinFET technology for IoT and wearable applications

To benefit from Moores law and minimize form-factor and active power consumption, digital-rich SoCs should be integrated in the most advanced technology node. If the transceiver is integrated in a different technology node, multi-chip solutions are required, increasing system cost and form-factor. Traditional radio architectures require extensive use of high-quality passives, which might use large silicon area or not be available due to process limitations. Fast time to market also demands quicker design cycles, where extensive use of standard digital cells and even automated place-and-route tools for layout is preferred [1]. The proposed transmitter leverages a polar architecture with synthesized digital-to-time converter (DTC) wideband phase modulator, an all-digital PLL and a digital PA with matching network implemented on a flip-chip package to enable single-chip integration in 14nm trigate/finFET technology for IoT and wearable SoCs.

A 32nm, 0.65–10GHz, 0.9/0.3 ps/σ TX/RX jitter single inductor digital fractional-n clock generator for reconfigurable serial I/O

In CPU, SOC, GPU, and PC-on-chip, I/O power consumption can be significant. To improve power efficiency, I/O bundles in group of 4, 8, or 16b, should scale their data rate according to the application requirements. However, clocking architecture imposes significant challenges to support different data rate simultaneously. In high bandwidth I/O, LC oscillators are preferred for low jitter, but the limited frequency range confines the data rate tuning. Multiple LC-PLLs are costly in area and power, and sometimes infeasible due to heavily congested I/O area. Worse still, couplings between inductors could lead to PLL pulling closing the sampling eye. In this paper, a reconfigurable 0.65–10GHz digital fractional-n clock generator using a single LC PLL, calibrated 0.75/1.25/1.75 digital fractional post dividers for serial I/O is presented. The architecture enables I/O driven by the same PLL to operate at different data rate, thereby reducing power. In addition, multiple LC-PLLs are replaced by one saving area, power, and coupling between LC oscillators. The PLL incorporates a staggered varactor, wide-tuning VCO, and a hysteretic redundant frequency acquisition for improved temperature stability. The prototype in a 32nm high-k metal gate process has a measured TX/RX jitter of 0.9/0.3 ps/σ and dissipates 36.2mW from 1.05V supply.

A digital fractional-N PLL with a 3mW 0.004mm 2 6-bit PVT and mismatch insensitive TDC

In this paper, a 3mW 0.004mm2 6-bit time-to-digital converter (TDC) is presented. By re-using a single delay cell and sampling flip-flop (FF), mismatch free operation is achieved. PVT variations are tracked and corrected by a digital frequency lock loop (DFLL). The proposed TDC is demonstrated in a digital fractional-N PLL for WiFi/4G radios. A 20-bit high dynamic range (DR) digital-to-analog converter (DAC) drives the VCO to achieve 100Hz resolution. The PLL is fabricated in 32nm digital SoC CMOS with a flip-chip BGA package. The PLL produces a 2.5GHz band LO output with -35dBc integrated phase noise (10kHz to 10MHz) and the worst case spur less than -50dBc while consuming 21mW.