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The present paper addresses an improved low-power high-speed buffer amplifier topology for large-size liquid crystal display applications. The proposed buffer achieves high-speed driving performance while drawing a low quiescent current during static operation. The circuit offers enhanced slewing capabilities with a limited power consumption by exploiting a slew detector which monitors the output voltage of the input differential amplifier and outputs an additional current signal providing slew-rate enhancement at the output stage. Post-layout simulations show that the proposed buffer can drive a 1 nF column line load with 8.5 V/μs slew-rate and 0.8 μs settling time, while drawing only 8 μA static current from a 3 V power supply.

This work presents a high-slew rate rail-to-rail buffer amplifier, which can be used for flat panel displays. The proposed buffer amplifier is composed of two transconductance amplifiers, two current comparators and a push-pull output stage. Phase compensation technique is also used to improve the phase margin value of the proposed buffer amplifier for different load capacitances. Post-layout simulations of the proposed buffer amplifier are performed using 0.35 μm AMS CMOS process parameters and 3.3 V power supply. The circuit is tested under a 600 pF capacitive load. An average settling time of 0.85 μs under a full voltage swing is obtained, while only 3 μA quiescent current is drawn from the power supply. Monte Carlo analysis is also added to show the process variation effects on the circuit.

In this paper, a single-stage multi-path operational transconductance amplifier (OTA) with fast-settling response for high performance applications is designed. The produced amplifier uses current-shunt technique, double recycling structure, cross-coupled positive feedback configuration and all idle devices in the signal path to enhance transconductance of the conventional folded cascode (FC) amplifier. These transconductance boosting techniques lead to higher DC gain, gain bandwidth (GBW), slew rate and lower settling time compared to the previous FC structures while phase margin is degraded. Simulation results are presented using 90 nm CMOS technology which show 1,800% increment in GBW and a 33.2 dB DC gain improvement in the approximately same power consumption compared to the conventional FC amplifier.

Frequency-modulated continuous-wave (FMCW) signals-based radar systems can outrun the optical and ultrasound sensors in dark and severe weather conditions. FMCW radar systems require a fast settling frequency synthesizer to reduce the chirp signal’s inactive and modulation times. This work proposes a new C-B and FMCW Transmitter based on Fast Settling Fractional-N DPLL (FS-FNDPLL) and ring-based pulse injection locking oscillator (R-PILO). The proposed FS-FNDPLL generates an ultra-fast low-noise smooth narrowband chirp by introducing an automatic controller-based TDC switching (AC-TDCSw) scheme in the forward loop of FNDPLL. Also, the proposed FS-FNDPLL employs a new background gain calibrated digital-to-time converter (BGC-DTC) as a fractional divider in the feedback path for the quantization noise cancellation (QNC). The proposed FMCW transmitter uses an R-PILO to produce fast switching adjacent carriers after generating a narrowband chirp using FS-FNDPLL. The main features of the proposed FMCW to accelerate settling time with AC-TDCSw, BGC-DTC and the integration of spur suppressing pulse generator (SSPG) in R-PILO enable ultra-fast chirps with less phase noise and spur levels. The proposed transmitter up-converts the 500MHz narrowband chirp signal onto four adjacent carriers for obtaining a 2GHz chirp at the C-band. The simulation results prove that the proposed FMCW Transmitter consumes 79mW power. Furthermore, the phase noise of the proposed FS-FNDPLL is reduced to $-113$dBc/Hz at 1MHz. The proposed FS-FNDPLL reduces the settling time to 1$\mu$s with the introduced AC-TDCSw scheme.

A 20-channel liquid crystal display (LCD) driver architecture is implemented with $0.18\mu$m CMOS technology. This work presents a novel design of 10-bit compact and high-resolution two-stage DAC to improve the linearity and uniformity of each channel performance. A complete column driver, including a compact DAC, low power buffer, global R-string and multiplexing circuit design, is implemented, and the layout of this 20-channel, 10-bit LCD driver is generated using $0.18\mu$m CMOS technology. All the circuit blocks of the proposed LCD column driver were simulated using the EDA tool HSPICE and layout generation by Laker. This work also realizes a high-performance class AB operational amplifier with a gain of 140dB for the proposed LCD driver. The 10-bit compact LCD driver has a 1.4 mV LSB and an output voltage of 1.7 V is achieved for the input range of 0.25–1.7V. The compact DAC voltage selector with decoder in this design uses fewer switches in comparison to conventional tree-type RDAC, occupying a smaller chip area with fast response. The proposed design is sufficiently robust for high-color depth and resolution LCD driver applications. The experimental results exhibit maximum differential nonlinearity (DNL) and integral nonlinearity (INL) of 0.065 LSB and −0.12 LSB, respectively. The one channel area is $951.69\mu \mathrm{\text{m}}\times 17.8\mu$m and the settling time is $5.65\mu$s for the $20\mathrm{\text{k}}\mathrm{\Omega }$ and 20pF driving load.