نمونه متن انگلیسی مقاله
A recycling amplifier architecture based on the folded cascode transconductance amplifier is described. The proposed amplifier delivers an appreciably enhanced performance over that of the conventional folded. This is achieved by using previously idle devices in the signal path, which results in an enhanced transconductance, gain, and slew rate. Moreover, the input referred noise and offset analyses are included to demonstrate that the proposed modifications have no adverse effects on these design metrics. Transistor-level simulations and experimental results in TSMC 0.18 m CMOS process confirm the theoretical results. When compared to the conventional folded cascode, and for the same area and power budgets, the proposed amplifier has almost twice the bandwidth (134.2 MHz versus 70.7 MHz) and better than twice the slew rate (94.1 V s versus 42.1 V s) while driving the same 5.6 pF load. Also a gain enhancement of 7.6 dB is observed.
T HE advancement of CMOS technologies paved the road for a growing market of mobile and portable electronic devices. This growth is driven by the continual integration of complex analog and digital building blocks on a single chip, making silicon area and power consumption the two most valued aspects of a design. The operational transconductance amplifier (OTA) is still a vital analog building block and for many applications is the largest and most power consuming. Recently, one of the most commonly used architectures, whether as a single-stage or first stage in multi-stage amplifiers, had been the folded cascode (FC) amplifier for its high gain and reasonably large signal swing in the present and future low voltage CMOS processes. Moreover, the PMOS input FC has become the prime choice over its NMOS counterpart for its higher non-dominant poles, lower flicker noise, and input common mode level. The latter allows input switching using a single NMOS transistor in switched-capacitor (SC) applications , . Previous work to enhance the performance of the FC used multi-path schemes  and . Another multi-path scheme  was applied to the Three-Current-Mirror OTA to enhance the output impedance and slew rate, and another in  to emulate a class AB operation. However, they were not suitable for high-speed applications as the transfer function of the OTA had numerous low frequency pole-zero pairs. Nonetheless, – form the basis of the proposed modifications to the FC amplifier presented in Section II. In Section III, the effects of these modifications on the major design metrics of the proposed FC amplifier are presented, whereas Sections IV and V discuss the implementation, and experimental/simulations results respectively. Finally, the conclusions are presented in Section VI.