The paper presents a new approach to design of current amplifiers. The amplifying cell core represents the connection of three transistors: a bias transistor and a differential pair. The bias transistor sets the distribution of currents in the differential pair. When an external current signal is applied to the core input the outputs of the differential pair provide two complementary current signals. The loading of the differential pair by a current mirror provides current conversion, and, depending on the current mirror orientation, one obtains a positive or negative current amplifying stage. These stages can be directly cascaded to obtain multistage high current gain amplifier. The gain of multistage amplifier may be stabilized using an external resistive current divider or external differential pair used as current distributor. The paper considers static and dynamic characteristics of the amplifying stages, and the frequency response of the two-stage amplifier. The amplifier was designed for 45 nm CMOS technology, the simulation was done using Cadence. The results of calculations and simulations are in a reasonable agreement.Index Terms-Current amplifiers, wide-band amplifiers, multistage amplifiers, feedback amplifiers, current follower.
The paper demonstrates that the source follower is the core of such seemingly disparate circuits as the wideband amplifier, crystal oscillator and emitter-coupled multivibrator. It is shown that the input impedance of the follower loaded by a capacitor has a negative real part. This part compensates partially or completely the resistive component of the signal source impedance. The compensation develops a strong overshoot in the step-signal transmission; in case of inductive component in the source impedance the circuit may operate as well as oscillator. The oscillators can be also obtained coupling two source followers; this may result in new oscillator circuits.
A novel and simple solution for adjusting dead time in high speed DC-DC converters is proposed. The usual dead time adjustment of DC-DC converters through feedback control has limited speed. For the high speed converters extra circuitry and delays in the feedback should be minimized. A 240 MHz DC-DC converter with the presented dead time circuit is designed on low-voltage fast CMOS process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.