Single-amplifier filter biquads and especially Sallen-Key filters are widely used to build higher-order filter cascades. This paper investigates high-frequency current amplifier non-idealities and their effects on all-pole Sallen-Key filter biquads. It is shown that a non-ideal current amplifier input causes parasitic zeros in the filter transfer function, and thus imposes fundamental limitatio...

In this paper, a compact low-power (LP) low-voltage (LV) metal–oxide–semiconductor-only (MOS-only) variable gain amplifier (VGA) is introduced. This amplifier based on complementary MOS (CMOS) transistors operating in strong inversion is composed of a pseudo-exponential current-to-voltage converter, analog multiplier, and output stage. The gain of the amplifier is controlled exponentially by a ...

Active filters play important role in communication systems. They can be obtained and constructed by different methods. Recently, there is a tendency of designing current-mode circuits using unity-gain active elements such as, CFOAs, CCIIs, etc. instead of classical infinite gain operational amplifiers in active filter design. This paper presents transresistance multifunction filter realization...

The OPA681 sets a new level of performance for broadband current feedback op amps. Operating on a very low 6mA supply current, the OPA681 offers a slew rate and output power normally associated with a much higher supply current. A new output stage architecture delivers a high output current with minimal voltage headroom and crossover distortion. This gives exceptional single-supply operation. U...

A high-performance CMOS unity-gain current amplifier is proposed. The solution adopts two feedback loops to reduce the input resistance and a nested-Miller technique to provide frequency compensation. A design example using a 0.8 mm process and a 2V supply is given and SPICE simulations show a bandwidth of 75MHz, no slew-rate limitations and a settling time better than 50 ns, irrespective of th...

A single-stage 24 GHz triple stacked power amplifier using 0.13 μm CMOS process is demonstrated. To Compare with parallel current combining method, series voltage combining method using a stacked amplifier architecture can realize a large output voltage swing from the top transistor without exceeding the transistor breakdown voltage limitations. However, at high frequencies, parasitic capacitan...