This article is an excellent introduction to analog filters. It covers the basic first and second order filter types as well as the advantages and disadvantages of passive and active filters. It derives and analyzes the basic biquad implementation using several op amp implementation examples. The world of filter design is often thought of as black magic because of the myriad of configurations, ...

In recent years, Electrical Bioimpedance (EBI) methods have gained importance. These methods are often based on obtaining impedance spectrum in the range of β-dispersion, i.e. from a few kHz up to some MHz. To measure EBI a constant current is often injected and the voltage across the tissue under study is recorded. Due to the performance of the current source influences the performance of the ...

This low-power sigma-delta modulator targets the DVB-H requirements and achieves about 10 bit with 6-MHz signal band and a FoM of 0.59 pJ/conversion. The used scheme is a multi-bit third order modulator that, with suitable topological modification, enables using two op-amps and enjoying a swing reduction at the quantizer input. The area of the circuit, fabricated with a 0.18-μm analog CMOS tech...

Split Supplies Vs. Single Supply All op amps have two power pins. In most cases, they are labeled VCC + and VCC-. Sometimes, however, they are labeled VCC and GND. This is an attempt on the part of the data sheet author to categorize the part as a split-supplies or single-supply part. It does not mean, however, that the op amp has to be operated that way. It may or may not be able to operate fr...

Audio Applications for Op-Amps, Part III By Bruce Carter Advanced Analog Products, Op Amp Applications Texas Instruments Incorporated This is the third in a series of articles on single-supply audio circuits. The reader is encouraged to review the introductory material in the first article which concentrated on low-pass and high-pass filters. The second article concentrated on audio notch filte...

Background: Good antenatal care helps a woman face labour in good health and optimum conditions. The National Institute for Health Care Excellence (NICE) WHO guidelines suggest 15 visits the whole pregnancy. Keeping view COVID-19 pandemic to reduce exposure of pregnant ladies number was reduced 7 milestone outcome noted. This study aimed do comparative feto-maternal cases at our centre using st...

Two new class AB output stages for CMOS op-amps are proposed with accurate quiescent current control. The second proposed stage also provides accurate control of the minimum current through the output transistors. The proposed stages can be operated with a supply voltage close to a transistor threshold voltage. A dynamic biasing scheme allows them to operate in a wide range of supply voltages. ...