Design of tunable second order frequency filter in CMOS technology

Tato diplomová práce se zabývá návrhem laditelného kmitočtového filtru druhého řádu v technologii CMOS. Práce sestává z návrhu transkonduktoru a jeho využití pro laditelný filtr v topologii gm-C. Návrh i všechny simulace byly provedeny v programu Cadence Spectre a Virtuoso. V omezené míře bylo využito i programů Orcad PSpice a SNAP.This master’s thesis deals with the design of tuneable frequency second order filter in CMOS technology. The thesis describes the design of a transconductor and its utilization for tunable gm-C filter. The design and all simulations were made in Cadence Spectre and Virtuoso software. Limitedly Orcad Pspice and SNAP were also used.

Design and realization of an active subwoofer

Tato bakalářská práce se zabývá návrhem a realizací jednokanálového zesilovače pro aktivní subwoofer o maximálním výkonu 200 W na 8 zátěž. Návrh sestává z aktivního korekčního předzesilovače a koncového stupně. Předzesilovač je tvořen integrovanými operačními zesilovači a je ovládán dvěma potenciometry, přepínačem vstupů a přepínačem fáze. Koncový stupeň je tvořen integrovanými obvody LM3886T od firmy Texas Instruments. Oba bloky byly zrealizovány na desky plošných spojů a byly změřeny jejich parametry.This bachelor thesis describes the design and construction of a one-channel amplifier 200 W into 8 load for an active subwoofer. The design consists of an active correction preamplifier and output stage. Preamplifier is created of integrated operational amplifiers and is controlled by two potentiometers, input switch and phase switch. Output stage is created of integrated circuits LM3886T by Texas Instruments. Both stages were constructed on PCBs and were measured their parameters.

Stereoselective palladium-catalyzed functionalization of homoallylic alcohols: a convenient synthesis of di- and trisubstituted isoxazolidines and β-amino-δ-hydroxy esters

Enantiopure, Boc-protected alkoxyamines 12 and 13, derived from the readily available homoallylic alcohols 4 via a reaction that involves either inversion or retention of configuration, undergo a diastereoselective Pd-catalyzed ring-closing carbonylative amidation to produce isoxazolidines 16/17 (≤50:1 diastereoisomer ratio (d.r.)) that can be readily converted into the N-Boc-protected esters of β-amino-δ-hydroxy acids and their γ-substituted homologues 37. The key carbonylative cyclization proceeds through an unusual syn addition of the palladium and the nitrogen nucleophile across the C[DOUBLE BOND]C bond (19→21), as revealed by the reaction of 15, which afforded isoxazolidine 18 with high diastereoselectivity