Controllable oscillator

专利名称：Controllable oscillator

发明人：Kasperkovitz, Wolfdietrich Georg申请号：EP01201441.1申请日：20010420公开号：EP1251633A1公开日：20021023

专利附图：

摘要：Controllable oscillator circuit comprising a regenerative loop which

incorporates a cascade circuit of first and second sections each having a controllable gainand a phase shift which is 90° at the oscillation frequency, the first and second sectionscomprising first and second transconductance amplifiers, respectively, outputs of which

are coupled to third and fourth transconductance amplifiers, which are positively fedback from the output to the input, and via first and second capacitors to inputs of thesecond and first gain controlled amplifiers, said first and second capacitors being coupledin parallel to first and second load resistors, respectively, a tuning control current beingsupplied to control inputs of the first and second transconductance amplifiers, theoutput of at least one of the first and second transconductance amplifiers being coupledto an amplitude detection arrangement providing a gain control current for an automaticgain control to control inputs of the third and fourth transconductance amplifiers, saidfirst and third transconductance amplifiers of the first section having a differential pair offirst and second output terminals in common, said second and fourth transconductanceamplifiers of the second section having a differential pair of third and fourth outputterminals in common. In order to provide an oscillator capable of generating sinusoidalsignals and tuneable at lower tuning frequencies and operating at lower supply voltagesthan the above conventional oscillator circuit, said first and second parallel RC filters arecoupled between the first and second output terminals and the third and fourth outputterminals, respectively, said first to fourth output terminals being respectively coupled tofirst to fourth DC current paths shunting at least a substantial part of said tuning andgain control currents to a supply voltage.

申请人：Semiconductor Ideas to The Market (ItoM) BV

地址：Drielindendreef 53 4839 AH Breda NL

国籍：NL

代理机构：Van Straaten, Joop

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