公开(公告)号：JPH08123412A

公开(公告)日：1996-05-17

申请号：JP25859294

申请日：1994-10-24

Applicant: UNITED MICROELECTRONICS CORP

Inventor： CHIMAO FUAN

IPC: G10H7/02 ,  G10H1/057 ,  G10K15/04 ,  G10L21/02 ,  H03M1/74 ,  G10L3/02

Abstract: PURPOSE: To provide an analog synthesized musical sound inverter with the simple structure at a low cost by proportioning an output value of the converting current to a current change of the product of envelope and tone, and feeding the current, which compensates the envelop generating unit with each other. CONSTITUTION: An envelope current generating unit 30 and a tone current generating unit 40 are connected to a right side of a referential current generating unit 20 in order. A direct current drift compensating unit 70 is formed by connecting a compensating current generating unit 50 and a current amplifying unit 60 in series. In this case, total current variable (Ib1+Ib2) of the compensating current generating unit 50 and the envelope current generating unit 30 is constant. Namely, when one of current variable is increased, the other current variable is reduced. The current amplifying unit 60 following to the compensating current generating unit 50 uses an intermediate value of tone. The output signal value I0 of an analog converter 10 is in proportion to the product of tone T and envelope E, and a D/A converter, which can achieve the effect by multiplying the tone signal and the envelope signal, is formed.