Title:
DIGITAL-ANALOG CONVERSION CIRCUIT AND METHOD THEREOF, AND METHOD OF DETERMINING NUMBER OF TAP OF FILTER AND TAP WEIGHT COEFFICIENT
Document Type and Number:
Japanese Patent JPH03242025
Kind Code:
A
Abstract:
PURPOSE: To reduce noise and to make distortion low by making a signal on an addition node an analog signal that corresponds to digital input data and making the capacitance of a signal capacitor represent a tap weight coefficient which is corresponded to by a finite impulse response filter. CONSTITUTION: A digital audio converter 10 has a source 11 such as a digital audio tape(DAT) and a compact disc(CD), 64 times over sampler 12, a finite impulse response(FIR) interpolator 13, a Σ-Δencoder 14, a combined switching capacitor finite impulse response filter and digital-to-analog converter 15 (FIR /DAC) and a low-pass filter 16. Here, a signal of an addition node is analog signal that corresponds to digital input data, and the capacitance of a signal capacitor represents a tap weight coefficient of the finite impulse response filter. This makes it possible to reduce out of band noise and accomplish lower distortion.
Inventors:
JIEFURII UIRIAMU SUKOTSUTO
SAYAMUKURANGARA RAMASUWAMI BIS
SAYAMUKURANGARA RAMASUWAMI BIS
Application Number:
JP26398690A
Publication Date:
October 29, 1991
Filing Date:
October 03, 1990
Export Citation:
Assignee:
AMERICAN TELEPHONE & TELEGRAPH
International Classes:
H03M3/04; G11B20/10; H03H17/00; H03H17/06; H03H19/00; H03H21/00; H03M3/02; (IPC1-7): H03H17/02; H03M3/04
Domestic Patent References:
| JPS59174018A | 1984-10-02 | |||
| JPS6096014A | 1985-05-29 | |||
| JPS62168412A | 1987-07-24 | |||
| JPS6471210A | 1989-03-16 |
Attorney, Agent or Firm:
Hirofumi Mimata (1 person outside)
Previous Patent: Packaging structure for absorbent articles
Next Patent: DC SUPPRESSION SYSTEM, FOR CODE STRING
Next Patent: DC SUPPRESSION SYSTEM, FOR CODE STRING