Title:
デジタルアナログ変換器
Document Type and Number:
Japanese Patent JP2004528780
Kind Code:
A
Abstract:
A method and circuit are provided for converting a digital signal to an analog signal in the form of a pulse width modulated (PWM) pulse (20). The PWM pulse is generated during an output cycle of a pulse generator to form a pulsetrain output of pulses at a fixed frequency whose widths are determined by dynamically changing digital input data. The method includes the steps of dividing the digital data signal into most significant bit (MSB) and least significant bit (LSB) portions. A PWM pulse is initiated at the beginning of an output cycle and continues while the MSB portion counts down in a counter (24). At the same time, the LSB portion of the digital data signal is converted to a precise phase delay signal which is a subcycle of an oscillator controlling the counter. This phase delay signal is generated after the termination of the MSB count, and halts the high period of the PWM pulse during the output cycle. When the output cycle ends, the process is repeated with the next digital signal.
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Inventors:
Brian donovan
Ray S McKayg
Ray S McKayg
Application Number:
JP2002590510A
Publication Date:
September 16, 2004
Filing Date:
May 13, 2002
Export Citation:
Assignee:
Zylon Corporation
International Classes:
H03M1/68; H03M1/82; (IPC1-7): H03M1/82
Attorney, Agent or Firm:
Kosaku Sugimura