Title:
DDSパルス発生装置
Document Type and Number:
Japanese Patent JP4277091
Kind Code:
B2
Abstract:
A DDS pulse generator has an accumulator that accumulates a phase increment value to produce phase accumulator values, and has a lookup table that contains a digital representation of a pulse waveform such that a pulse output signal is produced from the lookup table in response to the phase accumulator values. To change a period of the pulse output signal without changing edge positions a programmable modulo value is used. An address mapper is situated between the accumulator and address lines of the lookup table to map the rising and falling edge portions of the phase accumulator values into large regions of the lookup table, while phase accumulator values corresponding to high and low logic levels are mapped into small regions of the lookup table. The resulting pulse output signal has easily independently controlled period and pulse width as well as rising and falling edge speeds. By making better use of the lookup table it is possible to generate very narrow pulses with low repetition rates or pulses in which the rise time and fall time are very different from the period.
Inventors:
Stephen Kay Sullivan
Raymond El Vace
Akiyama Iwao
Fujisawa Taizen
Raymond El Vace
Akiyama Iwao
Fujisawa Taizen
Application Number:
JP2004366070A
Publication Date:
June 10, 2009
Filing Date:
December 17, 2004
Export Citation:
Assignee:
Tektronix International Sales GmbH
International Classes:
H03K3/64; G06F1/03; G06G7/26; H03B1/00; H03B28/00; H03K3/78
Domestic Patent References:
| JP7231225A | ||||
| JP7106854A | ||||
| JP3253108A | ||||
| JP2003196580A | ||||
| JP2003500958A | ||||
| JP2000278048A |
Attorney, Agent or Firm:
Nippon Tektronix Co., Ltd.