Title:
A/D CONVERTER
Document Type and Number:
Japanese Patent JP3254897
Kind Code:
B2
Abstract:
PURPOSE: To measure very small measured voltage more accurately by providing a resistor between an output terminal of a triangle wave generator and ground so as to attain the voltage outputted from the triangle wave generator with excellent linearity.
CONSTITUTION: A pull-down resistor 18 as a resistor is provided between an output terminal 11c of an operational amplifier 11 of a triangle wave generator 1 and ground. When a clock pulse V0 whose period is T is given to inverting input terminal of the operational amplifier 11 via a resistor 13, a nearly triangle voltage V1 whose period is T is outputted from an output terminal 11c. That is, when the level of the pulse V0 is at an L, since a capacitor 12 is gradually discharged, the voltage V1 is being increased. Since the capacitor 12 is gradually charged when the pulse V0 is at an H, the voltage V1 is being decreased up to a lower limit. Thus, the voltage V1 draws nearly a triangle wave. The gradient of the voltage V1 after undershoot is caused in the voltage V1 by adjusting the resistance of the resistor 18 and the waveform of the V1 has a rising gradient with excellent linearity.
Inventors:
Masaaki Sakagami
Takio Maekawa
Takio Maekawa
Application Number:
JP10872694A
Publication Date:
February 12, 2002
Filing Date:
May 23, 1994
Export Citation:
Assignee:
MATSUSHITA ELECTRIC WORKS,LTD.
International Classes:
H03M1/56; H03K7/08; (IPC1-7): H03M1/56; H03K7/08
Domestic Patent References:
| JP3135231A | ||||
| JP56176541U |
Attorney, Agent or Firm:
Junji Ando (1 person outside)