公开(公告)号：EP1306975A1

公开(公告)日：2003-05-02

申请号：EP01830675.3

申请日：2001-10-29

Applicant: STMicroelectronics S.r.l.

Inventor： Curatolo, Giacomo ,  Martines, Ignazio ,  Torrisi, Davide

IPC: H03K19/003 ,  H03K17/16

CPC classification number: H03K19/00361 ,  H03K17/167

Abstract: An output buffer for causing a voltage ( Vout ) of an integrated circuit output line ( OUT,OUT_PAD ) to switch from a voltage of a first voltage line ( VDD ) to a voltage of a second voltage line ( GND ) and vice versa, comprises a current path switch circuit ( 111a, 111b ) activatable for causing a prescribed current ( Is ) to constantly flow between the first and second voltage lines during a time between two successive switchings of the output line, and for causing the prescribed current to be deviated ( Ic1 ) to the output line during at least an initial phase of an output line switching from the first voltage line voltage to the second voltage line voltage or vice versa. A current delivered by that voltage line, among the first and second voltage lines, which plays an active role is thus kept substantially constant in the output line switching. In this way, the time derivative of the current flowing between the first and the second voltage lines is kept small and low switching noise is induced.

Abstract translation: 一种用于使集成电路输出线（OUT，OUT_PAD）的电压（Vout）从第一电压线（VDD）的电压切换到第二电压线（GND）的电压的输出缓冲器，反之亦然，包括 一个电流路径切换电路（111a，111b），用于在输出线两次连续切换之间的时间内使规定电流（Is）恒定地在第一和第二电压线之间流动，并使规定电流偏离 （Ic1）在从第一电压线电压切换到第二电压线电压的输出线的至少初始相位期间到输出线，反之亦然。 因此，在输出线切换中，起着主动作用的第一和第二电压线之间由该电压线传递的电流基本保持恒定。 以这种方式，在第一和第二电压线之间流动的电流的时间导数保持较小，并且引起低的开关噪声。