公开(公告)号：US20010043096A1

公开(公告)日：2001-11-22

申请号：US09824534

申请日：2001-04-02

申请人： STMicroelectronics S.r.l.

发明人： Davide Brambilla ,  Mauro Cleris

IPC分类号： H03K004/06

CPC分类号： H03K4/06 ,  H03K4/023

摘要： An integrated circuit for producing a small slope voltage ramp includes a circuit for generating a periodic triangular current signal, and a circuit for generating, at the beginning of each period of the triangular signal, a pulse of a certain duration which is much smaller than the period of the triangular signal. A control loop is input at a node with the triangular current signal and produces the desired slow voltage ramp on the output node. The control loop includes a first hold circuit coupled to the input node via a first switch controlled by the pulse, and a transconductance operational amplifier, whose inputs are respectively coupled to the input node and to the output node. Also, the control loop includes a second hold circuit coupled to the output of the operational transconductance amplifier via a second switch controlled in a complementary manner with respect to the first switch. A resistor of a much smaller value than the ratio between the period of the triangular signal and the capacitance of the storage capacitor of the first hold circuit is connected between the output of the second hold circuit and the input node.

摘要翻译： 用于产生小斜坡电压斜坡的集成电路包括用于产生周期性三角形电流信号的电路，以及用于在三角形信号的每个周期的开始处产生一定长度的脉冲，该脉冲远小于 三角形信号周期。 在具有三角形电流信号的节点处输入控制回路，并在输出节点上产生所需的慢速电压斜坡。 控制回路包括通过由脉冲控制的第一开关耦合到输入节点的第一保持电路和跨导运算放大器，其输入分别耦合到输入节点和输出节点。 而且，控制回路包括第二保持电路，该第二保持电路通过相对于第一开关以互补方式控制的第二开关耦合到运算跨导放大器的输出端。 在第二保持电路的输出和输入节点之间连接有比三角形信号的周期和第一保持电路的存储电容的电容之间的比值小得多的电阻。