公开(公告)号：EP0905925A3

公开(公告)日：2001-03-14

申请号：EP98306535.0

申请日：1998-08-17

申请人： Sharp Kabushiki Kaisha

发明人： Yokogawa, Naruichi ,  Okuda, Takanori ,  Shimizu, Takayuki

IPC分类号： H04B10/158 ,  H03F3/08

CPC分类号： H04B10/114

摘要： A light receiving amplifying device of the present invention includes (1) a light receiving device for outputting a light signal current which varies with a quantity of received light, (2) a load resistor connected with the light receiving device in series, for generating a detected voltage which varies with the light signal current, (3) a low frequency current bypass circuit for preventing the detected voltage from being saturated when the detected voltage has a frequency in a low frequency band, the low frequency current bypass circuit being connected with the load resistor in parallel and having an input impedance varying with a frequency of the detected voltage, (4) a transimpedance amplifying circuit (inverting amplifying circuit) for transforming an impedance of the detected voltage, and (5) a capacitor for coupling the low frequency current bypass circuit and the transimpedance amplifying circuit (inverting amplifying circuit). This makes it possible, with a relatively simple circuit and arrangement in an infrared communication receiver, to lower noises of the light receiving amplifying device while maintaining an operational range with respect to a DC photoelectric current.

公开(公告)号：EP0903751A2

公开(公告)日：1999-03-24

申请号：EP98306518.6

申请日：1998-08-14

申请人： Sharp Kabushiki Kaisha

发明人： Okuda, Takanori ,  Yokogawa, Naruichi

IPC分类号： G11C27/02

CPC分类号： H03K5/1532 ,  H03G3/3084 ,  H03K5/084

摘要： In a peak-hold circuit, a hold capacitor captures the peak value of an input signal and a reset section carries out a resetting operation on the holding value of the hold capacitor when, upon switching inputs, it receives a reset signal. The reset section, upon receipt of the reset signal, improves the response speed of a peak-hold section by a predetermined time period. The reset section is provided with a constant current circuit and a switching means for increasing a charging current and a discharging current of the peak-hold section respectively.

摘要翻译： 在峰值保持电路中，保持电容捕获输入信号的峰值，并且当切换输入时，复位部分接收复位信号，对保持电容器的保持值执行复位操作。 复位部分在接收到复位信号时，将峰值保持部分的响应速度提高预定时间段。 复位部分设置有恒流电路和用于分别增加峰值保持部分的充电电流和放电电流的开关装置。