公开(公告)号：JPS648677A

公开(公告)日：1989-01-12

申请号：JP9472088

申请日：1988-04-19

Applicant: IBM

Inventor： DENISU RII ROJIYAASU ,  JIERII MAKUFUAASON UTSUDORU ,  JIYOOJI DEBUIDO PETEITO ,  DEBUIDO TEIRAA MAKUINTAAFU

IPC: H01L31/09 ,  G01J1/02 ,  H01L31/00 ,  H01L31/0304 ,  H01L31/108 ,  H01L31/109

Abstract: PURPOSE: To suppress the tunneling of charge carriers of an electric current passing under a Schottky barrier by providing a heterojunction surface layer which prevents the carriers from being caught on the surface by repulsing the carriers among alternately inserting type metallic, semiconductor, and metallic electrodes arranged on the surface of a gallium arsenide semi-insulating semiconductor material. CONSTITUTION: The main body 12 of a photodetector 10 is divided into an upper layer 14 and a lower layer 16. A set of alternately inserting type electrodes 18 is arranged on the top of the upper layer 14. The electrodes 18 contain an anode 18A connected to the anode terminal of a battery 22 through a resistor 20 and a cathode 18B connected to the cathode terminal of the battery 22. The battery 22 works as a voltage biasing source for the action of the photodetector 10 and the resistor 20 causes a voltage drop proportional to the detecting current flowing through the photodetector 10. The upper layer 14 is a heterojunction layer having a wider forbidden band that the lower layer 16 has. Therefore, an electric field which repulses electrons and holes from the surface of a device is generated and the charge carriers which are caught on the surface of the device decrease.

公开(公告)号：JPS6319881A

公开(公告)日：1988-01-27

申请号：JP12728387

申请日：1987-05-26

Applicant: IBM

Inventor： DENISU RII ROJIYAASU

IPC: H01L31/00 ,  H01L31/0224 ,  H01L31/0248 ,  H01L31/0264 ,  H01L31/10 ,  H01L31/108

公开(公告)号：JPH08233870A

公开(公告)日：1996-09-13

申请号：JP27935095

申请日：1995-10-26

Applicant: IBM

Inventor： DENISU RII ROJIYAASU

IPC: G01R19/02 ,  G01R19/04 ,  H03K5/1532

Abstract: PROBLEM TO BE SOLVED: To detect both a peak value and an average value of signals by a single circuit, by providing mutually supplementary switches each having an input terminal and an output terminal and switchable by a common switching input. SOLUTION: In a peak detection mode, an n-channel FETQ1 is turned on and a p-channel FETQ2 is turned off, whereby the circuit is operated as a peak detection circuit. In an averaging mode, the Q1 is turned off and the Q2 is turned on, so that signals are connected to a capacitor C1 via a resistor R1 thereby to form an averaging circuit. In this averaging mode, a positive input of an amplifier A1 is lowered either by a resistor R2 or by a regular leak current at an input terminal of the A1. Accordingly, an output of the A1 is decreased, inversely biasing a diode D1. In consequence, the A1 is effectively shut from the C1.

公开(公告)号：JPH08213852A

公开(公告)日：1996-08-20

申请号：JP27924195

申请日：1995-10-26

Applicant: IBM

Inventor： DENISU RII ROJIYAASU ,  MAAKU BII RITSUTAA

IPC: H03F3/08 ,  H04B10/04 ,  H04B10/06 ,  H04B10/14 ,  H04B10/26 ,  H04B10/43 ,  H04B10/28

Abstract: PROBLEM TO BE SOLVED: To shunt the excessive photoelectric current of an optical receiver by providing a shunt circuit which prevents the output current of a photodetector which receives optical pulses from reaching the input of an amplifier when the current exceeds a prescribed threshold. SOLUTION: A clamp circuit is composed of resistors R1 and R2 respectively connected to a photodiode and the cathode of the photodiode, capacitors C2 and C3 respectively connected to the junctions of the resistors R1 and R2, and a differential amplifier circuit A1 connected to both ends of the photodiode. When the output current of the photodiode exceeds a prescribed threshold, the output current is prevented from flowing in the amplifier A1 by short- circuiting the excessive current by turning on FETs Q1 and Q2.

公开(公告)号：JPS57176814A

公开(公告)日：1982-10-30

申请号：JP5393682

申请日：1982-04-02

Applicant: IBM

Inventor： DENISU RII ROJIYAASU ,  ARUBAATO ZABIERU UIDOMAA

IPC: H03F3/42 ,  H03F3/45