Title:
CURRENT DETECTION CIRCUIT, PHOTORECEIVER USING THE SAME, LIGHT EMISSION CONTROL DEVICE, AND ELECTRONIC DEVICE USING THE SAME
Document Type and Number:
WIPO Patent Application WO/2007/043282
Kind Code:
A1
Abstract:
There is provided a current detection circuit capable of performing a stable
current detection. A first transistor (Q1) is provided on a current path of a photo
transistor (210). A bias current path (12) includes a bias switch (SW1) and a first
bias resistor (Rbias1) connected in series and arranged in parallel to a main
current path (10) including the photo transistor (210). A second transistor
(Q2) constitutes a current mirror circuit together with the first transistor
(Q1) and generates a second current (Iq2) obtained by multiplying a first current
(Iq1) flowing in the first transistor (Q1) by a predetermined number. The second
current (Iq2) is charged to a charge capacitor (Cchg) and converted into voltage.
The bias current path (12) is turned ON before photoreception start of the photo
transistor (210) and is turned OFF when a predetermined time has elapsed after
start of photoreception by the photo transistor (210).
Inventors:
TAMEGAI, Yoichi (21, Saiin Mizosaki-Cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 6158585, JP)
爲我井 洋一 (〒85 京都府京都市右京区西院溝崎町２１ ローム株式会社内 Kyoto, 6158585, JP)
NATE, Satoru (21, Saiin Mizosaki-Cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 6158585, JP)
爲我井 洋一 (〒85 京都府京都市右京区西院溝崎町２１ ローム株式会社内 Kyoto, 6158585, JP)
NATE, Satoru (21, Saiin Mizosaki-Cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 6158585, JP)
Application Number:
JP2006/318288
Publication Date:
April 19, 2007
Filing Date:
September 14, 2006
Export Citation:
Assignee:
ROHM CO., LTD. (21 Saiin Mizosaki-Cho, Ukyo-ku Kyoto-sh, Kyoto 85, 6158585, JP)
ローム株式会社 (〒85 京都府京都市右京区西院溝崎町２１ Kyoto, 6158585, JP)
TAMEGAI, Yoichi (21, Saiin Mizosaki-Cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 6158585, JP)
爲我井 洋一 (〒85 京都府京都市右京区西院溝崎町２１ ローム株式会社内 Kyoto, 6158585, JP)
ローム株式会社 (〒85 京都府京都市右京区西院溝崎町２１ Kyoto, 6158585, JP)
TAMEGAI, Yoichi (21, Saiin Mizosaki-Cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 6158585, JP)
爲我井 洋一 (〒85 京都府京都市右京区西院溝崎町２１ ローム株式会社内 Kyoto, 6158585, JP)
International Classes:
G01J1/44; G01R19/145; G03B7/16; G03B15/02; G03B15/03; G03B15/05; H01L31/10; H04N5/238; G01J1/44; G01R19/145; G03B7/16; G03B15/02; G03B15/03; G03B15/05; H01L31/10; H04N5/238
Attorney, Agent or Firm:
MORISHITA, Sakaki (2-11-12, Ebisu-Nishi Shibuya-ku, Tokyo 21, 1500021, JP)